ORCID Profile
0000-0003-4216-8701
Current Organisations
Advanced Telecommunications Research (ATR)
,
Center for Information and Neural Networks (CiNet),
,
Monash University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Sensory Systems | Sensory Processes, Perception and Performance | Psychology | Central Nervous System | Neurocognitive Patterns and Neural Networks | Neurosciences | Computer Perception, Memory and Attention
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Psychology and Cognitive Sciences | Expanding Knowledge in the Biological Sciences | Expanding Knowledge in the Information and Computing Sciences | Mental Health | Expanding Knowledge in the Medical and Health Sciences |
Related Links
Publications
Attention periodically samples competing stimuli during binocular rivalry
Publisher: eLife Sciences Publications, Ltd
Date: 03-12-2018
DOI: 10.7554/ELIFE.40868
Abstract: The attentional s ling hypothesis suggests that attention rhythmically enhances sensory processing when attending to a single (~8 Hz), or multiple (~4 Hz) objects. Here, we investigated whether attention s les sensory representations that are not part of the conscious percept during binocular rivalry. When crossmodally cued toward a conscious image, subsequent changes in consciousness occurred at ~8 Hz, consistent with the rates of un ided attentional s ling. However, when attention was cued toward the suppressed image, changes in consciousness slowed to ~3.5 Hz, indicating the ision of attention away from the conscious visual image. In the electroencephalogram, we found that at attentional s ling frequencies, the strength of inter-trial phase-coherence over fronto-temporal and parieto-occipital regions correlated with changes in perception. When cues were not task-relevant, these effects disappeared, confirming that perceptual changes were dependent upon the allocation of attention, and that attention can flexibly s le away from a conscious image in a task-dependent manner.
Opposing effects of attention and consciousness on afterimages
Publisher: Proceedings of the National Academy of Sciences
Date: 27-04-2010
Abstract: The brain's ability to handle sensory information is influenced by both selective attention and consciousness. There is no consensus on the exact relationship between these two processes and whether they are distinct. So far, no experiment has simultaneously manipulated both. We carried out a full factorial 2 × 2 study of the simultaneous influences of attention and consciousness (as assayed by visibility) on perception, correcting for possible concurrent changes in attention and consciousness. We investigated the duration of afterimages for all four combinations of high versus low attention and visible versus invisible. We show that selective attention and visual consciousness have opposite effects: paying attention to the grating decreases the duration of its afterimage, whereas consciously seeing the grating increases the afterimage duration. These findings provide clear evidence for distinctive influences of selective attention and consciousness on visual perception.
Detecting (Un)seen Change: The Neural Underpinnings of (Un)conscious Prediction Errors
Publisher: Frontiers Media SA
Date: 11-11-2020
SURPRISING THREATS ACCELERATE EVIDENCE ACCUMULATION FOR CONSCIOUS PERCEPTION
Publisher: Cold Spring Harbor Laboratory
Date: 25-01-2019
DOI: 10.1101/525519
Abstract: Our survival depends on how well we can rapidly detect threats in our environment. To facilitate this, the brain is faster to bring threatening or rewarding visual stimuli into conscious awareness than neutral stimuli. Unexpected events may indicate a potential threat, and yet we tend to respond slower to unexpected than expected stimuli. It is unclear if or how these effects of emotion and expectation interact with one’s conscious experience. To investigate this, we presented neutral and fearful faces with different probabilities of occurance in a breaking continuous flash suppression (bCFS) paradigm. Across two experiments, we discovered that fulfilled prior expectations hastened responses to neutral faces but had either no significant effect (Experiment 1) or the opposite effect (Experiment 2) on fearful faces. Drift diffusion modelling revealed that, while prior expectations accelerated stimulus encoding time (associated with the visual cortex), evidence was accumulated at an especially rapid rate for unexpected fearful faces (associated with activity in the right inferior frontal gyrus). Hence, these findings demonstrate a novel interaction between emotion and expectation during bCFS, driven by a unique influence of surprising fearful stimuli that expedites evidence accumulation in a fronto-occipital network.
De-confounding the neural constitution of phenomenal consciousness from attention, report and memory
Publisher: John Benjamins Publishing Company
Date: 2015
How much can we differentiate at a brief glance: Revealing the truer limit in conscious contents through the Massive Report Paradigm (MRP)
Publisher: Center for Open Science
Date: 05-04-2022
Abstract: Upon a brief glance, how well can we differentiate what we see from what we do not? Previous studies answered this question as “poorly”. This is in stark contrast with our everyday experience. Here, we consider the possibility that previous restriction in stimulus variability and response alternatives reduced what participants could express from what they consciously experienced. We introduce a novel Massive Report paradigm that probes the ability to differentiate what we see from what we do not. In each trial, participants viewed a natural scene image and judged whether a small image patch was a part of the original image. To examine the limit of discriminability, we also included subtler changes in the image as modification of objects. Neither the images nor patches were repeated per participant. Our results showed that participants were highly accurate (accuracy & 80%) in differentiating patches from the viewed images from patches that are not present. Additionally, the differentiation between original and modified objects was influenced by object sizes and/or the congruence between objects and the scene gists. Our Massive Report paradigm opens a door to quantitatively measure the limit of immense informativeness of a moment of consciousness.
A relational approach to consciousness: categories of level and contents of consciousness
Publisher: Oxford University Press (OUP)
Date: 10-2021
DOI: 10.1093/NC/NIAB034
Abstract: Characterizing consciousness in and of itself is notoriously difficult. Here, we propose an alternative approach to characterize, and eventually define, consciousness through exhaustive descriptions of consciousness’ relationships to all other consciousness. This approach is founded in category theory. Indeed, category theory can prove that two objects A and B in a category can be equivalent if and only if all the relationships that A holds with others in the category are the same as those of B this proof is called the Yoneda lemma. To introduce the Yoneda lemma, we gradually introduce key concepts of category theory to consciousness researchers. Along the way, we propose several possible definitions of categories of consciousness, both in terms of level and contents, through the usage of simple ex les. We propose to use the categorical structure of consciousness as a gold standard to formalize empirical research (e.g. color qualia structure at fovea and periphery) and, especially, the empirical testing of theories of consciousness.
The Relationship Between Consciousness and Attention
Publisher: Elsevier
Date: 2009
From Intermodulation Components to Perception and Cognition- a Review
Publisher: Center for Open Science
Date: 2019
Abstract: Perception results from complex interactions among sensory and cognitive processes across hierarchical levels in the brain. Intermodulation (IM) components, used in frequency tagging neuroimaging designs, have emerged as a promising direct measure of such neural interactions. IMs have initially been used in electroencephalography (EEG) to investigate low-level visual processing. In a more recent trend, IMs in EEG and other neuroimaging methods are being used to shed light on mechanisms of mid- and high-level perceptual processes, including the involvement of cognitive functions such as attention and expectation. Here, we provide an account of various mechanisms that may give rise to IMs in neuroimaging data, and what these IMs may look like. We discuss methodologies that can be implemented for different uses of IMs and we demonstrate how IMs can provide insights into the existence, the degree and the type of neural integration mechanisms at hand. We then review a range of recent studies exploiting IMs in perception research, placing an emphasis on high-level visual processes. We conclude by suggesting future directions that can enhance the benefits of IM-methodology in perception research.
Wandering minds, sleepy brains: lapses of attention and local sleep in wakefulness
Publisher: Research Square Platform LLC
Date: 17-08-2020
DOI: 10.21203/RS.3.RS-50949/V1
Abstract: Attentional lapses are ubiquitous and can negatively impact performance. They correlate with mind wandering, or thoughts that are unrelated to ongoing tasks and environmental demands. In other cases, the stream of consciousness itself comes to a halt and the mind goes blank. What happens in the brain that leads to these mental states? To understand the neural mechanisms underlying attentional lapses, we cross-analyzed the behavior, subjective experience and neural activity of healthy participants performing a task. Random interruptions prompted participants to indicate whether they were task-focused, mind-wandering or mind-blanking. High-density electroencephalography revealed the occurrence of spatially and temporally localized sleep-like patterns of neural activity. This “local sleep” accompanied behavioral markers of lapses and preceded reports of mind wandering and mind blanking. Furthermore, the location of local sleep distinguished sluggish versus impulsive behaviors, mind wandering versus mind blanking. Despite contrasting cognitive profiles, attentional lapses could share a common physiological origin: the appearance of local islets of sleep within the awake brain.
Towards blinded classification of loss of consciousness: distinguishing wakefulness from general anesthesia and sleep in flies using a massive library of univariate time series analyses
Publisher: Center for Open Science
Date: 13-06-2023
Abstract: The neural mechanisms of consciousness remain elusive. Previous studies on both human and non-human animals, through manipulation of level of conscious arousal, have reported that specific time-series features correlate with level of consciousness, such as spectral power in certain frequency bands. However, such features often lack principled, theoretical justifications as to why they should be related with level of consciousness. This raises two significant issues: firstly, many other types of times-series features which could also reflect conscious level have been ignored due to researcher biases towards specific analyses and secondly, it is unclear how to interpret identified features to understand the neural activity underlying consciousness, especially when they are identified from recordings which summate activity across large areas such as electroencephalographic recordings. To address the first concern, here we propose a new approach: in the absence of any theoretical priors, we should be maximally agnostic and treat as many known features as feasible as equally promising candidates. To apply this approach we use highly comparative time-series analysis (hctsa), a toolbox which provides over 7,700 different univariate time-series features originating from different research fields. To address the second issue, we employ hctsa to high-quality neural recordings from a relatively simple brain, the fly brain (Drosophila melanogaster), extracting features from local field potentials during wakefulness, general anesthesia and sleep. For each feature, we constructed a classifier for discriminating wakefulness and anesthesia in a discovery group of flies (N = 13). In this registered report, we will assess their performance on a blinded evaluation group of flies (N = 12 for graded levels of anesthesia, N = 18 for single dose anesthesia, and N = 19 for sleep). While the full details of the experimental methods are unknown to the data analysis team at the time of submission of this Stage 1 manuscript, they will be reported upon in-principle acceptance. Pilot results indicate that the performance of only a small subset of features (up to 561, depending on recording location) successfully generalizes to an independent dataset (N = 2). Features which successfully generalize can be fruitful avenues to explore towards robust discoveries of the neural correlates of consciousness.
Are we underestimating the richness of visual experience?
Publisher: Oxford University Press (OUP)
Date: 2017
DOI: 10.1093/NC/NIW023
The Role of Risk Aversion in Non-Conscious Decision Making
Publisher: Frontiers Media SA
Date: 2012
Emergence of integrated information at macro timescales in real neural recordings
Publisher: Cold Spring Harbor Laboratory
Date: 08-03-2022
DOI: 10.1101/2022.03.07.483390
Abstract: How a system generates conscious experience remains an elusive question. One approach towards answering this is to consider the information available in the system from the perspective of the system itself. Integrated information theory (IIT) proposes a measure to capture this, integrated information (Φ). While Φ can be computed at any spatiotemporal scale, IIT posits that it be applied at the scale at which the measure is maximised. Importantly, Φ should emerge to be maximal not at the smallest spatiotemporal scale, but at some macro scale where system elements or timesteps are grouped into larger elements or timesteps. Emergence in this sense has been demonstrated in artificial binary systems, but it remains unclear whether it occurs in real neural recordings which are generally continuous and noisy. Here we first utilise a computational model to confirm that Φ becomes maximal at the temporal scales underlying its generative mechanisms. Second, we search for emergence in local field potentials from the fly brain recorded during wakefulness and anaesthesia, finding that normalised Φ (wake/anaesthesia), but not raw Φ values, peaks at 5 ms. Lastly, we extend our model to investigate why raw Φ values themselves did not peak. This work extends the application of Φ to simple artificial systems consisting of logic gates towards searching for emergence of a macro spatiotemporal scale in real neural systems.
From intermodulation components to visual perception and cognition-a review
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.NEUROIMAGE.2019.06.008
Abstract: Perception results from complex interactions among sensory and cognitive processes across hierarchical levels in the brain. Intermodulation (IM) components, used in frequency tagging neuroimaging designs, have emerged as a promising direct measure of such neural interactions. IMs have initially been used in electroencephalography (EEG) to investigate low-level visual processing. In a more recent trend, IMs in EEG and other neuroimaging methods are being used to shed light on mechanisms of mid- and high-level perceptual processes, including the involvement of cognitive functions such as attention and expectation. Here, we provide an account of various mechanisms that may give rise to IMs in neuroimaging data, and what these IMs may look like. We discuss methodologies that can be implemented for different uses of IMs and we demonstrate how IMs can provide insights into the existence, the degree and the type of neural integration mechanisms at hand. We then review a range of recent studies exploiting IMs in visual perception research, placing an emphasis on high-level vision and the influence of awareness and cognition on visual processing. We conclude by suggesting future directions that can enhance the benefits of IM-methodology in perception research.
When Mind and Body Align: Examining the Role of Cross-Modal Congruency in Conscious Representations of Happy Facial Expressions
Publisher: Center for Open Science
Date: 28-07-2023
Abstract: This study aimed to investigate the impact of congruence between facial mimicry and observed facial expressions on the stabilization of conscious representations of facial expressions. Building upon previous research, our specific hypothesis focused on a congruence effect between proprioceptive/sensorimotor signals and visual stimuli regarding the stabilization of awareness for happy facial expressions during a binocular rivalry task. Participants performed a binocular rivalry task with neutral and happy faces presented in rivalry. Facial mimicry was manipulated by either facilitating facial muscle contraction using a chopstick or allowing free engagement in facial mimicry. Cumulative time (CT) was used as a measure of content stabilization in awareness. Results showed that the manipulation of facial mimicry influenced the CT for happy faces, increasing their stability compared to unrestricted mimicry conditions. The findings suggest that congruence between mimicry and observed facial expressions plays a crucial role in stabilizing content in awareness. These findings contribute to the understanding of how congruent sensorimotor information shapes conscious visual perception of facial expressions. They align with models of embodied cognition, emphasizing the integration of proprioceptive signals in facial expressions, which significantly biases visual conscious experience.
Does the mind wander when the brain takes a break? Local sleep in wakefulness, attentional lapses and mind-wandering
Publisher: Center for Open Science
Date: 20-06-2019
Abstract: Sleep has been classically described as an all-or-nothing global phenomenon. However, recent research suggests that this view requires tempering. Invasive and non-invasive recordings in animals and humans show that neural activity typically associated with sleep can locally occur during wakefulness. Although local sleep is defined neuronally, it has been associated with impaired performance during cognitive tasks. Comparatively, the phenomenology of local sleep (i.e. what it feels like when your brain is partially asleep) has been less explored. Taking into account the literature on the neuronal and behavioural profile of local sleep intrusions in wakefulness, we propose that occurrences of local sleep could represent the neural mechanism underlying many attentional lapses. In particular, we argue that a unique physiological event such as local sleep could account for a ersity of behavioural outcomes from sluggish to impulsive responses. We further propose that local sleep intrusions could impact in iduals’ subjective experience. Specifically, we propose that the timing and anatomical sources of local sleep intrusions could be responsible for both the behavioural consequences and subjective content of attentional lapses and may underlie the difference between subjective experiences such as mind wandering and mind blanking. Our framework aims to build a parallel between spontaneous experiences in sleep and wakefulness by integrating evidence across neuronal, behavioural and experiential levels. We use the ex le of attention deficit hyperactivity disorder (ADHD) to illustrate how local sleep could explain complex cognitive profiles which include inattention, impulsivity, mind-wandering and mind-blanking.
Neural and computational processes of accelerated perceptual awareness and decisions: A 7T fMRI Study
Publisher: Cold Spring Harbor Laboratory
Date: 23-07-2021
DOI: 10.1101/2021.07.22.453451
Abstract: Rapidly detecting salient information in our environments is critical for survival. Visual processing in subcortical areas like the pulvinar and amygdala have been shown to facilitate unconscious processing of salient stimuli. It is unknown, however, if and how these areas might interact with cortical networks to facilitate faster conscious perception of salient stimuli. Here we investigated these neural processes using 7T functional Magnetic Resonance Imaging (fMRI) in concert with computational modelling while participants (n = 32) engaged in a breaking continuous flash suppression paradigm (bCFS) in which fearful and neutral faces are initially suppressed from conscious perception but then eventually “breakthrough” into awareness. We found that participants reported faster breakthrough times for fearful faces compared to neutral faces. Drift-diffusion modelling suggested that perceptual evidence was accumulated at a faster rate for fearful faces compared to neutral faces. For both neutral and fearful faces, faster response times coincided with greater activity in the amygdala (specifically within its subregions, including superficial, basolateral and amygdalo-striatal transition area) and the insula. Faster rates of evidence accumulation coincided with greater activity in frontoparietal regions and the occipital lobe, as well as the amygdala. Overall, our findings suggest that hastened perceptual awareness of salient stimuli recruits the amygdala and, more specifically, is driven by accelerated evidence accumulation in fronto-parietal and visual areas. In sum, we have uncovered and mapped distinct neural computations that accelerate perceptual awareness of visually suppressed faces.
Are Color Experiences the Same across the Visual Field?
Publisher: MIT Press
Date: 2023
DOI: 10.1162/JOCN_A_01962
Abstract: It seems obvious to laypeople that neurotypical humans experience color equivalently across their entire visual field. To some neuroscientists, psychologists, and philosophers, though, this claim has been met with skepticism, as neurophysiological evidence indicates the mechanisms that support color perception degrade with eccentricity. However, the argument that this entails altered color experience in peripheral vision is not universally accepted. Here, we address whether color experience is essentially equivalent between central and peripheral vision. To assess this, we will obtain similarity relationships between color experiences across the visual field using both online and laboratory-based far-field displays, while removing the confounds of saccades, memory, and expectation about color experiences. Our experiment was designed to provide clear evidence that would favor either unchanged or altered color experience relationships in the periphery. Our results are consistent with lay people's phenomenological reports: Color experiences, as probed by similarity relationships in central vision and the far field (60°), are equivalent when elicited by large stimuli. These findings challenge the widespread view in philosophy and cognitive science that peripheral color experiences are illusory, and are discussed in the context of their related neurophysiological, psychophysical, and philosophical literature.
Semantic Wavelet-Induced Frequency-Tagging (SWIFT) Periodically Activates Category Selective Areas While Steadily Activating Early Visual Areas
Publisher: Public Library of Science (PLoS)
Date: 21-12-2015
Does the Mind Wander When the Brain Takes a Break? Local Sleep in Wakefulness, Attentional Lapses and Mind-Wandering
Publisher: Frontiers Media SA
Date: 13-09-2019
Conscious perception of flickering stimuli in binocular rivalry and continuous flash suppression is not affected by tACS-induced SSR modulation
Publisher: Cold Spring Harbor Laboratory
Date: 10-10-2019
DOI: 10.1101/788950
Abstract: The content of conscious perception is known to correlate with steady-state responses (SSRs), yet their causal relationship remains unclear. Can we manipulate conscious perception by directly interfering with SSRs through transcranial alternating current stimulation (tACS)? Here, we directly addressed this question in three experiments involving binocular rivalry and continuous flash suppression (CFS). Specifically, while participants (N=24) viewed either binocular rivalry or tried to detect stimuli masked by CFS, we applied sham or real tACS across parieto-occipital cortex at either the same or a different frequency and phase as an SSR eliciting flicker stimulus. We found that tACS did not differentially affect conscious perception in the forms of predominance, CFS detection accuracy, reaction time, or metacognitive sensitivity, confirmed by Bayesian statistics. We conclude that tACS application at frequencies of stimulus-induced SSRs does not have perceptual effects and that SSRs may be epiphenomenal to conscious perception.
The Relationship Between Consciousness and Top-Down Attention
Publisher: Elsevier
Date: 2016
Abnormal social reward processing in autism as indexed by pupillary responses to happy faces
Publisher: Springer Science and Business Media LLC
Date: 07-06-2012
Abstract: In iduals with Autism Spectrum Disorders (ASD) typically show impaired eye contact during social interactions. From a young age, they look less at faces than typically developing (TD) children and tend to avoid direct gaze. However, the reason for this behavior remains controversial ASD children might avoid eye contact because they perceive the eyes as aversive or because they do not find social engagement through mutual gaze rewarding. We monitored pupillary diameter as a measure of autonomic response in children with ASD ( n = 20, mean age = 12.4) and TD controls ( n = 18, mean age = 13.7) while they looked at faces displaying different emotions. Each face displayed happy, fearful, angry or neutral emotions with the gaze either directed to or averted from the subjects. Overall, children with ASD and TD controls showed similar pupillary responses however, they differed significantly in their sensitivity to gaze direction for happy faces. Specifically, pupillary diameter increased among TD children when viewing happy faces with direct gaze as compared to those with averted gaze, whereas children with ASD did not show such sensitivity to gaze direction. We found no group differences in fixation that could explain the differential pupillary responses. There was no effect of gaze direction on pupil diameter for negative affect or neutral faces among either the TD or ASD group. We interpret the increased pupillary diameter to happy faces with direct gaze in TD children to reflect the intrinsic reward value of a smiling face looking directly at an in idual. The lack of this effect in children with ASD is consistent with the hypothesis that in iduals with ASD may have reduced sensitivity to the reward value of social stimuli.
Conscious access in the near absence of attention: critical extensions on the dual-task paradigm
Publisher: The Royal Society
Date: 30-07-2018
Abstract: Whether conscious perception requires attention remains a topic of intense debate. While certain complex stimuli such as faces and animals can be discriminated outside the focus of spatial attention, many simpler stimuli cannot. Because such evidence was obtained in dual-task paradigms involving no measure of subjective insight, it remains unclear whether accurate discrimination of unattended complex stimuli is the product of automatic, unconscious processing, as in blindsight, or is accessible to consciousness. Furthermore, these paradigms typically require extensive training over many hours, bringing into question whether this phenomenon can be achieved in naive subjects. We developed a novel dual-task paradigm incorporating confidence ratings to calculate metacognition and adaptive staircase procedures to reduce training. With minimal training, subjects were able to discriminate face-gender in the near absence of top–down attentional lification, while also displaying above-chance metacognitive accuracy. By contrast, the discrimination of simple coloured discs was significantly impaired and metacognitive accuracy dropped to chance-level, even in a partial-report condition. In a final experiment, we used blended face/disc stimuli and confirmed that face-gender but not colour orientation can be discriminated in the dual task. Our results show direct evidence for metacognitive conscious access in the near absence of attention for complex, but not simple, stimuli. This article is part of the theme issue ‘Perceptual consciousness and cognitive access'.
Growing Evidence for Separate Neural Mechanisms for Attention and Consciousness
Publisher: Center for Open Science
Date: 27-06-2020
Abstract: Our conscious experience of the world seems to go in lockstep with our attentional focus: we tend to see, hear, taste and feel what we attend to, and vice versa. This tight coupling between attention and consciousness has given rise to the idea that these two phenomena are in isible. In the late 1950s, the honoree of this special issue, Charles Eriksen, was among a small group of early pioneers that sought to investigate whether a transient increase in overall level of attention (alertness) in response to a noxious stimulus can be decoupled from conscious perception using experimental techniques. Recent years saw a similar debate regarding whether attention and consciousness are two dissociable processes. Initial evidence that attention and consciousness are two separate processes primarily rested on behavioral data. However, the past couple of years witnessed an explosion of studies aimed at testing this conjecture using neuroscientific techniques. Here we provide an overview of these and related empirical studies on the distinction between the neuronal correlates of attention and consciousness, and detail how advancements in theory and technology can bring about a more detailed understanding of the two. We argue that the most promising approach will combine ever evolving neurophysiological and interventionist tools with quantitative, empirically testable theories of consciousness that are grounded in a mathematically formalized understanding of phenomenology.
Category theoretic approach towards the definition of consciousness
Publisher: Open Science Framework
Date: 2019
Are the Neural Correlates of Consciousness in the Front or in the Back of the Cerebral Cortex? Clinical and Neuroimaging Evidence
Publisher: Society for Neuroscience
Date: 04-10-2017
DOI: 10.1523/JNEUROSCI.3218-16.2017
Abstract: The role of the frontal cortex in consciousness remains a matter of debate. In this Perspective, we will critically review the clinical and neuroimaging evidence for the involvement of the front versus the back of the cortex in specifying conscious contents and discuss promising research avenues. Dual Perspectives Companion Paper: Should a Few Null Findings Falsify Prefrontal Theories of Conscious Perception?, by Brian Odegaard, Robert T. Knight, and Hakwan Lau
Steady state evoked potential (SSEP) responses in the primary and secondary somatosensory cortices of anesthetized cats: nonlinearity characterized by harmonic and intermodulation frequencies
Publisher: Cold Spring Harbor Laboratory
Date: 22-09-2020
DOI: 10.1101/2020.09.22.307652
Abstract: When presented with an oscillatory sensory input at a particular frequency, F [Hz], neural systems respond with the corresponding frequency, f [Hz], and its multiples. When the input includes two frequencies ( F1 and F2 ) and they are nonlinearly integrated in the system, responses at intermodulation frequencies (i.e., n1 * f1 + n2 * f2 [Hz], where n1 and n2 are non-zero integers) emerge. Utilizing these properties, the steady state evoked potential (SSEP) paradigm allows us to characterize linear and nonlinear neural computation performed in cortical neurocircuitry. Here, we analyzed the steady state evoked local field potentials (LFPs) recorded from the primary (S1) and secondary (S2) somatosensory cortex of anesthetized (ketamine-xylazine) cats while we presented slow ( F1 =23Hz) and fast ( F2 =200Hz) somatosensory vibration to the contralateral paw pads and digits. Over 9 experimental sessions, we recorded LFPs from N =1620 and N =1008 bipolar-referenced sites in S1 and S2 using electrode arrays. Power spectral analyses revealed strong responses at 1) the fundamental ( f1 , f2 ), 2) its harmonic, 3) the intermodulation frequencies, and 4) broadband frequencies (50-150Hz). To compare the computational architecture in S1 and S2, we employed simple computational modeling. Our modeling results necessitate nonlinear computation to explain SSEP in S2 more than S1. Combined with our current analysis of LFPs, our paradigm offers a rare opportunity to constrain the computational architecture of hierarchical organization of S1 and S2 and to reveal how a large-scale SSEP can emerge from local neural population activities.
Growing evidence for separate neural mechanisms for attention and consciousness
Publisher: Springer Science and Business Media LLC
Date: 09-10-2020
Reading the mind's eye: Decoding category information during mental imagery
Publisher: Elsevier BV
Date: 04-2010
When do parts form wholes? Integrated information as the restriction on mereological composition
Publisher: Center for Open Science
Date: 22-04-2023
Abstract: Under what conditions are material objects, such as particles, parts of a whole object? This is the composition question and is a longstanding open question in philosophy. Existing attempts to specify a non-trivial restriction on composition tend to be vague and face serious counterex les. Consequently, two extreme answers have become mainstream: composition (the forming of a whole by its parts) happens under no or all conditions. In this paper, we provide a self-contained introduction to the integrated information theory of consciousness (IIT). We show that IIT specifies a non-trivial restriction on composition: composition happens when integrated information is maximized. We compare the IIT-restriction to existing proposals and argue that the IIT-restriction has significant advantages, especially in response to the problems of vagueness and counterex les. An appendix provides an introduction to calculating parts and wholes with a simple system.
Author response: Attention periodically samples competing stimuli during binocular rivalry
Publisher: eLife Sciences Publications, Ltd
Date: 05-11-2018
Geometry of Information Integration
Publisher: Springer International Publishing
Date: 2018
Third-eye Rivalry
Publisher: Center for Open Science
Date: 12-09-2019
Abstract: We showcase an optical phenomenon that we call “Third-eye Rivalry”. The effect is most easily induced by viewing one’s own reflection in a mirror. Using the pupil of the opposing eye as a fixation target, people can easily cross their eyes in free-fusion to experience vivid rivalry. The resulting percept is of a prominent central “third” eye and two peripheral faces rivalling for perceptual dominance. We illustrate the process of achieving third-eye rivalry and discuss historical connotations of the third eye in scientific and mystical contexts.
Beyond traditional sleep scoring: Massive feature extraction and data-driven clustering of sleep time series
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.SLEEP.2022.06.013
Abstract: The widely used guidelines for sleep staging were developed for the visual inspection of electrophysiological recordings by the human eye. As such, these rules reflect a limited range of features in these data and are therefore restricted in accurately capturing the physiological changes associated with sleep. Here we present a novel analysis framework that extensively characterizes sleep dynamics using over 7700 time-series features from the hctsa software. We used clustering to categorize sleep epochs based on the similarity of their time-series features, without relying on established scoring conventions. The resulting sleep structure overlapped substantially with that defined by visual scoring. However, we also observed discrepancies between our approach and traditional scoring. This ergence principally stemmed from the extensive characterization by hctsa features, which captured distinctive time-series properties within the traditionally defined sleep stages that are overlooked with visual scoring. Lastly, we report time-series features that are highly discriminative of stages. Our framework lays the groundwork for a data-driven exploration of sleep sub-stages and has significant potential to identify new signatures of sleep disorders and conscious sleep states.
The Dream Catcher experiment: blinded analyses failed to detect markers of dreaming consciousness in EEG spectral power
Publisher: Oxford University Press (OUP)
Date: 2020
DOI: 10.1093/NC/NIAA006
Abstract: The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the first time in a step-wise and simplified form, capturing its core idea. The Dream Catcher experiment involved a Data Team, which measured participants’ brain activity during sleep and collected dream reports, and a blinded Analysis Team, which was challenged to predict, based solely on brain measurements, whether or not a participant had a dream experience. Using a serial-awakening paradigm, the Data Team prepared 54 1-min polysomnograms of non-rapid eye movement sleep—27 of dreamful sleep and 27 of dreamless sleep (three of each condition from each of the nine participants)—redacting from them all associated participant and dream information. The Analysis Team attempted to classify each recording as either dreamless or dreamful using an unsupervised machine learning classifier, based on hypothesis-driven, extracted features of electroencephalography (EEG) spectral power and electrode location. The procedure was repeated over five iterations with a gradual removal of blindness. At no level of blindness did the Analysis Team perform significantly better than chance, suggesting that EEG spectral power could not be utilized to detect signatures specific to phenomenal consciousness in these data. This study marks the first step towards realizing the Dream Catcher test in practice.
Author response: The SSVEP tracks attention, not consciousness, during perceptual filling-in
Publisher: eLife Sciences Publications, Ltd
Date: 31-10-2020
INs and OUTs of Faces in Consciousness: A study of the temporal evolution of consciousness of faces during binocular rivalry
Publisher: Center for Open Science
Date: 26-01-2023
Abstract: Contents of consciousness change over time. However, the study of dynamics in consciousness has been largely neglected. Aru and Bachmann have recently brought to the attention of scientists dealing with consciousness the relevance of making inquiries about its temporal evolution. Importantly, they also pointed out several experimental questions as guidelines for researchers interested in studying the temporal evolution of consciousness, including the phases of formation and dissolution of content. They also suggested that these two phases could be characterized by asymmetric inertia. The main objective of the present investigation was to implement and validate a method to approximate the dynamics of these two phases. To this aim, we tested the time course of content transitions during a binocular rivalry task using face stimuli and asked participants to map their subjective experience of transitions from one content to the other through a joystick. We then computed metrics of joystick velocity linked to content transitions as proxies of the formation and dissolution phases. We found a general phase effect such that the formation phase was slower than the dissolution phase. Furthermore, we observed an effect specific to happy facial expressions, such that their contents were slower to form and dissolve than that of neutral expressions. We further propose to include a third phase of stabilization of conscious content between formation and dissolution. To conclude, the method and the metrics we propose seem to provide a good proxy to study the temporal evolution of consciousness.
The Effect of Common Signals on Power, Coherence and Granger Causality: Theoretical Review, Simulations, and Empirical Analysis of Fruit Fly LFPs Data
Publisher: Frontiers Media SA
Date: 25-07-2018
Intracranial markers of conscious face perception in humans
Publisher: Elsevier BV
Date: 11-2017
A multiple-response frequency-tagging paradigm measures graded changes in consciousness during perceptual filling-in
Publisher: Oxford University Press (OUP)
Date: 2020
DOI: 10.1093/NC/NIAA002
Abstract: Perceptual filling-in (PFI) occurs when a physically present visual target disappears from conscious perception, with its location filled-in by the surrounding visual background. These perceptual changes are complete, near instantaneous, and can occur for multiple separate locations simultaneously. Here, we show that contrasting neural activity during the presence or absence of multi-target PFI can complement other findings from multistable phenomena to reveal the neural correlates of consciousness (NCC). We presented four peripheral targets over a background dynamically updating at 20 Hz. While participants reported on target disappearances/reappearances via button press/release, we tracked neural activity entrained by the background during PFI using steady-state visually evoked potentials (SSVEPs) recorded in the electroencephalogram. We found background SSVEPs closely correlated with subjective report, and increased with an increasing amount of PFI. Unexpectedly, we found that as the number of filled-in targets increased, the duration of target disappearances also increased, suggesting that facilitatory interactions exist between targets in separate visual quadrants. We also found distinct spatiotemporal correlates for the background SSVEP harmonics. Prior to genuine PFI, the response at the second harmonic (40 Hz) increased before the first (20 Hz), which we tentatively link to an attentional effect, while no such difference between harmonics was observed for physically removed stimuli. These results demonstrate that PFI can be used to study multi-object perceptual suppression when frequency-tagging the background of a visual display, and because there are distinct neural correlates for endogenously and exogenously induced changes in consciousness, that it is ideally suited to study the NCC.
DREAM: A Dream EEG and Mentation database
Publisher: Center for Open Science
Date: 16-05-2023
Abstract: Electroencephalography (EEG) studies of dreaming are an integral paradigm in the study of neurocognitive processes of human sleep and consciousness, but they are limited by the number of observations that can be collected per study. Dream studies also involve substantial methodological and conceptual variability which poses problems for the integration of results. To address these issues, we present the DREAM database—an expanding collection of standardized datasets on human sleep EEG combined with dream report data—with an initial release of 18 datasets, totaling 2331 data points. Each datum consists, at minimum, of sleep electroencephalography (≥20 s, ≥100 Hz, ≥2 electrodes) up to the time of waking and a standardized dream report classification of the subject’s reported sleep experience. This database will provide access to a larger pool of data than any single research group can collect and increase the statistical power of studies focusing on the neural correlates of dreaming. It will also provide useful criteria for methodological choices in future dream laboratory research projects.
Attention periodically samples competing stimuli during binocular rivalry
Publisher: Cold Spring Harbor Laboratory
Date: 25-01-2018
DOI: 10.1101/253740
Abstract: The attentional s ling hypothesis suggests that attention rhythmically enhances sensory processing when attending to a single (~8 Hz), or multiple (~4 Hz) objects. Here we investigated using binocular rivalry whether attention s les sensory representations that are not part of the conscious percept, during competition for perceptual dominance. When crossmodally cued toward a conscious image, subsequent changes in consciousness occurred at ~8 Hz, consistent with rates of un ided attentional s ling. However, when attention was cued toward the suppressed image, changes in consciousness slowed to ~3.5 Hz, indicating the ision of attention away from the conscious visual image. In the electroencephalogram, we found that at 3.5 and 8 Hz, the strength of inter-trial phase coherence over fronto-temporal and parieto-occipital regions correlated with behavioral measures of changes in perception. When cues were not task-relevant, these effects disappeared, confirming that perceptual changes were dependent upon the allocation of attention, and that attention can flexibly s le away from a conscious image in a task-dependent manner.
Mathematics and the Brain: A Category Theoretical Approach to Go Beyond the Neural Correlates of Consciousness
Publisher: MDPI AG
Date: 17-12-2019
DOI: 10.3390/E21121234
Abstract: Consciousness is a central issue in neuroscience, however, we still lack a formal framework that can address the nature of the relationship between consciousness and its physical substrates. In this review, we provide a novel mathematical framework of category theory (CT), in which we can define and study the sameness between different domains of phenomena such as consciousness and its neural substrates. CT was designed and developed to deal with the relationships between various domains of phenomena. We introduce three concepts of CT which include (i) category (ii) inclusion functor and expansion functor and, most importantly, (iii) natural transformation between the functors. Each of these mathematical concepts is related to specific features in the neural correlates of consciousness (NCC). In this novel framework, we will examine two of the major theories of consciousness, integrated information theory (IIT) of consciousness and temporospatial theory of consciousness (TTC). We conclude that CT, especially the application of the notion of natural transformation, highlights that we need to go beyond NCC and unravels questions that need to be addressed by any future neuroscientific theory of consciousness.
Lifting the veil: Altered visual perception in derealisation
Publisher: Center for Open Science
Date: 14-06-2023
Abstract: During an acute episode of depersonalisation/derealisation (DP/DR), people report a complex and idiosyncratic change in their perceptual experience. Specifically, derealisation describes the experience of detachment from the external world and altered visual perception in which the surroundings look faded, foggy or dream-like.Whilst some have argued that there may not be genuine perceptual changes in derealisation, this proposal is yet to be tested empirically. Thus, we set out to investigate the potential perceptual changes in derealisation. In this Registered Report, we propose to conduct a series of online experiments to reveal the impact of DP/DR on how people interact with visual stimuli and to shed light on the relationship between faded perceptual experiences and an altered sense of reality.
General anesthesia reduces complexity and temporal asymmetry of the informational structures derived from neural recordings in Drosophila
Publisher: American Physical Society (APS)
Date: 22-05-2020
Introduction to research topic: attention and consciousness in different senses
Publisher: Frontiers Media SA
Date: 2013
Measuring graded changes in consciousness through multi-target filling-in
Publisher: Cold Spring Harbor Laboratory
Date: 18-12-2018
DOI: 10.1101/499517
Abstract: Perceptual filling-in (PFI) occurs when a physically-present visual target disappears from conscious perception, with its location filled in by the surrounding visual background. Compared to other visual illusions, these perceptual changes are crisp and simple, and can occur for multiple spatially-separated targets simultaneously. Contrasting neural activity during the presence or absence of PFI may complement other multistable phenomena to reveal the neural correlates of consciousness (NCC). We presented four peripheral targets over a background dynamically updating at 20 Hz. While participants reported on target disappearances/reappearances via button press/release, we tracked neural activity entrained by the background during PFI using steady-state visually evoked potentials (SSVEPs) recorded in the electroencephalogram. We found background SSVEPs closely correlated with subjective report, and increased with an increasing amount of PFI. Unexpectedly, we found that as the number of filled-in targets increased, the duration of target disappearances also increased, suggesting facilitatory interactions exist between targets in separate visual quadrants. We also found distinct spatiotemporal correlates for the background SSVEP harmonics. Prior to genuine PFI, the response at the second harmonic (40 Hz) increased before the first (20 Hz), which we tentatively link to an attentional effect. There was no difference between harmonics for physically removed stimuli. These results demonstrate that PFI can be used to study multi-object perceptual suppression when frequency-tagging the background of a visual display, and because there are distinct neural correlates for endogenously and exogenously induced changes in consciousness, that it is ideally suited to study the NCC. Perceptual filling-in (PFI) has distinct advantages for investigating the neural correlates of consciousness. Participants can accurately report graded changes in consciousness using four simultaneous buttons. Frequency-tagging of visual background information tracks changes in visual perception. Spatiotemporal EEG responses differentiate PFI from phenomenally matched physical disappearances.
The Scope and Limits of Top-Down Attention in Unconscious Visual Processing
Publisher: Elsevier BV
Date: 12-2006
DOI: 10.1016/J.CUB.2006.10.001
Abstract: Attentional selection plays a critical role in conscious perception. When attention is erted, even salient stimuli fail to reach visual awareness. Attention can be voluntarily directed to a spatial location or a visual feature for facilitating the processing of information relevant to current goals. In everyday situations, attention and awareness are tightly coupled. This has led some to suggest that attention and awareness might be based on a common neural foundation, whereas others argue that they are mediated by distinct mechanisms. A body of evidence shows that visual stimuli can be processed at multiple stages of the visual-processing streams without evoking visual awareness. To illuminate the relationship between visual attention and conscious perception, we investigated whether top-down attention can target and modulate the neural representations of unconsciously processed visual stimuli. Our experiments show that spatial attention can target only consciously perceived stimuli, whereas feature-based attention can modulate the processing of invisible stimuli. The attentional modulation of unconscious signals implies that attention and awareness can be dissociated, challenging a simplistic view of the boundary between conscious and unconscious visual processing.
Metacognitive Accuracy Improves With the Perceptual Learning of a Low- but Not High-Level Face Property
Publisher: Frontiers Media SA
Date: 24-07-2019
Intact rapid detection of fearful faces in the absence of the amygdala
Publisher: Springer Science and Business Media LLC
Date: 30-08-2009
DOI: 10.1038/NN.2380
Deep Brain Stimulation for Parkinson’s disease changes perception in the Rubber Hand Illusion
Publisher: Springer Science and Business Media LLC
Date: 14-09-2018
DOI: 10.1038/S41598-018-31867-8
Abstract: Parkinson’s disease (PD) alters cortico-basal ganglia-thalamic circuitry and susceptibility to an illusion of bodily awareness, the Rubber Hand Illusion (RHI). Bodily awareness is thought to result from multisensory integration in a predominantly cortical network the role of subcortical connections is unknown. We studied the effect of modulating cortico-subcortical circuitry on multisensory integration for bodily awareness in 24 PD patients treated with subthalamic nucleus (STN) deep brain stimulation (DBS), in comparison to 21 healthy volunteers, using the RHI experiment. Typically, synchronous visuo-tactile cues induce a false perception of touch on the rubber hand as if it were the subject’s hand, whereas asynchronous visuo-tactile cues do not. However, we found that in the asynchronous condition, patients in the off-stimulation state did not reject the RHI as strongly as healthy controls patients’ rejection of the RHI strengthened when STN-DBS was switched on, although it remained weaker than that of controls. Patients in the off-stimulation state also misjudged the position of their hand, indicating it to be closer to the rubber hand than controls. However, STN-DBS did not affect proprioceptive judgements or subsequent arm movements altered by the perceptual effects of the illusion. Our findings support the idea that the STN and subcortical connections have a key role in multisensory integration for bodily awareness. Decision-making in multisensory bodily illusions is discussed.
Large Capacity of Conscious Access for Incidental Memories in Natural Scenes
Publisher: SAGE Publications
Date: 20-08-2016
Abstract: When searching a crowd, people can detect a target face only by direct fixation and attention. Once the target is found, it is consciously experienced and remembered, but what is the perceptual fate of the fixated nontarget faces? Whereas introspection suggests that one may remember nontargets, previous studies have proposed that almost no memory should be retained. Using a gaze-contingent paradigm, we asked subjects to visually search for a target face within a crowded natural scene and then tested their memory for nontarget faces, as well as their confidence in those memories. Subjects remembered up to seven fixated, nontarget faces with more than 70% accuracy. Memory accuracy was correlated with trial-by-trial confidence ratings, which implies that the memory was consciously maintained and accessed. When the search scene was inverted, no more than three nontarget faces were remembered. These findings imply that incidental memory for faces, such as those recalled by eyewitnesses, is more reliable than is usually assumed.
Attention and consciousness: two distinct brain processes
Publisher: Elsevier BV
Date: 2007
DOI: 10.1016/J.TICS.2006.10.012
Abstract: The close relationship between attention and consciousness has led many scholars to conflate these processes. This article summarizes psychophysical evidence, arguing that top-down attention and consciousness are distinct phenomena that need not occur together and that can be manipulated using distinct paradigms. Subjects can become conscious of an isolated object or the gist of a scene despite the near absence of top-down attention conversely, subjects can attend to perceptually invisible objects. Furthermore, top-down attention and consciousness can have opposing effects. Such dissociations are easier to understand when the different functions of these two processes are considered. Untangling their tight relationship is necessary for the scientific elucidation of consciousness and its material substrate.
Measuring Integrated Information from the Decoding Perspective
Publisher: Public Library of Science (PLoS)
Date: 21-01-2016
Continuous flash suppression reduces negative afterimages
Publisher: Springer Science and Business Media LLC
Date: 03-07-2005
DOI: 10.1038/NN1500
Abstract: Illusions that produce perceptual suppression despite constant retinal input are used to manipulate visual consciousness. Here we report on a powerful variant of existing techniques, continuous flash suppression. Distinct images flashed successively at approximately 10 Hz into one eye reliably suppress an image presented to the other eye. The duration of perceptual suppression is at least ten times greater than that produced by binocular rivalry. Using this tool we show that the strength of the negative afterimage of an adaptor was reduced by half when it was perceptually suppressed by input from the other eye. The more completely the adaptor was suppressed, the more strongly the afterimage intensity was reduced. Paradoxically, trial-to-trial visibility of the adaptor did not correlate with the degree of reduction. Our results imply that formation of afterimages involves neuronal structures that access input from both eyes but that do not correspond directly to the neuronal correlates of perceptual awareness.
A reply to “the unfolding argument”: Beyond functionalism/behaviorism and towards a science of causal structure theories of consciousness
Publisher: Elsevier BV
Date: 03-2020
Evidence accumulation clustering using combinations of features
Publisher: Center for Open Science
Date: 30-05-2019
Abstract: Evidence accumulation clustering (EAC) is an ensemble clustering algorithm that can cluster data for arbitrary shapes and numbers of clusters. Here, we present a variant of EAC in which we aimed to better cluster data with a large number of features, many of which may be uninformative. Our new method builds on the existing EAC algorithm by populating the clustering ensemble with clusterings based on combinations of fewer features than the original dataset at a time. Our method also calls for prewhitening the recombined data and weighting the influence of each in idual clustering by an estimate of its informativeness. We provide code of an ex le implementation of the algorithm in Matlab and demonstrate its effectiveness compared to ordinary evidence accumulation clustering with synthetic data.
Feedforward connectivity patterns from visual areas to the front of the brain contain information about sensory stimuli regardless of awareness or report
Publisher: Center for Open Science
Date: 02-06-2023
Abstract: Current theories of consciousness can be categorized to some extent by their predictions about the role of the prefrontal cortex (PFC) in conscious perception. One family of theories propose that the PFC is necessary for conscious perception. The other family postulates that the PFC is not necessary and that other areas (e.g., posterior cortical areas) are more important for conscious perception. No-report paradigms could potentially arbitrate the debate as they have been proposed to distinguish the role of the PFC in task reporting from conscious perception. While previous no-report paradigms tend to point to a reduction of PFC activity, they have not examined the critical role of the PFC in “monitoring” the patterns of activity in the sensory cortex to generate conscious perception. To address this, we reanalysed EEG data from a no-report inattentional blindness paradigm (Shafto & Pitts, 2015) to examine the role of feedforward input patterns to the PFC from sensory cortices using nonparametric spectral Granger causality and quantified the amount of information that reflects the contents of consciousness using multivariate classifiers. Strikingly, we found that information relating to the current sensory stimulus was present in the pattern of inputs from sensory to PFC locations regardless of whether the stimulus was consciously seen or not. Such results were unexpected, in that we observed partial support for both posterior and prefrontal theories of consciousness. With respect to the prefrontal theories, our results are inconsistent with their predictions that connectivity between sensory and prefrontal cortices should be modulated by awareness. With respect to the posterior theories, our results are not compatible with their interpretation that prefrontal activation is only associated with the act of report. In further exploratory analyses in the time-domain, we could classify the contents of consciousness at sensory locations, consistent with the posterior theories’ predictions. In light of these findings, we suggest a revised model, such that the contents of consciousness are decodable from the activity within posterior sensory regions, however, the prefrontal cortex is involved in representing the current sensory stimulus regardless of awareness (or report). Our study highlights the need for the theories of consciousness to utilise different types of multi-analysis features and collaborations on a large scale to shed further light on the true NCC and the role of the prefrontal cortex in conscious awareness.
Contrast thresholds for component motion with full and poor attention
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 12-02-2007
DOI: 10.1167/7.3.1
A general spectral decomposition of causal influences applied to integrated information
Publisher: Cold Spring Harbor Laboratory
Date: 07-05-2019
DOI: 10.1101/629014
Abstract: Quantifying causal influences between elements of a system remains a central topic in many fields of research. In neuroscience, causal influences among neurons, quantified as integrated information, have been suggested to play a critical role in supporting subjective conscious experience. Recent empirical work has shown that the spectral decomposition of causal influences can reveal frequency-specific influences that are not observed in the time-domain. To date however, a spectral decomposition of integrated information has not been put forward. In this paper, we propose a spectral decomposition of integrated information in linear autoregressive processes. Our proposal is based on a general and flexible framework for deriving the spectral decompositions of causal influences in autoregressive processes. We show that the framework can retrieve the spectral decompositions of other well-known measures such as Granger causality. In simulation, we demonstrate a complex interplay between the spectral decomposition of integrated information and other measures that is not observed in the time-domain. We propose that the spectral decomposition of integrated information will be particularly useful when the underlying frequency-specific causal influences are masked in the time-domain. The proposed method opens the door for empirically investigating the relevance of integrated information to subjective conscious experience in a frequency-specific manner. Understanding how different parts of the brain influence each other is fundamental to neuroscience. Integrated information measures overall causal influences in the brain and has been theorized to directly relate to subjective consciousness experience. For ex le, integrated information is predicted to be high during wakefulness and low during sleep or general anesthesia. At the same time, neural activity is characterized by well-known spectral signatures. For ex le, there is a prominent increase in low frequency power of neural activity during sleep and general anesthesia. Taking account of the spectral characteristics of neural activity, it is important to separately quantify integrated information at each frequency. In this paper, we propose a method for decomposing integrated information in the frequency domain. The proposed framework is general and can be used to derive the spectral decomposition of other well-known measures such as Granger causality. The spectral decomposition of integrated information we propose will allow empirically investigating the relationship between neural spectral signatures, integrated information and subjective consciousness experience.
Enriched category as a model of qualia structure based on similarity judgements
Publisher: Center for Open Science
Date: 13-06-2021
Abstract: Qualitative relationships between two instances of conscious experiences can be quantified through the perceived similarity. Previously, we proposed that by defining similarity relationships as arrows and conscious experiences as objects, we can define a category of qualia in the context of category theory. However, the ex le qualia categories we proposed were highly idealized and limited to cases where perceived similarity is binary: either present or absent without any gradation. When similarity is graded, a situation can arise where A0 is similar to A1, A1 is similar to A2, and so on, yet A0 is not similar to An, which is called the Sorites paradox. Here, we introduce enriched category theory to address this situation. Enriched categories generalize the concept of a relation between objects as a directed arrow (or morphism) in ordinary category theory to a more flexible notion, such as a measure of distance. As an alternative relation, here we propose a graded measure of perceived dissimilarity between the two objects. These measures combine in a way that addresses the Sorites paradox even if the dissimilarity between Ai and Ai+1 is small for i = 0 … n, hence perceived as similar, the dissimilarity between A0 and An can be large, hence perceived as different. In this way, we show how dissimilarity-enriched categories of qualia resolve the Sorites paradox. We claim that enriched categories accommodate various types of conscious experiences. An important extension of this claim is the application of the Yoneda lemma in enriched category we can characterize a quale through a collection of relationships between the quale and the other qualia up to an (enriched) isomorphism.
Consciousness in humans and non-human animals: recent advances and future directions
Publisher: Frontiers Media SA
Date: 2013
Manifestation of ocular-muscle EMG contamination in human intracranial recordings
Publisher: Elsevier BV
Date: 2011
Motion-induced blindness as a tool to measure attentional biases and the link to attention-deficit/hyperactivity traits.
Publisher: American Psychological Association (APA)
Date: 09-2020
DOI: 10.1037/XGE0000742
Abstract: Typically, in iduals have an attentional bias toward the left visual field. This is often absent in in iduals with attention-deficit/hyperactivity (ADH) disorder (ADHD). We used a motion-induced blindness task with targets in 4 quadrants to assess left/right as well as upper/lower spatial biases in perceptual disappearances and also measured changes in the disappearances with time-on-task. Fifty-eight university students (41 female) completed the Conners Adult ADHD self-report short-form to assess the number of ADH traits, and 48 trials of a 1-min motion-induced blindness (MIB) task. Through a hybrid hypothesis-driven and data-driven analysis approach, we found that the MIB illusion increased with more ADH traits, decreased with time-on-task, and was stronger for left and lower quadrants. The time-on-task likely contributed to the strength of the illusion through changes in arousal, as pupil size decreased with time-on-trial in a subset of participants (
Introduction to Research Topic – Binocular Rivalry: A Gateway to Studying Consciousness
Publisher: Frontiers Media SA
Date: 2012
Emotion and consciousness
Publisher: Elsevier BV
Date: 04-2007
DOI: 10.1016/J.TICS.2007.01.005
Abstract: Consciousness and emotion feature prominently in our personal lives, yet remain enigmatic. Recent advances prompt further distinctions that should provide more experimental traction: we argue that emotion consists of an emotion state (functional aspects, including emotional response) as well as feelings (the conscious experience of the emotion), and that consciousness consists of level (e.g. coma, vegetative state and wakefulness) and content (what it is we are conscious of). Not only is consciousness important to aspects of emotion but structures that are important for emotion, such as brainstem nuclei and midline cortices, overlap with structures that regulate the level of consciousness. The intersection of consciousness and emotion is ripe for experimental investigation, and we outline possible ex les for future studies.
Spatial attention increases performance but not subjective confidence in a discrimination task
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 19-05-2008
DOI: 10.1167/8.5.7
Integrated information structure collapses with anesthetic loss of conscious arousal in Drosophila melanogaster
Publisher: Public Library of Science (PLoS)
Date: 26-02-2021
DOI: 10.1371/JOURNAL.PCBI.1008722
Abstract: The physical basis of consciousness remains one of the most elusive concepts in current science. One influential conjecture is that consciousness is to do with some form of causality, measurable through information. The integrated information theory of consciousness (IIT) proposes that conscious experience, filled with rich and specific content, corresponds directly to a hierarchically organised, irreducible pattern of causal interactions i.e. an integrated informational structure among elements of a system. Here, we tested this conjecture in a simple biological system (fruit flies), estimating the information structure of the system during wakefulness and general anesthesia. Consistent with this conjecture, we found that integrated interactions among populations of neurons during wakefulness collapsed to isolated clusters of interactions during anesthesia. We used classification analysis to quantify the accuracy of discrimination between wakeful and anesthetised states, and found that informational structures inferred conscious states with greater accuracy than a scalar summary of the structure, a measure which is generally ch ioned as the main measure of IIT. In stark contrast to a view which assumes feedforward architecture for insect brains, especially fly visual systems, we found rich information structures, which cannot arise from purely feedforward systems, occurred across the fly brain. Further, these information structures collapsed uniformly across the brain during anesthesia. Our results speak to the potential utility of the novel concept of an “informational structure” as a measure for level of consciousness, above and beyond simple scalar values.
What does it mean to enrich the definition of consciousness in consciousness research using (enriched) category theory?
Publisher: Center for Open Science
Date: 13-03-2020
Abstract: In our recent essay on Cognitive Science [Naotsugu Tsuchiya & Hayato Saigo (2019) “Understanding Consciousness Through Category Theory” vol 26, pp 462 - 477], we provided a general introduction of category theory to consciousness researchers. Further, we also provided our tentative theoretical sketches on our latest ideas on how to apply tools in category theory into consciousness research. In particular, we discussed how we can propose categories of level of consciousness and categories of contents of consciousness. We also speculated what (if any) these efforts will bring into consciousness research. In this short piece, we will address several comments we received on our essay on the same volume from six experts, providing some clarification on three issues: 1) significance of our proposal of a novel viewpoint to enrich what it means to define consciousness, 2) possibility of category theoretical interpretation of consciousness, and 3) understanding of consciousness through the enriched category theoretical framework.
認知発達研究における構造――圏論からのアプローチ――
Publisher: Center for Open Science
Date: 06-02-2023
Abstract: One important problem in current cognitive development research is the lack of theory. In this article, therefore, we propose a cognitive development theory based on mathematical structures. Specifically, we first focus on the concept of structure, which is the concept Piaget introduced to cognitive developmental research. Piaget's theory was mainly inspired by mathematical group and lattice, but many concepts Piaget himself invented (e.g., grouping) were difficult to deal with in a mathematically rigorous manner. Therefore, here, the authors recapture some of the concepts proposed by Piaget in a mathematically understandable form based on the concept of mathematical category, a generalization of the group. Furthermore, we would like to introduce cognitive developmental research on structural concepts since Piaget and suggest directions for future research.
Team Flow Is a Unique Brain State Associated with Enhanced Information Integration and Interbrain Synchrony
Publisher: Society for Neuroscience
Date: 09-2021
DOI: 10.1523/ENEURO.0133-21.2021
Abstract: Team flow occurs when a group functions in a high task engagement to achieve a goal, commonly seen in performance and sports. Team flow can enable enhanced positive experiences, as compared with in idual flow or regular socializing. However, the neural basis for this enhanced behavioral state remains unclear. Here, we identified neural correlates (NCs) of team flow in human participants using a music rhythm task with electroencephalogram hyperscanning. Experimental manipulations held the motor task constant while disrupting the corresponding hedonic music to interfere with the flow state or occluding the partner’s positive feedback to impede team interaction. We validated these manipulations by using psychometric ratings and an objective measure for the depth of flow experience, which uses the auditory-evoked potential (AEP) of a task-irrelevant stimulus. Spectral power analysis at both the scalp sensors and anatomic source levels revealed higher β-γ power specific to team flow in the left middle temporal cortex (L-MTC). Causal interaction analysis revealed that the L-MTC is downstream in information processing and receives information from areas encoding the flow or social states. The L-MTC significantly contributes to integrating information. Moreover, we found that team flow enhances global interbrain integrated information (II) and neural synchrony. We conclude that the NCs of team flow induce a distinct brain state. Our results suggest a neurocognitive mechanism to create this unique experience.
Enriched category as a model of qualia structure based on similarity judgements
Publisher: Center for Open Science
Date: 29-06-2021
Abstract: Qualitative relationships between two instances of conscious experiences can be quantified through the perceived similarity. Previously, we proposed that by defining similarity relationships as arrows and conscious experiences as objects, we can define a category of qualia in the context of category theory. However, the ex le qualia categories we proposed were highly idealized and limited to cases where perceived similarity is binary: either present or absent without any gradation. Here, we introduce enriched category theory to address the graded levels of similarity that arises in many instances of qualia. Enriched categories generalize the concept of a relation between objects as a directed arrow (or morphism) in ordinary category theory to a more flexible notion, such as a measure of distance. As an alternative relation, here we propose a graded measure of perceived dissimilarity between the two objects. We claim that enriched categories accommodate various types of conscious experiences. An important extension of this claim is the application of the Yoneda lemma in enriched category we can characterize a quale through a collection of relationships between the quale and the other qualia up to an (enriched) isomorphism.
Reasonable criteria for functionalists; scarce criteria from phenomenological perspective
Publisher: Center for Open Science
Date: 14-09-2020
Abstract: In their article (Doerig et al., 2020), Doerig et al suggest a set of criteria for evaluating theories of consciousness. Naturally, their criteria are situated in their own particular perspective on consciousness science (Doerig et al., 2019), which we have critiqued in the past (Tsuchiya et al., 2020). Their first criterion is likely to be the one that is most productive and least contentious: if the field can agree to a family of paradigm cases for consciousness, this would be an important endeavor for the field.
Parkinson's disease alters multisensory perception
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2017.01.031
Abstract: Manipulation of multisensory integration induces illusory perceptions of body ownership. Patients with Parkinson's disease (PD), a neurodegenerative disorder characterised by striatal dopamine deficiency, are prone to illusions and hallucinations and have sensory deficits. Dopaminergic treatment also aggravates hallucinations in PD. Whether multisensory integration in body ownership is altered by PD is unexplored. To study the effect of dopamine neurotransmission on illusory perceptions of body ownership. We studied the Rubber Hand Illusion (RHI) in 21 PD patients (on- and off-medication) and 21 controls. In this experimental paradigm, synchronous stroking of a rubber hand and the subject's hidden real hand results in the illusory experience of 'feeling' the rubber hand, and proprioceptive mislocalisation of the real hand towards the rubber hand ('proprioceptive drift'). Asynchronous stroking typically attenuates the RHI. The effect of PD on illusory experience depended on the stroking condition (b = -2.15, 95% CI [-3.06, -1.25], p < .0001): patients scored questionnaire items eliciting the RHI experience higher than controls in the illusion-attenuating (asynchronous) condition, but not in the illusion-promoting (synchronous) condition. PD, independent of stroking condition, predicted greater proprioceptive drift (b = 15.05, 95% CI [6.05, 24.05], p = .0022) the longer the disease duration, the greater the proprioceptive drift. However, the RHI did not affect subsequent reaching actions. On-medication patients scored both illusion (critical) and mock (control) questionnaire items higher than when off-medication, an effect that increased with disease severity (log (OR) =.014, 95% CI [.01, .02], p < .0001). PD affects illusory perceptions of body ownership in situations that do not typically induce them, implicating dopamine deficit and consequent alterations in cortico-basal ganglia-thalamic circuitry in multisensory integration. Dopaminergic treatment appears to increase suggestibility generally rather than having a specific effect on own-body illusions, a novel finding with clinical and research implications.
“What is it like to be a bat?”—a pathway to the answer from the integrated information theory
Publisher: Wiley
Date: 03-2017
DOI: 10.1111/PHC3.12407
Top-down attention and consciousness: comment on Cohen et al.
Publisher: Elsevier BV
Date: 11-2012
Simulated forward and backward self motion, based on realistic parameters, causes motion induced blindness
Publisher: Springer Science and Business Media LLC
Date: 29-08-2017
DOI: 10.1038/S41598-017-09424-6
Abstract: Motion Induced Blindness (MIB) is a well-established visual phenomenon whereby highly salient targets disappear when viewed against a moving background mask. No research has yet explored whether contracting and expanding optic flow can also trigger target disappearance. We explored MIB using mask speeds corresponding to driving at 35, 50, 65 and 80 km/h in simulated forward (expansion) and backward (contraction) motion as well as 2-D radial movement, random, and static mask motion types. Participants (n = 18) viewed MIB targets against masks with different movement types, speed, and target locations. To understand the relationship between saccades, pupil response and perceptual disappearance, we ran two additional eye-tracking experiments (n = 19). Target disappearance increased significantly with faster mask speeds and upper visual field target presentation. Simulated optic flow and 2-D radial movement caused comparable disappearance, and all moving masks caused significantly more disappearance than a static mask. Saccades could not entirely account for differences between conditions, suggesting that self-motion optic flow does cause MIB in an artificial setting. Pupil analyses implied that MIB disappearance induced by optic flow is not subjectively salient, potentially explaining why MIB is not noticed during driving. Potential implications of MIB for driving safety and Head-Up-Display (HUD) technologies are discussed.
Neural markers of predictive coding under perceptual uncertainty revealed with Hierarchical Frequency Tagging
Publisher: eLife Sciences Publications, Ltd
Date: 28-02-2017
DOI: 10.7554/ELIFE.22749
Abstract: There is a growing understanding that both top-down and bottom-up signals underlie perception. But it is not known how these signals integrate with each other and how this depends on the perceived stimuli’s predictability. ‘Predictive coding’ theories describe this integration in terms of how well top-down predictions fit with bottom-up sensory input. Identifying neural markers for such signal integration is therefore essential for the study of perception and predictive coding theories. To achieve this, we combined EEG methods that preferentially tag different levels in the visual hierarchy. Importantly, we examined intermodulation components as a measure of integration between these signals. Our results link the different signals to core aspects of predictive coding, and suggest that top-down predictions indeed integrate with bottom-up signals in a manner that is modulated by the predictability of the sensory input, providing evidence for predictive coding and opening new avenues to studying such interactions in perception.
Spatial Attention Is Attracted in a Sustained Fashion toward Singular Points in the Optic Flow
Publisher: Public Library of Science (PLoS)
Date: 08-08-2012
Hierarchical Frequency Tagging reveals neural markers of predictive coding under varying uncertainty
Publisher: Cold Spring Harbor Laboratory
Date: 17-10-2016
DOI: 10.1101/081349
Abstract: Understanding the integration of top-down and bottom-up signals is essential for the study of perception. Current accounts of predictive coding describe this in terms of interactions between state units encoding expectations or predictions, and error units encoding prediction error. However, direct neural evidence for such interactions has not been well established. To achieve this, we combined EEG methods that preferentially tag different levels in the visual hierarchy: Steady State Visual Evoked Potential (SSVEP at 10Hz, tracking bottom-up signals) and Semantic Wavelet-Induced Frequency Tagging (SWIFT at 1.3Hz tracking top-down signals). Importantly, we examined intermodulation components (IM, e.g., 11.3Hz) as a measure of integration between these signals. To examine the influence of expectation and predictions on the nature of such integration, we constructed 50-second movie streams and modulated expectation levels for upcoming stimuli by varying the proportion of images presented across trials. We found SWIFT, SSVEP and IM signals to differ in important ways. SSVEP was strongest over occipital electrodes and was not modified by certainty. Conversely, SWIFT signals were evident over temporo- and parieto-occipital areas and decreased as a function of increasing certainty levels. Finally, IMs were evident over occipital electrodes and increased as a function of certainty. These results link SSVEP, SWIFT and IM signals to sensory evidence, predictions, prediction errors and hypothesis-testing - the core elements of predictive coding. These findings provide neural evidence for the integration of top-down and bottom-up information in perception, opening new avenues to studying such interactions in perception while constraining neuronal models of predictive coding. There is a growing understanding that both top-down and bottom-up signals underlie perception. But how do these signals interact? And how does this process depend on the signals’ probabilistic properties? ‘Predictive coding’ theories of perception describe this in terms how well top-down predictions fit with bottom-up sensory input. Identifying neural markers for such signal integration is therefore essential for the study of perception and predictive coding theories in particular. The novel Hierarchical Frequency Tagging method simultaneously tags top-down and bottom-up signals in EEG recordings, while obtaining a measure for the level of integration between these signals. Our results suggest that top-down predictions indeed integrate with bottom-up signals in a manner that is modulated by the predictability of the sensory input.
Decoding Face Information in Time, Frequency and Space from Direct Intracranial Recordings of the Human Brain
Publisher: Public Library of Science (PLoS)
Date: 09-12-2008
Enriched category as a model of qualia structure based on similarity judgements
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.CONCOG.2022.103319
Abstract: Qualitative relationships between two instances of conscious experiences can be quantified through the perceived similarity. Previously, we proposed that by defining similarity relationships as arrows and conscious experiences as objects, we can define a category of qualia in the context of category theory. However, the ex le qualia categories we proposed were highly idealized and limited to cases where perceived similarity is binary: either present or absent without any gradation. Here, we introduce enriched category theory to address the graded levels of similarity that arises in many instances of qualia. Enriched categories generalize the concept of a relation between objects as a directed arrow (or morphism) in ordinary category theory to a more flexible notion, such as a measure of distance. As an alternative relation, here we propose a graded measure of perceived dissimilarity between the two objects. We claim that enriched categories accommodate various types of conscious experiences. An important consequence of this claim is the application of the Yoneda lemma in enriched category we can characterize a quale through a collection of relationships between the quale and the other qualia up to an (enriched) isomorphism.
A unified framework for dissecting the effects of common signals on functional and effective connectivity analyses: power, coherence, and Granger causality
Publisher: Cold Spring Harbor Laboratory
Date: 08-09-2017
DOI: 10.1101/186122
Abstract: When analyzing neural data it is important to consider the limitations of the particular experimental setup. An enduring issue in the context of electrophysiology is the presence of common signals. For ex le a non-silent reference electrode adds a common signal across all recorded data and this adversely affects functional and effective connectivity analysis. To address the common signals problem, a number of methods have been proposed, but relatively few detailed investigations have been carried out. We address this gap by analyzing local field potentials recorded from the small brains of fruit flies. We conduct our analysis following a solid mathematical framework that allows us to make precise predictions regarding the nature of the common signals. We demonstrate how a framework that jointly analyzes power, coherence and quantities from the Granger causality framework allows us to detect and assess the nature of the common signals. Our analysis revealed substantial common signals in our data, in part due to a non-silent reference electrode. We further show that subtracting spatially adjacent signals (bipolar rereferencing) largely removes the effects of the common signals. However, in some special cases this operation itself introduces a common signal. The mathematical framework and analysis pipeline we present can readily be used by others to detect and assess the nature of the common signals in their data, thereby reducing the chance of misinterpreting the results of functional and effective connectivity analysis.
Stage 1 Registered Report: Do psychological diversities contribute to preventing the coronavirus spread? Testing a neurodiversity hypothesis amidst the COVID-19 pandemic
Publisher: F1000 Research Ltd
Date: 19-04-2022
DOI: 10.12688/F1000RESEARCH.111280.1
Abstract: Background: Contemporary societies lack direct evidence that ersity of neuro-origin psychological traits – neuro ersity – benefits the human species. Psychological ersities including those with heightened traits of obsessive-compulsiveness (OC) may play a critical preventative role amidst a pandemic because of their natural dispositions for immunizing cognitions and behaviors based on obsessive pathogen concerns. We aim to test this notion in the context of the coronavirus disease 2019 (COVID-19) pandemic. Methods: We will conduct an online survey examining the hypotheses that in iduals with higher psychological traits of OC are less likely to get infected while they show enhanced self-diagnosis of infection. Conclusions: Such results would suggest that those generally perceived as “psychological minorities” due to increased pathogen concerns may serve preventive roles against pandemics at both in idual and collective levels.
Response to Mole: Subjects can attend to completely invisible objects
Publisher: Elsevier BV
Date: 02-2008
Separating weak integrated information theory into inspired and aspirational approaches
Publisher: Oxford University Press (OUP)
Date: 2023
DOI: 10.1093/NC/NIAD012
Abstract: Mediano et al. (The strength of weak integrated information theory. Trends Cogn Sci 2022 : 646–55.) separate out strong and weak flavours of the integrated information theory (IIT) of consciousness. They describe ‘strong IIT’ as attempting to derive a universal formula for consciousness and ‘weak IIT’ as searching for empirically measurable correlates of aspects of consciousness. We put forward that their overall notion of ‘weak IIT’ may be too weak. Rather, it should be separated out to distinguish ‘aspirational-IIT’, which aims to empirically test IIT by making trade-offs to its proposed measures, and ‘IIT-inspired’ approaches, which adopt high-level ideas of IIT while dropping the mathematical framework it reaches through its introspective, first-principles approach to consciousness.
Phenomenology without conscious access is a form of consciousness without top-down attention
Publisher: Cambridge University Press (CUP)
Date: 12-2007
DOI: 10.1017/S0140525X07002907
Abstract: We agree with Block's basic hypothesis postulating the existence of phenomenal consciousness without cognitive access. We explain such states in terms of consciousness without top-down, endogenous attention and speculate that their correlates may be a coalition of neurons that are consigned to the back of cortex, without access to working memory and planning in frontal cortex.
Author response: Neural markers of predictive coding under perceptual uncertainty revealed with Hierarchical Frequency Tagging
Publisher: eLife Sciences Publications, Ltd
Date: 17-02-2017
The SSVEP tracks attention, not consciousness, during perceptual filling-in
Publisher: eLife Sciences Publications, Ltd
Date: 10-11-2020
DOI: 10.7554/ELIFE.60031
Abstract: Research on the neural basis of conscious perception has almost exclusively shown that becoming aware of a stimulus leads to increased neural responses. By designing a novel form of perceptual filling-in (PFI) overlaid with a dynamic texture display, we frequency-tagged multiple disappearing targets as well as their surroundings. We show that in a PFI paradigm, the disappearance of a stimulus and subjective invisibility is associated with increases in neural activity, as measured with steady-state visually evoked potentials (SSVEPs), in electroencephalography (EEG). We also find that this increase correlates with alpha-band activity, a well-established neural measure of attention. These findings cast doubt on the direct relationship previously reported between the strength of neural activity and conscious perception, at least when measured with current tools, such as the SSVEP. Instead, we conclude that SSVEP strength more closely measures changes in attention.
Qualia Structure Proposal (English version)
Publisher: Center for Open Science
Date: 15-07-2023
Abstract: Summary: Establishing Qualia Structure Paradigm.?Do subjective conscious experience and objective brain matters belong to completely different worlds? How are qualia, the contents of consciousness, related to the brain? The question of consciousness and the brain is not only of scientific interest, but it is also directly related to the problems associated with difficulties in understanding human feelings in the real world. Because qualia are difficult to even define in objective terms, conventional studies of consciousness have attempted to explore their neural correlates by fixing perceptual stimuli and reducing experience to binary judgments, such as seen vs. not seen. Recently, we have established a new paradigm to characterize the structure of qualia by measuring the similarity between visual qualia on a large scale, and to reveal their neural correlates and their information structure. The Qualia Structure project will further employ various research methods, including phenomenology, development, and constructivism, in order to estimate structures of qualia from perceptual to emotional domains. The outcome of this field is the creation of a new interdisciplinary research program that will have impacts to the general society, such as understanding the consciousness of others and the consciousness of animals and artificial intelligence.
Unified framework for information integration based on information geometry
Publisher: Proceedings of the National Academy of Sciences
Date: 06-12-2016
Abstract: Measuring the degree of causal influences among multiple elements of a system is a fundamental problem in physics and biology. We propose a unified framework for quantifying any combination of causal relationships between elements in a hierarchical manner based on information geometry. Our measure of integration, called geometrical integrated information, quantifies the strength of multiple causal influences among elements by projecting the probability distribution of a system onto a constrained manifold. This measure overcomes mathematical problems of existing measures and enables an intuitive understanding of the relationships between integrated information and other measures of causal influence such as transfer entropy. Inspired by the integration of neural activity in consciousness studies, our measure should have general utility in analyzing complex systems.
Is recurrent processing necessary and/or sufficient for consciousness?
Publisher: Informa UK Limited
Date: 18-08-2010
DOI: 10.1080/17588928.2010.497582
Abstract: Abstract Abstract While we agree with Lamme's general framework, we are not so convinced by his mapping between psychological concepts with their underlying neuronal mechanisms. Specifically, we doubt if recurrent processing is either necessary or sufficient for consciousness. A gist of a scene may be consciously perceived by purely feedforward, without recurrent, processing. Neurophysiological studies of perceptual suppression show recurrent processing in visual cortex for consciously invisible objects. While the neuronal correlates of attention and consciousness remain to be clarified, we agree with Lamme that these two processes are independent, evinced by our recent demonstration of opposing effects of attention and consciousness.
Using category theory to assess the relationship between consciousness and integrated information theory
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.NEURES.2015.12.007
Abstract: One of the most mysterious phenomena in science is the nature of conscious experience. Due to its subjective nature, a reductionist approach is having a hard time in addressing some fundamental questions about consciousness. These questions are squarely and quantitatively tackled by a recently developed theoretical framework, called integrated information theory (IIT) of consciousness. In particular, IIT proposes that a maximally irreducible conceptual structure (MICS) is identical to conscious experience. However, there has been no principled way to assess the claimed identity. Here, we propose to apply a mathematical formalism, category theory, to assess the proposed identity and suggest that it is important to consider if there exists a proper translation between the domain of conscious experience and that of the MICS. If such translation exists, we postulate that questions in one domain can be answered in the other domain very difficult questions in the domain of consciousness can be resolved in the domain of mathematics. We claim that it is possible to empirically test if such a functor exists, by using a combination of neuroscientific and computational approaches. Our general, principled and empirical framework allows us to assess the relationship between the domain of consciousness and the domain of mathematical structures, including those suggested by IIT.
What can we experience and report on a rapidly presented image? Intersubjective measures of specificity of freely reported contents of consciousness
Publisher: F1000 Research Ltd
Date: 24-08-2022
DOI: 10.12688/F1000RESEARCH.75364.2
Abstract: Background: A majority of previous studies appear to support a view that human observers can only perceive coarse information from a natural scene image when it is presented rapidly ( ms, masked). In these studies, participants were often forced to choose an answer from options that experimenters preselected. These options can underestimate what participants experience and can report on it. The current study aims to introduce a novel methodology to investigate how detailed information participants can report after briefly seeing a natural scene image. Methods: We used a novel free-report paradigm to examine what people can freely report following a rapidly presented natural scene image (67/133/267ms, masked). N = 600 online participants typed up to five words to report what they saw in the image together with confidence of the respective responses. We developed a novel index, Intersubjective Agreement (IA). IA quantifies how specifically the response words were used to describe the target image, with a high value meaning the word is not often reported for other images. Importantly, IA eliminates the need for experimenters to preselect response options. Results: The words with high IA values are often something detailed (e.g., a small object) in a particular image. With IA, unlike commonly believed, we demonstrated that participants reported highly specific and detailed aspects of the briefly (even at 67ms, masked) shown image. Further, IA is positively correlated with confidence, indicating metacognitive conscious access to the reported aspects of the image. Conclusion: These new findings challenge the dominant view that the content of rapid scene experience is limited to global and coarse gist. Our novel paradigm opens a door to investigate various contents of consciousness with a free-report paradigm.
Qualia Structure Proposal (Japanese version)
Publisher: Center for Open Science
Date: 15-07-2023
Abstract: 主観意識と客観的な物質としての脳は、全く異なる世界に属すのだろうか? 意識の中身であるクオリアと脳はいかに関係しているのか? 意識と脳の問題は、科学的な興味に留まらず、現実社会における人の気持ちの理解の困難に伴う問題にも直接関わる。意識のクオリアは、客観的な言語で定義することすら難しいため、従来の意識研究では、知覚刺激を固定し、経験を「見えた・見えない」という二値的な判断に還元し、その神経相関の探求を試みた。近年、我々は視覚クオリア間の類似度を大規模に計測することでクオリアの構造を特徴づけ、その神経相関とその情報構造を明らかにする新パラダイムを確立した。本領域は、現象学・発達・構成論を加え、知覚と感情クオリアに集中することで、クオリア構造学を創成する。本領域の成果は、他者意識の理解や、動物や人工物の意識理解など、一般社会へも広く還元されうる答えを生み出す新融合領域の創成である。
Visual awareness of others’ facial expressions during binocular rivalry under tactile stimulation on the viewer’s face
Publisher: Center for Open Science
Date: 26-01-2023
Abstract: Sensorimotor simulation theory offers potential to explain the mechanisms that underpin the ability to recognize others’ emotions. In this vein, recent models propose a key role for the somatosensory cortex (SC) in emotion recognition. In addition, recent evidence suggests that the subjective experience from the perception of a facial expression is linked with responses in the SC but not with responses in the motor cortex. Furthermore, models of sensorimotor simulation converge on the idea that somatosensory representations and visual representations are integrated. Here, we want to test whether somatosensory activity during the perception of facial expressions has a role in conscious processing of such expressions, an issue that has been ignored by previous research. To this aim we will present facial expressions in binocular rivalry, a well-suited paradigm employed in behavioral and neuroimaging studies of conscious visual perception. We expect that congruent tactile facial stimulation with the somatosensory representations of happy expressions will favor the conscious content of happy facial expressions and interfere with conscious processing of neutral expressions compared to the absence of tactile stimulation.
Predicting lapses of attention with sleep-like slow waves
Publisher: Springer Science and Business Media LLC
Date: 29-06-2021
DOI: 10.1038/S41467-021-23890-7
Abstract: Attentional lapses occur commonly and are associated with mind wandering, where focus is turned to thoughts unrelated to ongoing tasks and environmental demands, or mind blanking, where the stream of consciousness itself comes to a halt. To understand the neural mechanisms underlying attentional lapses, we studied the behaviour, subjective experience and neural activity of healthy participants performing a task. Random interruptions prompted participants to indicate their mental states as task-focused, mind-wandering or mind-blanking. Using high-density electroencephalography, we report here that spatially and temporally localized slow waves, a pattern of neural activity characteristic of the transition toward sleep, accompany behavioural markers of lapses and preceded reports of mind wandering and mind blanking. The location of slow waves could distinguish between sluggish and impulsive behaviours, and between mind wandering and mind blanking. Our results suggest attentional lapses share a common physiological origin: the emergence of local sleep-like activity within the awake brain.
Attention and consciousness: related yet different
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.TICS.2011.11.012
Abstract: A recent perceptual imaging experiment uses a rare 2×2 design to dissociate selective visual attention from visual consciousness. Its conclusions support the hypothesis that visual consciousness does not arise from neurons in primary visual cortex and forces a reinterpretation of numerous prior studies.
Unifying pairwise interactions in complex dynamics
Publisher: Springer Science and Business Media LLC
Date: 25-09-2023
Consciousness and Attention: On Sufficiency and Necessity
Publisher: Frontiers Media SA
Date: 2010
Frequency-dependent spatiotemporal profiles of visual responses recorded with subdural ECoG electrodes in awake monkeys: Differences between high- and low-frequency activity
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.NEUROIMAGE.2015.09.007
Abstract: Electrocorticography (ECoG) constitutes a powerful and promising neural recording modality in humans and animals. ECoG signals are often decomposed into several frequency bands, among which the so-called high-gamma band (80-250Hz) has been proposed to reflect local cortical functions near the cortical surface below the ECoG electrodes. It is typically assumed that the lower the frequency bands, the lower the spatial resolution of the signals thus, there is not much to gain by analyzing the event-related changes of the ECoG signals in the lower-frequency bands. However, differences across frequency bands have not been systematically investigated. To address this issue, we recorded ECoG activity from two awake monkeys performing a retinotopic mapping task. We characterized the spatiotemporal profiles of the visual responses in the time-frequency domain. We defined the preferred spatial position, receptive field (RF), and response latencies of band-limited power (BLP) (i.e., alpha [3.9-11.7Hz], beta [15.6-23.4Hz], low [30-80Hz] and high [80-250Hz] gamma) for each electrode and compared them across bands and time-domain visual evoked potentials (VEPs). At the population level, we found that the spatial preferences were comparable across bands and VEPs. The high-gamma power showed a smaller RF than the other bands and VEPs. The response latencies for the alpha band were always longer than the latencies for the other bands and fastest in VEPs. Comparing the response profiles in both space and time for each cortical region (V1, V4+, and TEO/TE) revealed regional idiosyncrasies. Although the latencies of visual responses in the beta, low-, and high-gamma bands were almost identical in V1 and V4+, beta and low-gamma BLP occurred about 17ms earlier than high-gamma power in TEO/TE. Furthermore, TEO/TE exhibited a unique pattern in the spatial response profile: the alpha and high-gamma responses tended to prefer the foveal regions, whereas the beta and low-gamma responses preferred the peripheral visual fields with larger RFs. This suggests that neurons in TEO/TE first receive less selective spatial information via beta and low-gamma BLP but later receive more fine-tuned spatial foveal information via high-gamma power. This result is consistent with a hypothesis previously proposed by Nakamura et al. (1993) that states that visual processing in TEO/TE starts with coarse-grained information, which primes subsequent fine-grained information. Collectively, our results demonstrate that ECoG can be a potent tool for investigating the nature of the neural computations in each cortical region that cannot be fully understood by measuring only the spiking activity, through the incorporation of the knowledge of the spatiotemporal characteristics across all frequency bands.
A neural representation of invisibility: when stimulus-specific neural activity negatively correlates with conscious experience
Publisher: Cold Spring Harbor Laboratory
Date: 21-04-2020
DOI: 10.1101/2020.04.20.051334
Abstract: Although visual awareness of an object typically increases neural responses, we identify a neural response that increases prior to perceptual disappearances , and that scales with the amount of invisibility reported during perceptual filling-in. These findings challenge long-held assumptions regarding the neural correlates of consciousness and entrained visually evoked potentials, by showing that the strength of stimulus-specific neural activity can encode the conscious absence of a stimulus. The focus of attention and the contents of consciousness frequently overlap. Yet what happens if this common correlation is broken? To test this, we asked human participants to attend and report on the invisibility of four visual objects which seemed to disappear, yet actually remained on screen. We found that neural activity increased, rather than decreased, when targets became invisible. This coincided with measures of attention that also increased when stimuli disappeared. Together, our data support recent suggestions that attention and conscious perception are distinct and separable. In our experiment, neural measures more strongly follow attention.
Working memory and fear conditioning
Publisher: Proceedings of the National Academy of Sciences
Date: 27-01-2003
Abstract: Previous studies of associative learning implicate higher-level cognitive processes in some forms of classical conditioning. An ongoing debate is concerned with the extent to which attention and awareness are necessary for trace but not delay eye-blink conditioning [Clark, R. E. & Squire, L. R. (1998) Science 280, 77–81 Lovibond, P. F. & Shanks, D. (2002) J. Exp. Psychol. Anim. Behav. Processes 28, 38–42]. In trace conditioning, a short interval is interposed between the termination of the conditioned stimulus (CS) and the onset of the unconditioned stimulus (US). In delay conditioning, the CS and US overlap. We here investigate the extent to which human classical fear conditioning depends on working memory. Subjects had to carry out an n -back task, requiring tracking an item 1 or 2 back in a sequentially presented list of numbers, while simultaneously being tested for their ability to associate auditory cues with shocks under a variety of conditions (single-cue versus differential delay versus trace no task versus 0-, 1-, and 2-back). Differential delay conditioning proved to be more resilient than differential trace conditioning but does show a reduction due to task interference similar in slope to that found in trace conditioning. Explicit knowledge of the stimulus contingency facilitates but does not guarantee trace conditioning. Only the single-cue delay protocol shows conditioning during the more difficult working memory task. Our findings suggest that the larger the cognitive demands on the system, the less likely conditioning occurs. A postexperimental questionnaire showed a positive correlation between conditioning and awareness for differential trace conditioning extinction.
A category-specific response to animals in the right human amygdala
Publisher: Springer Science and Business Media LLC
Date: 28-08-2011
DOI: 10.1038/NN.2899
Isoflurane reduces feedback in the fruit fly brain
Publisher: Cold Spring Harbor Laboratory
Date: 12-07-2017
DOI: 10.1101/161976
Abstract: Hierarchically organized brains communicate through feedforward and feedback pathways. In mammals, feedforward and feedback are mediated by higher and lower frequencies during wakefulness. Feedback is preferentially impaired by general anesthetics. This suggests feedback serves critical functions in waking brains. The brain of Drosophila melanogaster (fruit fly) is also hierarchically organized, but the presence of feedback in these brains is not established. Here we studied feedback in the fruit fly brain, by simultaneously recording local field potentials (LFPs) from low-order peripheral structures and higher-order central structures. Directed connectivity analysis revealed that low frequencies (0.1-5Hz) mediated feedback from the center to the periphery, while higher frequencies (10-45Hz) mediated feedforward in the opposite direction. Further, isoflurane anesthesia preferentially reduced feedback. Our results imply that similar spectral characteristics of feedforward and feedback may be a signature of hierarchically organized brains and that general anesthetics may induce unresponsiveness by targeting the mechanisms that support feedback.
Conscious machines: Defining questions.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-01-2018
Sustained conscious access to incidental memories in RSVP.
Publisher: Springer Science and Business Media LLC
Date: 05-10-2019
DOI: 10.3758/S13414-018-1600-1
Abstract: In visual search of natural scenes, differentiation of briefly fixated but task-irrelevant distractor items from incidental memory is often comparable to explicit memorization. However, many characteristics of incidental memory remain unclear, including the capacity for its conscious retrieval. Here, we examined incidental memory for faces in either upright or inverted orientation using Rapid Serial Visual Presentation (RSVP). Subjects were instructed to detect a target face in a sequence of 8-15 faces cropped from natural scene photographs (Experiment 1). If the target face was identified within a brief time window, the subject proceeded to an incidental memory task. Here, subjects used incidental memory to discriminate between a probe face (a distractor in the RSVP stream) and a novel, foil face. In Experiment 2 we reduced scene-related semantic coherency by intermixing faces from multiple scenes and contrasted incidental memory with explicit memory, a condition where subjects actively memorized each face from the sequence without searching for a target. In both experiments, we measured objective performance (Type 1 AUC) and metacognitive accuracy (Type 2 AUC), revealing sustained and consciously accessible incidental memory for upright and inverted faces. In novel analyses of face categories, we examined whether accuracy or metacognitive judgments are affected by shared semantic features (i.e., similarity in gender, race, age). Similarity enhanced the accuracy of incidental memory discriminations but did not influence metacognition. We conclude that incidental memory is sustained and consciously accessible, is not reliant on scene contexts, and is not enhanced by explicit memorization.
Isoflurane Impairs Low-Frequency Feedback but Leaves High-Frequency Feedforward Connectivity Intact in the Fly Brain
Publisher: Society for Neuroscience
Date: 2018
DOI: 10.1523/ENEURO.0329-17.2018
Abstract: Hierarchically organized brains communicate through feedforward (FF) and feedback (FB) pathways. In mammals, FF and FB are mediated by higher and lower frequencies during wakefulness. FB is preferentially impaired by general anesthetics in multiple mammalian species. This suggests FB serves critical functions in waking brains. The brain of Drosophila melanogaster (fruit fly) is also hierarchically organized, but the presence of FB in these brains is not established. Here, we studied FB in the fly brain, by simultaneously recording local field potentials (LFPs) from low-order peripheral structures and higher-order central structures. We analyzed the data using Granger causality (GC), the first application of this analysis technique to recordings from the insect brain. Our analysis revealed that low frequencies (0.1–5 Hz) mediated FB from the center to the periphery, while higher frequencies (10–45 Hz) mediated FF in the opposite direction. Further, isoflurane anesthesia preferentially reduced FB. Our results imply that the spectral characteristics of FF and FB may be a signature of hierarchically organized brains that is conserved from insects to mammals. We speculate that general anesthetics may induce unresponsiveness across species by targeting the mechanisms that support FB.
Team flow is a unique brain state associated with enhanced information integration and neural synchrony
Publisher: Cold Spring Harbor Laboratory
Date: 19-06-2020
DOI: 10.1101/2020.06.17.157990
Abstract: Team flow occurs when a group of people reaches high task engagement while sharing a common goal as in sports teams and music bands. While team flow is a superior enjoyable experience to in iduals experiencing flow or regular socialization, the neural basis for such superiority is still unclear. Here, we addressed this question utilizing a music rhythm task and electroencephalogram hyper-scanning. Experimental manipulations held the motor task constant while disrupted the hedonic musical correspondence to blocking flow or occluded the partner’s body and task feedback to block social interaction. The manipulations’ effectiveness was confirmed using psychometric ratings and an objective measure for the depth of flow experience through the inhibition of the auditory-evoked potential to a task-irrelevant stimulus. Spectral power analysis revealed higher beta/gamma power specific to team flow at the left temporal cortex. Causal interaction analysis revealed that the left temporal cortex receives information from areas encoding in idual flow or socialization. The left temporal cortex was also significantly involved in integrated information at both the intra- and inter-brains levels. Moreover, team flow resulted in enhanced global inter-brain integrated information and neural synchrony. Thus, our report presents neural evidence that team flow results in a distinct brain state and suggests a neurocognitive mechanism by which the brain creates this unique experience. All data and analysis codes used in the preparation of this article are available at osf.io/3b4hp .
A Quantum Geometric Framework for Modeling Color Similarity Judgments
Publisher: Wiley
Date: 2023
DOI: 10.1111/COGS.13231
Abstract: Since Tversky argued that similarity judgments violate the three metric axioms, asymmetrical similarity judgments have been particularly challenging for standard, geometric models of similarity, such as multidimensional scaling. According to Tversky, asymmetrical similarity judgments are driven by differences in salience or extent of knowledge. However, the notion of salience has been difficult to operationalize, especially for perceptual stimuli for which there are no apparent differences in extent of knowledge. To investigate similarity judgments between perceptual stimuli, across three experiments, we collected data where in iduals would rate the similarity of a pair of temporally separated color patches. We identified several violations of symmetry in the empirical results, which the conventional multidimensional scaling model cannot readily capture. Pothos et al. proposed a quantum geometric model of similarity to account for Tversky's findings. In the present work, we extended this model to a more general framework that can be fit to similarity judgments. We fitted several variants of quantum and multidimensional scaling models to the behavioral data and concluded in favor of the quantum approach. Without further modifications of the model, the best‐fit quantum model additionally predicted violations of the triangle inequality that we observed in the same data. Overall, by offering a different form of geometric representation, the quantum geometric framework of similarity provides a viable alternative to multidimensional scaling for modeling similarity judgments, while still allowing a convenient, spatial illustration of similarity.
Conscious Perception as Integrated Information Patterns in Human Electrocorticography
Publisher: Society for Neuroscience
Date: 09-2017
DOI: 10.1523/ENEURO.0085-17.2017
Abstract: A significant problem in neuroscience concerns the distinction between neural processing that is correlated with conscious percepts from processing that is not. Here, we tested if a hierarchical structure of causal interactions between neuronal populations correlates with conscious perception. We derived the hierarchical causal structure as a pattern of integrated information, inspired by the integrated information theory (IIT) of consciousness. We computed integrated information patterns from intracranial electrocorticography (ECoG) from six human neurosurgical patients with electrodes implanted over lateral and ventral cortices. During recording, subjects viewed continuous flash suppression (CFS) and backward masking (BM) stimuli intended to dissociate conscious percept from stimulus, and unmasked suprathreshold stimuli. Object-sensitive areas revealed correspondence between conscious percepts and integrated information patterns. We quantified this correspondence using unsupervised classification methods that revealed clustering of visual experiences with integrated information, but not with broader information measures including mutual information and entropy. Our findings point to a significant role of locally integrated information for understanding the neural substrate of conscious object perception.
Qualia Structure B Grant Proposal S75 76 77
Publisher: Center for Open Science
Date: 15-05-2023
Abstract: This is a grant proposal for Qualia Structure B (2020-2023).
No-Report Paradigms: Extracting the True Neural Correlates of Consciousness
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.TICS.2015.10.002
Abstract: The goal of consciousness research is to reveal the neural basis of phenomenal experience. To study phenomenology, experimenters seem obliged to ask reports from the subjects to ascertain what they experience. However, we argue that the requirement of reports has biased the search for the neural correlates of consciousness over the past decades. More recent studies attempt to dissociate neural activity that gives rise to consciousness from the activity that enables the report in particular, no-report paradigms have been utilized to study conscious experience in the full absence of any report. We discuss the advantages and disadvantages of report-based and no-report paradigms, and ask how these jointly bring us closer to understanding the true neural basis of consciousness.
Attentional modulation of visual motion perception using novel wavelet stimuli
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 14-03-2010
DOI: 10.1167/1.3.84
Reasonable criteria for functionalists; scarce criteria from phenomenological perspective
Publisher: Informa UK Limited
Date: 06-12-2020
Optokinetic nystagmus reflects perceptual directions in the onset binocular rivalry in Parkinson's disease
Publisher: Public Library of Science (PLoS)
Date: 13-03-2017
Blocking facial mimicry during binocular rivalry modulates visual awareness of faces with a neutral expression
Publisher: Springer Science and Business Media LLC
Date: 11-05-2021
DOI: 10.1038/S41598-021-89355-5
Abstract: Several previous studies have interfered with the observer’s facial mimicry during a variety of facial expression recognition tasks providing evidence in favor of the role of facial mimicry and sensorimotor activity in emotion processing. In this theoretical context, a particularly intriguing facet has been neglected, namely whether blocking facial mimicry modulates conscious perception of facial expressions of emotions. To address this issue, we used a binocular rivalry paradigm, in which two dissimilar stimuli presented to the two eyes alternatingly dominate conscious perception. On each trial, female participants (N = 32) were exposed to a rivalrous pair of a neutral and a happy expression of the same in idual through anaglyph glasses in two conditions: in one, they could freely use their facial mimicry, in the other they had to keep a chopstick between their lips, constraining the mobility of the zygomatic muscle and producing ‘noise’ for sensorimotor simulation. We found that blocking facial mimicry affected the perceptual dominance in terms of cumulative time favoring neutral faces, but it did not change the time before the first dominance was established. Taken together, our results open a door to future investigation of the intersection between sensorimotor simulation models and conscious perception of emotional facial expressions.
Expectation and attention increase the integration of top-down and bottom-up signals in perception through different pathways
Publisher: Cold Spring Harbor Laboratory
Date: 18-10-2018
DOI: 10.1101/446948
Abstract: Perception results from the integration of incoming sensory information with pre-existing information available in the brain. In this EEG (electroencephalography) study we utilised the Hierarchical Frequency Tagging method to examine how such integration is modulated by expectation and attention. Using intermodulation (IM) components as a measure of non-linear signal integration, we show in three different experiments that both expectation and attention enhance integration between top-down and bottom-up signals. Based on multispectral phase coherence, we present two direct physiological measures to demonstrate the distinct yet related mechanisms of expectation and attention. Specifically, our results link expectation to the modulation of prediction signals and the integration of top-down and bottom-up information at lower levels of the visual hierarchy. Meanwhile, they link attention to the propagation of ascending signals and the integration of information at higher levels of the visual hierarchy. These results are consistent with the predictive coding account of perception.
Processing of Facial Emotion in the Human Fusiform Gyrus
Publisher: MIT Press - Journals
Date: 06-2012
DOI: 10.1162/JOCN_A_00175
Abstract: Electrophysiological and fMRI-based investigations of the ventral temporal cortex of primates provide strong support for regional specialization for the processing of faces. These responses are most frequently found in or near the fusiform gyrus, but there is substantial variability in their anatomical location and response properties. An outstanding question is the extent to which ventral temporal cortex participates in processing dynamic, expressive aspects of faces, a function usually attributed to regions near the superior temporal cortex. Here, we investigated these issues through intracranial recordings from eight human surgical patients. We compared several different aspects of face processing (static and dynamic faces happy, neutral, and fearful expressions) with power in the high-gamma band (70–150 Hz) from a spectral analysis. Detailed mapping of the response characteristics as a function of anatomical location was conducted in relation to the gyral and sulcal pattern on each patient's brain. The results document responses with high responsiveness for static or dynamic faces, often showing abrupt changes in response properties between spatially close recording sites and idiosyncratic across different subjects. Notably, strong responses to dynamic facial expressions can be found in the fusiform gyrus, just as can responses to static faces. The findings suggest a more complex, fragmented architecture of ventral temporal cortex around the fusiform gyrus, one that includes focal regions of cortex that appear relatively specialized for either static or dynamic aspects of faces.
Blocking facial mimicry during binocular rivalry modulates visual awareness of faces with a neutral expression
Publisher: Center for Open Science
Date: 17-06-2020
Abstract: Several previous studies have interfered with the observer’s facial mimicry during a variety of facial expression recognition tasks providing evidence in favor of the role of facial mimicry and sensorimotor activity in emotion processing. In this theoretical context, a particularly intriguing facet has been neglected, namely whether blocking facial mimicry modulates conscious perception of facial expressions of emotions. To address this issue, we used a binocular rivalry paradigm, in which two dissimilar stimuli presented to the two eyes alternatingly dominate conscious perception. On each trial, female participants (N = 32) were exposed to a rivalrous pair of a neutral and a happy expression of the same in idual through anaglyph glasses in two conditions: in one, they could freely use their facial mimicry, in the other they had to keep a chopstick between their lips, constraining the mobility of the zygomatic muscle and producing ‘noise’ for sensorimotor simulation. We found that blocking facial mimicry affected the mean duration of perceptual dominance favoring neutral faces, but it did not change the time before the first dominance was established. Taken together, our results open a door to future investigation of the intersection between sensorimotor simulation models and conscious perception of emotional facial expressions.
A Quantum Geometric Framework for Modeling Color Similarity Judgements
Publisher: Center for Open Science
Date: 15-12-2021
Abstract: Since Tversky (1977) argued that similarity judgments violate the three metric axioms, asymmetrical similarity judgments have been offered as particularly difficult challenges for standard, geometric models of similarity, such as multidimensional scaling. According to Tversky (1977), asymmetrical similarity judgments are driven by differences in salience or extent of knowledge. However, the notion of salience has been difficult to operationalize to different kinds of stimuli, especially perceptual stimuli for which there are no apparent differences in extent of knowledge. To investigate similarity judgments between perceptual stimuli, across three experiments we collected data where in iduals would rate the similarity of a pair of temporally separated color patches. We identified several violations of symmetry in the empirical results, which the conventional multidimensional scaling model cannot readily capture. Pothos et al. (2013) proposed a quantum geometric model of similarity to account for Tversky’s (1977) findings. In the present work, we extended this model to a more general framework that can be fit to similarity judgments. We fit several variants of quantum and multidimensional scaling models to the behavioral data and concluded in favor of the quantum approach. Without further modifications of the model, the best-fit quantum model additionally predicted violations of the triangle inequality that we observed in the same data. Overall, by offering a different form of geometric representation, the quantum geometric framework of similarity provides a viable alternative to multidimensional scaling for modeling similarity judgments, while still allowing a convenient, spatial illustration of similarity.
Sustained conscious access to incidental memories in RSVP
Publisher: Center for Open Science
Date: 27-04-2018
Abstract: In visual search of natural scenes, differentiation of briefly fixated but task-irrelevant distractor items from incidental memory is often comparable to explicit memorization. However, many characteristics of incidental memory remain unclear, including the capacity for its conscious retrieval. Here, we examined incidental memory for faces in either upright or inverted orientation using Rapid Serial Visual Presentation (RSVP). Subjects were instructed to detect a target face in a sequence of 8-15 faces cropped from natural scene photographs (Experiment 1). If the target face was identified within a brief time window, the subject proceeded to an incidental memory task. Here, subjects used incidental memory to discriminate between a probe face (a distractor in the RSVP stream) and a novel, foil face. In Experiment 2 we reduced scene-related semantic coherency by intermixing faces from multiple scenes and contrasted incidental memory with explicit memory a condition where subjects actively memorised each face from the sequence without searching for a target. In both experiments, we measured objective performance (Type 1 AUC) and metacognitive accuracy (Type 2 AUC) revealing sustained and consciously accessible incidental memory for upright and inverted faces. In novel analyses of face categories, we examined whether accuracy or metacognitive judgements are affected by shared semantic features (i.e., similarity in gender, race, age). Similarity enhanced the accuracy of incidental memory discriminations but did not influence metacognition. We conclude that incidental memory is sustained and consciously accessible, is not reliant on scene contexts, and not enhanced by explicit memorization.
Motion-Induced Blindness as a Tool to Measure Attentional Biases and the Link to Attention-Deficit/Hyperactivity Traits
Publisher: Center for Open Science
Date: 20-09-2018
Abstract: Typically, in iduals have an attentional bias towards the left visual field. This is often absent in in iduals with attention-deficit/hyperactivity (ADH) disorder (ADHD). We used a motion-induced blindness task with targets in four quadrants in order to assess left/right as well as upper/lower spatial biases in perceptual disappearances, and also measured changes in the disappearances with time-on-task. Fifty-eight university students (41 female) completed the Conners Adult ADHD self-report short-form to assess the number of ADH traits, and 48 trials of a one-minute motion-induced blindness (MIB) task. Through a hybrid hypothesis-driven and data-driven analysis approach, we found that the MIB illusion increased with more ADH traits, decreased with time-on-task, and was stronger for left and lower quadrants. The time-on-task likely contributed to the strength of the illusion through changes in arousal, as pupil size decreased with time-on-trial in a subset of participant (n=11) for who we measure eye-movements. Additionally, whilst participants were biased towards the lower left visual field, this was, unexpectedly, most prominent with those with higher ADH traits. This novel result suggests an additive effect of left/right and upper/lower spatial biases. Taken together, this study supports an association between spatial attention, arousal and ADH traits in MIB.
Depth of interocular suppression associated with continuous flash suppression, flash suppression, and binocular rivalry
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 21-09-2006
DOI: 10.1167/6.10.6
Separating weak integrated information theory (IIT) into IIT-inspired and aspirational-IIT approaches
Publisher: Center for Open Science
Date: 15-01-2023
Abstract: Mediano et al. (1. Mediano 2022 TICS) separate out strong and weak flavours of the integrated information theory (IIT) of consciousness. They describe “strong IIT” as attempting to derive a universal formula for consciousness, and “weak IIT” as searching for empirically measurable correlates of aspects of consciousness. We put forward that their overall notion of “weak IIT” may be too weak. Rather, it should be separated out to distinguish “aspirational IIT”, which aims to empirically test IIT by making tradeoffs to its proposed measures, and “IIT inspired” approaches, which adopt high level ideas of IIT while dropping the mathematical framework it reaches through its introspective, first-principles approach to consciousness.
Orienting to social stimuli differentiates social cognitive impairment in autism and schizophrenia
Publisher: Elsevier BV
Date: 2007
Divided attention in the tactile modality
Publisher: Springer Science and Business Media LLC
Date: 19-10-2021
Conscious perception of flickering stimuli in binocular rivalry and continuous flash suppression is not affected by tACS-induced SSR modulation
Publisher: Elsevier BV
Date: 07-2020
Evidence accumulation clustering using combinations of features
Publisher: Elsevier BV
Date: 2020
Third-Eye Rivalry
Publisher: SAGE Publications
Date: 07-2020
Abstract: We showcase an optical phenomenon that we call Third-Eye Rivalry. The effect is most easily induced by viewing one’s own reflection in a mirror. Using the pupil of the opposing eye as a fixation target, people can easily cross their eyes in free fusion to experience vivid rivalry. The resulting percept is of a prominent central “third” eye and two peripheral faces rivaling for perceptual dominance. We illustrate the process of achieving third-eye rivalry and discuss historical connotations of the third eye in scientific and mystical contexts.
Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain
Publisher: Society for Neuroscience
Date: 07-2016
DOI: 10.1523/ENEURO.0116-16.2016
Abstract: What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly ( Drosophila melanogaster ). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli (‘frequency tags’) allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain.
List of Contributors
Publisher: Elsevier
Date: 2009
Attention and consciousness
Publisher: Scholarpedia
Date: 2008
Information flow in the rat thalamo-cortical system: spontaneous vs. stimulus-evoked activities
Publisher: Springer Science and Business Media LLC
Date: 28-09-2021
DOI: 10.1038/S41598-021-98660-Y
Abstract: The interaction between the thalamus and sensory cortex plays critical roles in sensory processing. Previous studies have revealed pathway-specific synaptic properties of thalamo-cortical connections. However, few studies to date have investigated how each pathway routes moment-to-moment information. Here, we simultaneously recorded neural activity in the auditory thalamus (or ventral ision of the medial geniculate body MGv) and primary auditory cortex (A1) with a laminar resolution in anesthetized rats. Transfer entropy (TE) was used as an information theoretic measure to operationalize “information flow”. Our analyses confirmed that communication between the thalamus and cortex was strengthened during presentation of auditory stimuli. In the resting state, thalamo-cortical communications almost disappeared, whereas intracortical communications were strengthened. The predominant source of information was the MGv at the onset of stimulus presentation and layer 5 during spontaneous activity. In turn, MGv was the major recipient of information from layer 6. TE suggested that a small but significant population of MGv-to-A1 pairs was “information-bearing,” whereas A1-to-MGv pairs typically exhibiting small effects played modulatory roles. These results highlight the capability of TE analyses to unlock novel avenues for bridging the gap between well-established anatomical knowledge of canonical microcircuits and physiological correlates via the concept of dynamic information flow.
A Quantum Qualia hypothesis: from Quantum Cognition to Quantum Perception
Publisher: Center for Open Science
Date: 02-06-2023
Abstract: To arbitrate theories of consciousness, scientists need mathematical models of consciousness or qualia. The dominant view regards qualia as points in a dimensional space. Implicit in this view is that qualia can be in principle measured without any effects on it. This contrasts with intuitions and various empirical findings about qualia that they can change when they are measured. How can we deal with entities that are affected by the act of measurement? We argue that mathematical formalisms of quantum theory are precisely developed to deal with such situations. Here, we propose qualia as “observables” (i.e., entities that can be in principle observed), sensory inputs and internal attention as “states” that specify the context that a measurement takes place, and “measurement outcomes” as expected values of qualia observables in a certain state. We propose to call this formalism as the Quantum Qualia (QQ) hypothesis. QQ proposes that qualia observables in a state interact with the world, as if through an interface of sensory inputs and internal attention. This qualia-interface-world scheme has the same mathematical structure as observables-states-environment in quantum theory. Within this framework, mathematical concepts of “instruments” can precisely formalize how measurements can affect (or update) qualia observables and states. QQ naturally explains intuitions about qualia, such as the nature of qualia as indeterminate entities. Finally, QQ leads to empirical predictions that challenge traditional models, such as order effects and violations of Bell inequalities. With further confirmation of such predictions, we believe that QQ will emerge as a viable alternate mathematical model of qualia, offering an important step towards understanding the nature and structures of consciousness.
Is my red your red?: Unsupervised alignment of qualia structures via optimal transport
Publisher: Center for Open Science
Date: 07-01-2023
Abstract: To what extent are sensory experiences equivalent between in iduals? One promising approach to this fundamental question about consciousness is to intersubjectively compare the similarity relationships of sensory experiences, named "qualia structures". Conventional methods for comparing the similarity relationships largely sidestep the issue by assuming experiences evoked by the same stimuli are matched across in iduals, precluding the possibility that my "red" might be your "blue". Here, we present an unsupervised optimal transport method for assessing the similarity of qualia structures without assuming correspondence between in iduals. As proof of concept, we analyzed two massive datasets: dissimilarity judgments for 93 colors and 1854 natural objects. In both cases, we found that qualia structures can be "correctly" aligned across participants based solely on similarity relationships, providing quantitative evidence for the structural equivalence of qualia of color and natural objects across in iduals. This method is applicable to any modality of experience, enabling general structural exploration of subjective experiences.
Preferential attention to animals and people is independent of the amygdala
Publisher: Oxford University Press (OUP)
Date: 05-2014
DOI: 10.1093/SCAN/NSU065
An adjunction hypothesis between qualia and reports
Publisher: Frontiers Media SA
Date: 30-01-2023
DOI: 10.3389/FPSYG.2022.1053977
Abstract: What are the nature of the relationship among qualia, contents of consciousness, and behavioral reports? Traditionally, this type of question has been only addressed via a qualitative and philosophical approach. Some theorists emphasize an incomplete and inaccurate nature of reports of one's own qualia to discourage formal research programs on qualia. Other empirical researchers, however, have made substantial progress in understanding the structure of qualia from such limited reports. What is the precise relationship between the two? To answer this question, we introduce the concept of “adjoint” or “adjunction” from the category theory in mathematics. We claim that the adjunction captures some aspects of the nuanced relationships between qualia and reports. The concept of adjunction allows us to clarify the conceptual issues with a precise mathematical formulation. In particular, adjunction establishes coherence between two categories that cannot be considered equivalent, yet has an important relationship. This rises in empirical experimental situations between qualia and reports. More importantly, an idea of adjunction naturally leads to various proposals of new empirical experiments to test the predictions about the nature of their relationship as well as other issues in consciousness research.
Integrated information structure collapses with anesthetic loss of conscious arousal in Drosophila melanogaster
Publisher: Cold Spring Harbor Laboratory
Date: 19-05-2020
DOI: 10.1101/2020.05.17.090001
Abstract: The physical basis of consciousness remains one of the most elusive concepts in current science. One influential conjecture is that consciousness is to do with some form of causality, measurable through information. The integrated information theory of consciousness (IIT) proposes that conscious experience, filled with rich and specific content, corresponds directly to a hierarchically organised, irreducible pattern of causal interactions i.e. an integrated informational structure among elements of a system. Here, we tested this conjecture in a simple biological system (fruit flies), estimating the information structure of the system during wakefulness and general anesthesia. Consistent with this conjecture, we found that integrated interactions among populations of neurons during wakefulness collapsed to isolated clusters of interactions during anesthesia. We used classification analysis to quantify the accuracy of discrimination between wakeful and anesthetised states, and found that informational structures inferred conscious states with greater accuracy than a scalar summary of the structure, a measure which is generally ch ioned as the main measure of IIT. In stark contrast to a view which assumes feedforward architecture for insect brains, especially fly visual systems, we found rich information structures, which cannot arise from purely feedforward systems, occurred across the fly brain. Further, these information structures collapsed uniformly across the brain during anesthesia. Our results speak to the potential utility of the novel concept of an “informational structure” as a measure for level of consciousness, above and beyond simple scalar values. The physical basis of consciousness remains elusive. Efforts to measure consciousness have generally been restricted to simple, scalar quantities which summarise the complexity of a system, inspired by integrated information theory, which links a multi-dimensional, informational structure to the contents of experience in a system. Due to the complexity of the definition of the structure, assessment of its utility as a measure of conscious arousal in a system has largely been ignored. In this manuscript we evaluate the utility of such an information structure in measuring the level of arousal in the fruit fly. Our results indicate that this structure can be more informative about the level of arousal in a system than even the single-value summary proposed by the theory itself. These results may push consciousness research towards the notion of multi-dimensional informational structures, instead of traditional scalar summaries.
Emergence of Integrated Information at Macro Timescales in Real Neural Recordings
Publisher: MDPI AG
Date: 29-04-2022
DOI: 10.3390/E24050625
Abstract: How a system generates conscious experience remains an elusive question. One approach towards answering this is to consider the information available in the system from the perspective of the system itself. Integrated information theory (IIT) proposes a measure to capture this integrated information (Φ). While Φ can be computed at any spatiotemporal scale, IIT posits that it be applied at the scale at which the measure is maximised. Importantly, Φ in conscious systems should emerge to be maximal not at the smallest spatiotemporal scale, but at some macro scale where system elements or timesteps are grouped into larger elements or timesteps. Emergence in this sense has been demonstrated in simple ex le systems composed of logic gates, but it remains unclear whether it occurs in real neural recordings which are generally continuous and noisy. Here we first utilise a computational model to confirm that Φ becomes maximal at the temporal scales underlying its generative mechanisms. Second, we search for emergence in local field potentials from the fly brain recorded during wakefulness and anaesthesia, finding that normalised Φ (wake/anaesthesia), but not raw Φ values, peaks at 5 ms. Lastly, we extend our model to investigate why raw Φ values themselves did not peak. This work extends the application of Φ to simple artificial systems consisting of logic gates towards searching for emergence of a macro spatiotemporal scale in real neural systems.
What can we experience and report on a rapidly presented image? Intersubjective measures of specificity of freely reported contents of consciousness
Publisher: Center for Open Science
Date: 07-10-2021
Abstract: Previous studies have established a view that human observers can only perceive coarse information from a natural scene image when it is presented rapidly (& ms, masked). In these studies, participants were often forced to choose an answer from options that experimenters preselected. These options can underestimate what participants experience and can report on it. Here, we used a novel free-report paradigm to examine what people can freely report following a rapidly presented natural scene image (67/133/267ms, masked). N = 670 online participants typed up to five words to report what they saw in the image together with confidence of the respective responses. We developed a novel index, Intersubjective Agreement (IA). IA quantifies how specifically the response words were used to describe the target image, with a high value meaning the word is not often reported for other images. IA eliminates the need for experimenters to preselect response options. With IA, unlike commonly believed, we demonstrated that participants reported highly specific and detailed aspects of the briefly (even at 67ms, masked) shown image. Further, IA is positively correlated with confidence, indicating metacognitive conscious access to the reported aspects of the image. These new findings challenge the dominant view that the content of rapid scene experience is limited to global and coarse gist. Our novel paradigm opens a door to investigate various contents of consciousness with a free-report paradigm.
No-Report and Report-Based Paradigms Jointly Unravel the NCC: Response to Overgaard and Fazekas
Publisher: Elsevier BV
Date: 04-2016
Conscious access in the near absence of attention: Critical extensions on the dual-task paradigm
Publisher: Center for Open Science
Date: 22-08-2017
Abstract: Whether conscious perception requires attention remains a topic of intense debate. While certain complex stimuli such as faces and animals can be discriminated outside the focus of spatial attention, many simpler stimuli cannot. Because such evidence was obtained in dual-task paradigms involving no measure of subjective insight, it remains unclear whether accurate discrimination of unattended complex stimuli is the product of automatic, unconscious processing, as in blindsight, or is accessible to consciousness. Furthermore, these paradigms typically require extensive training over many hours, bringing into question whether this phenomenon can be achieved in naive subjects. We developed a novel dual-task paradigm incorporating confidence ratings to calculate metacognition and adaptive staircase procedures to reduce training. With minimal training, subjects were able to discriminate face-gender despite little or no top-down attentional lification, while also displaying above-chance metacognitive accuracy. In contrast, the discrimination of simple coloured disks was significantly impaired and metacognitive accuracy collapsed, even in a partial-report condition. In a final experiment we used blended face/disk stimuli and confirmed that face-gender but not colour orientation can be discriminated in the dual-task. Our results show direct evidence for metacognitive conscious access in the near absence of attention for complex, but not simple, stimuli.
A general spectral decomposition of causal influences applied to integrated information
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.JNEUMETH.2019.108443
Abstract: Quantifying interactions among many neurons is fundamental to understanding system-level phenomena such as attention, learning and even conscious experience. Causal influences in the brain, quantified as integrated information, are thought to support subjective conscious experience. Recent empirical work has shown that the spectral decomposition of causal influences, for ex le using Granger causality, can reveal frequency-specific influences that are not observed in the time domain. However, a spectral decomposition of integrated information has not been put forward, limiting its adoption for analyzing neural data. We present a general and flexible framework for deriving the spectral decomposition of causal influences in autoregressive processes. We use the framework to derive a spectral decomposition of integrated information. We show that other well-known measures, including Granger causality, can be derived using the same framework. Using simulations, we demonstrate a complex interplay between the spectral decomposition of integrated information and other measures that is not observed in the time domain. This paper provides a spectral decomposition of integrated information for the first time. Although a spectral decomposition of Granger causality has been derived, that approach is only applicable to uni-directional causal influences, not multi-directional causal influences as required for integrated information. Our novel framework can be used to derive the spectral decomposition of uni- and multi-directional measures of causal influences. We use this framework to derive a spectral decomposition of integrated information, paving the way for better understanding how frequency-specific causal influences in the brain relate to cognition.
How much can we differentiate at a brief glance: revealing the truer limit in conscious contents through the massive report paradigm (MRP)
Publisher: The Royal Society
Date: 05-2022
DOI: 10.1098/RSOS.210394
Abstract: Upon a brief glance, how well can we differentiate what we see from what we do not? Previous studies answered this question as ‘poorly’. This is in stark contrast with our everyday experience. Here, we consider the possibility that previous restriction in stimulus variability and response alternatives reduced what participants could express from what they consciously experienced. We introduce a novel massive report paradigm that probes the ability to differentiate what we see from what we do not. In each trial, participants viewed a natural scene image and judged whether a small image patch was a part of the original image. To examine the limit of discriminability, we also included subtler changes in the image as modification of objects. Neither the images nor patches were repeated per participant. Our results showed that participants were highly accurate (accuracy greater than 80%) in differentiating patches from the viewed images from patches that are not present. Additionally, the differentiation between original and modified objects was influenced by object sizes and/or the congruence between objects and the scene gists. Our massive report paradigm opens a door to quantitatively measure the limit of immense informativeness of a moment of consciousness.
Beyond the “Neural Correlates of Consciousness”: Characterizing the structure of consciousness and information and identifying their relationship
Publisher: Center for Open Science
Date: 15-01-2020
Abstract: 我々が主観的に感じる意識と、脳の中で生じている物理・化学現象の間をつなぐ科学法則とは一体どのようなものだろうか？ 意識をめぐる謎は、現代科学が直面している謎の中でも最も巨大でかつ魅惑的なものの一つである。この謎を避け、人間や動物を外部から観測可能な行動のみから規定しようとする世界観では、幻覚・妄想などを訴える患者の意識の理解、さらには、言語報告のできない患者・乳児・動物の主観感覚の理解といった問題に、科学的なメスを入れることができない。近年、そのような世界観を乗り越え、意識の問題に真っ向から取り込もうとする科学者が中心となり、意識と脳の関係性を巡る実証的研究が大幅に進んできた。本稿では、現状見込みがあると考えられている意識研究のいくつかの研究の枠組みを概観する。さらに、従来の枠組みでは乗り越えるのが難しい意識の問題を解決するために、著者らが近年考えている方策を紹介する。著者らは意識経験の構造、さらに脳から生じる情報の構造、そして構造の間の関係性を明らかにする必要性があると考えている。本稿ではそれを可能にする数学的ツール、圏論も簡単に紹介し、今後の展望を述べる。
Unconscious Visual Working Memory: a critical review and Bayesian meta-analysis
Publisher: Center for Open Science
Date: 10-10-2021
Abstract: The relationship between consciousness and working memory (WM) has been recently debated both at the theoretical and methodological levels (Persuh et al., 2018 Velichkovsky, 2017). While there is behavioral and neural evidence that argues for the existence of unconscious WM, several methodological concerns have been raised, rendering this issue highly controversial. To address the robustness of the previous findings, here we adopt a meta-analytic approach to estimate the effect size and heterogeneity of the previously reported unconscious WM results, also including unpublished results. We used meta-regression to isolate relevant experimental variables, in particular, consciousness manipulation and WM paradigm to identify the source of the heterogeneity in the reported effect size of the unconscious WM. Our meta-analysis supports the existence of the unconscious WM effect and critically reveals several experimental variables that contribute to relevant heterogeneity. Our analysis clarifies several theoretical and methodological issues. We recommend that future studies explicitly operationalize the definition of consciousness, standardize the methodology and systematically explore the role of critical variables for the unconscious WM effect.
Expectation and attention increase the integration of top-down and bottom-up signals in perception through different pathways
Publisher: Public Library of Science (PLoS)
Date: 30-04-2019
Related Organisations
California Institute Of Technology
Location: United States of America
Related Funding Activities
Discovery Projects - Grant ID: DP180100396
Start Date: 07-2018
End Date: 07-2021
Amount: $314,286.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP130100194
Start Date: 2013
End Date: 12-2015
Amount: $489,000.00
Funder: Australian Research Council
View Funded ActivityARC Future Fellowships - Grant ID: FT120100619
Start Date: 10-2012
End Date: 07-2018
Amount: $714,513.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP180104128
Start Date: 03-2018
End Date: 12-2021
Amount: $414,792.00
Funder: Australian Research Council
View Funded Activity