Jacqueline Rushby

Probabilistic association learning in frontotemporal dementia and schizophrenia

Publisher: Elsevier BV

Date: 2013

DOI: 10.1016/J.CORTEX.2011.09.011

Abstract: Recent neuropsychological studies show substantial cognitive deficits in patients with frontotemporal dementia (FTD). Schizophrenia (SC) overlaps in terms of neurobehavioural symptoms with FTD. Probabilistic association learning, which is thought to assay fronto-striatal function, is well documented to elicit impairment in SC and has not been investigated in FTD to date this study compared FTD, SC and a healthy comparison group on probabilistic association learning to determine the extent to which FTD patients were similar in performance to SC patients. Twenty FTD patients, 24 SC patients and 26 healthy controls were assessed using the probabilistic association learning weather prediction test. FTD patients were also ided into behavioural and language variants for comparison to the healthy group. FTD patients were impaired during probabilistic association learning in comparison to healthy controls. There was no difference in performance between the FTD and SC groups. FTD behavioural variants performed significantly worse than the healthy comparison group, while FTD language variants did not differ from the healthy comparison group. This study provides the first evidence for impaired probabilistic association learning in FTD which is of an equivalent degree to that seen in SC. These results support recent structural neuroimaging studies showing fronto-striatal abnormalities in FTD and suggest that fronto-striatal dysfunction may contribute to cognitive deficits in a significant proportion of people with FTD.

Arousal and activation in a continuous performance task: An exploration of state effects in normal children

Publisher: Hogrefe Publishing Group

Date: 2005

DOI: 10.1027/0269-8803.19.2.91

Abstract: Abstract: The concepts of arousal and activation have had a confused history in Psychophysiology, and there is no widely accepted consensus on their usefulness in the field. This study aimed to explore whether these concepts could be separated in terms of their effects on the phasic Orienting Response (OR) and behavioral performance. We defined arousal at a particular time to be the energetic state at that time, reflected in electrodermal activity and measured by skin conductance level. Task-related activation was defined as the change in arousal from a resting baseline to the task situation. A continuous performance task was used with normal children. The magnitude of the mean phasic OR elicited by target stimuli was dependent on arousal, but not on task-related activation. Two performance measures (mean reaction time and number of errors) improved with increasing activation, but not with arousal. These data suggest the value of conceptualizing arousal and activation as separable aspects of the energetics of physiological and behavioral responding in future studies of attention, cognition, and emotion.

Caffeine effects on resting-state arousal

Publisher: Elsevier BV

Date: 11-2005

DOI: 10.1016/J.CLINPH.2005.08.008

Abstract: This study examined the use of caffeine to manipulate arousal level without the confounds associated with task-related activation. From previous work in our laboratory, an increase in skin conductance level (SCL) and EEG alpha frequency, together with a global decrease in alpha power, were used as markers of arousal increase, and we sought to identify these effects with caffeine ingestion. We examined the effect of a single oral dose of caffeine (250 mg) in a randomised double-blind placebo-controlled repeated-measures cross-over study. Eighteen healthy university students (mean age 21 years 13/18 females) participated in two sessions 1 week apart. EEG and autonomic data (SCL, heart rate, systolic and diastolic blood pressure, and respiration rate) from a 2 min eyes-closed epoch, commencing approximately 30 min after ingestion of caffeine or placebo, were examined. Caffeine was associated with increased SCL, a global reduction in EEG power in the alpha band, and a global increase in alpha frequency. There were no cardiovascular effects. The positive results are consistent with recent electrodermal and EEG studies of arousal and suggest that caffeine may be utilised as a task-free means of manipulating arousal in future investigations. Further work is necessary to clarify the absence of cardiovascular effects, and to integrate those data with emerging conceptualisations of arousal and activation. The present data support the use of caffeine as a simple tool to explore the role of arousal in both normal and atypical functioning, and this may be useful in determining the validity and importance of supposed hyper- or hypo-arousal in such syndromes as attention-deficit/hyperactivity disorder (AD/HD).

Target-to-target interval, intensity, and P300 from an auditory single-stimulus task

Publisher: Wiley

Date: 07-02-2007

DOI: 10.1111/J.1469-8986.2007.00495.X

Abstract: Target-to-target interval (TTI) is a primary determinant of P300 litude, such that longer TTIs yield larger components than shorter intervals. Systematic manipulations of TTI affect component litude, latency, and associated response time in a fashion that suggests that the template update hypothesis can account for these outcomes. The present study examines whether manipulations of TTI (from 1 to 16 s) and stimulus intensity (soft and loud tones) produce outcomes consistent with this hypothesis. A single-stimulus task was employed in which only target stimuli were presented. P300 litude increased, peak latency decreased, and response time increased as TTI became longer, with less effect for soft compared to loud stimulus conditions on P300 litude at Pz. TTI increases also augmented N100 litude, with consistently smaller litudes obtained for soft relative to loud stimuli. Overall, P300 measures are sensitive to both temporal and physical stimulus factors. Theoretical implications are discussed.

Psychophysiology in Australasia. Selected papers from the 22nd Annual Meeting of the Australasian Society for Psychophysiology, ASP2012, held at the University of New South Wales, Sydney, Australia, 28-30 November 2012.

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.IJPSYCHO.2013.08.004

Automatic facial responses to briefly presented emotional stimuli in autism spectrum disorder

Publisher: Elsevier BV

Date: 10-2013

DOI: 10.1016/J.BIOPSYCHO.2013.08.004

Abstract: Emotion processing, including automatic facial mimicry, plays an important role in social reciprocity. Disruptions in these processes have implications for in iduals with impaired social functioning, such as autism spectrum disorders (ASDs). Past research has demonstrated that ASDs are impaired in the recognition of briefly presented emotions and display atypical mimicry of emotions presented for protracted duration. Mimicry (electromyography EMG) of briefly presented emotions was investigated in adults with ASDs. Concurrent measures of skin conductance and cardiac responses were used as markers of orientation and stimulus detection, respectively. A backward masking task was employed whereby the emotional face (happy, angry) was presented for 30 ms followed by a neutral face "mask". An implicit comparison task required rapid gender identification. The ASD group failed to differentiate by valence in their EMG (zygomaticus, corrugator) and demonstrated atypical pre- and post-stimulus arousal. These findings may provide a potential mechanism for marked deficits in social reciprocity.

Loss of white matter connections after severe traumatic brain injury (TBI) and its relationship to social cognition

Publisher: Springer Science and Business Media LLC

Date: 14-06-2018

DOI: 10.1007/S11682-018-9906-0

Abstract: Adults with severe traumatic brain injury (TBI) often suffer poor social cognition. Social cognition is complex, requiring verbal, non-verbal, auditory, visual and affective input and integration. While damage to focal temporal and frontal areas has been implicated in disorders of social cognition after TBI, the role of white matter pathology has not been examined. In this study 17 adults with chronic, severe TBI and 17 control participants underwent structural MRI scans and Diffusion Tensor Imaging. The Awareness of Social Inference Test (TASIT) was used to assess their ability to understand emotional states, thoughts, intentions and conversational meaning in everyday exchanges. Track-based spatial statistics were used to perform voxelwise analysis of Fractional Anisotropy (FA) and Mean Diffusivity (MD) of white matter tracts associated with poor social cognitive performance. FA suggested a wide range of tracts were implicated in poor TASIT performance including tracts known to mediate, auditory localisation (planum temporale) communication between nonverbal and verbal processes in general (corpus callosum) and in memory in particular (fornix) as well as tracts and structures associated with semantics and verbal recall (left temporal lobe and hippoc us), multimodal processing and integration (thalamus, external capsule, cerebellum) and with social cognition (orbitofrontal cortex, frontopolar cortex, right temporal lobe). Even when controlling for non-social cognition, the corpus callosum, fornix, bilateral thalamus, right external capsule and right temporal lobe remained significant contributors to social cognitive performance. This study highlights the importance of loss of white matter connectivity in producing complex social information processing deficits after TBI.

Why don’t you feel how I feel? Insight into the absence of empathy after severe Traumatic Brain Injury

Publisher: Elsevier BV

Date: 10-2010

DOI: 10.1016/J.NEUROPSYCHOLOGIA.2010.08.008

Abstract: Although the existence of empathy deficits in people with traumatic brain injury (TBI) is generally well accepted, it has been a topic of limited investigation. The current study examined the relationship between self-reported emotional and cognitive empathy and psychophysiological responding to emotionally evocative pictures in 20 patients with severe TBI and 22 control participants. Eighteen pictures with alternating pleasant, unpleasant and neutral content selected from the International Affective Picture System (IAPS) were presented whilst facial muscle responses, skin conductance, and valence and arousal ratings were measured. Self-reported emotional and cognitive empathy questionnaires were also administered. In comparison to control participants, those in the TBI group displayed a reduction in the ability to empathize both emotionally and cognitively, and evidence that these two aspects of empathy may be interconnected was established. Further, TBI participants showed reduced facial responding to unpleasant pictures, while also rating them as less unpleasant and arousing than controls. In addition, they exhibited lowered autonomic arousal to all pictures, regardless of affective valence. Interestingly, hypoarousal to pleasant pictures in particular was found to be related to the absence of empathy observed after TBI, and is consistent with the view that impaired emotional responsivity is associated with impairment to the empathy network. The results represent a further step towards understanding what processes shape empathy.

Brain dynamics in the auditory Go/NoGo task as a function of EEG frequency

Publisher: Elsevier BV

Date: 11-2010

DOI: 10.1016/J.IJPSYCHO.2010.06.357

Abstract: We examined relationships between the phase of narrow-band electroencephalographic (EEG) activity at stimulus onset and the resultant event-related potentials (ERPs) in an equiprobable auditory Go/NoGo task with a fixed SOA, in the context of a novel conceptualisation of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). ERP responses to each stimulus type were analysed. Prestimulus narrow-band EEG activity (in 1Hz bands from 1 to 13Hz) at Cz was assessed for each trial using FFT decomposition of the EEG data. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from the raw EEG activity at 9 central sites. The occurrence of preferred phase-defined brain states was confirmed at a number of frequencies, crossing the traditional frequency bands. As expected, these did not differ between Go and NoGo stimuli. These preferred states were associated with more efficient processing of the stimulus, as reflected in differences in latency and litude of the N1 and P3 ERP components. The present results, although derived in a different paradigm by EEG decomposition methods different from those used previously, confirm the existence of preferred brain states and their impact on the efficiency of brain dynamics involved in perceptual and cognitive processing.

Facial expressiveness and physiological arousal in frontotemporal dementia: Phenotypic clinical profiles and neural correlates

Publisher: Springer Science and Business Media LLC

Date: 28-11-2019

DOI: 10.3758/S13415-018-00658-Z

Abstract: Early theories of emotion processing propose an interplay between autonomic function and cognitive appraisal of emotions. Patients with frontotemporal dementia show profound social cognition deficits and atrophy in regions implicated in autonomic emotional responses (insula, amygdala, prefrontal cortex), yet objective measures of facial expressiveness and physiological arousal have been relatively unexplored. We investigated psychophysiological responses (surface facial electromyography (EMG) skin conductance level (SCL)) to emotional stimuli in 25 behavioural-variant frontotemporal dementia (bvFTD) patients, 14 semantic dementia (SD) patients, and 24 healthy older controls, while viewing emotionally positive, neutral, or negative video clips. Voxel-based morphometry was conducted to identify neural correlates of responses. Unlike controls, patients with bvFTD did not show differential facial EMG responses according to emotion condition, whereas SD patients showed increased zygomaticus responses to both positive and neutral videos. Controls showed greater arousal (SCL) when viewing positive and negative videos however, both bvFTD and SD groups showed no change in SCL across conditions. Regardless of group membership, right insula damage was associated with d ened zygomaticus responses to positive film stimuli. Change in arousal (SCL) was associated with lower integrity of the caudate, amygdala, and temporal pole. Our results demonstrate that while bvFTD patients show an overall d ening of responses, SD patients appear to show incongruous facial emotional expressions. Abnormal responding is related to cortical and subcortical brain atrophy. These results identify potential mechanisms for the abnormal social behaviour in bvFTD and SD and demonstrate that psychophysiological responses are an important mechanism underpinning normal socioemotional functioning.

Dynamics of narrow-band EEG phase effects in the passive auditory oddball task

Publisher: Wiley

Date: 07-2006

DOI: 10.1111/J.1460-9568.2006.04879.X

Abstract: Evidence suggests that the component frequencies of the electroencephalogram (EEG) are dynamically adjusted to provide particular brain states at stimulus occurrence, and that these facilitate cortical processing of the stimulus. We examined relationships between stimulus intensity, the phase of narrow-band EEG activity at stimulus onset, and the resultant event-related potentials (ERPs) in a passive auditory oddball task, using a novel conceptualization of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). EEG responses to the standard stimuli (50 vs. 80 dB, varied between subjects) were analysed. Prestimulus narrow-band EEG activity (in 1-Hz bands from 1 to 13 Hz) at Cz was assessed for each trial by digital filtering. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from both the filtered and unfiltered EEG activity at Fz, Cz and Pz. Preferred brain states at various frequencies were indicated by 16-34% differential occurrence within the orthogonal phase dimensions explored. The preferred states were associated with smaller N1, N2 and N3, larger P2 and P3, shorter N1, P2, N2 and P3 latencies, and some intensity effects. These effects reflected the operation of three separate phase-influenced mechanisms, involving anticipatory potentials and prestimulus oststimulus litudes in various EEG frequencies. Results indicate that, even in paradigms with a slightly varying interstimulus interval, brain dynamics provide preferred brain states at the moment of stimulus presentation, which differentially affect the EEG correlates of stimulus processing.

Event-related potential correlates of serial-position effects during an elaborative memory test

Publisher: Elsevier BV

Date: 10-2002

DOI: 10.1016/S0167-8760(02)00037-5

Abstract: Twenty undergraduate students participated in an elaborative learning test to evaluate the relationship between electrical brain activity and subsequently recalled and not-recalled words. Data collected from the midline (Fz, Cz, Pz) and lateral scalp sites (F3, F4, C3, C4, P3, P4) were analysed. The difference between event-related potentials (ERPs) elicited by subsequently recalled and not-recalled words, the ERP memory effect, was evaluated for each portion (primacy, plateau and recency) of the serial-position curve (SPC). We compared peak litudes for the P1, N1, P2, N400, P3 and frontal positive slow wave (FPSW) components. The electrophysiological data support the hypothesis that different mechanisms underlie primacy and recency effects during free recall paradigms. There was no support for the hypothesis that an association arises between memory and the FPSW when subjects utilise elaborative learning strategies. The P2 component predicted subsequent recall at the primacy portion of the SPC, and P1 predicted recall at the primacy and plateau portions of the curve. The findings suggest that the early positive components of the ERP (i.e. P1 and P2) are useful indices of the differential stimulus processing during elaborative learning which predicts later recall.

Separation of the components of the late positive complex in an ERP dishabituation paradigm

Publisher: Elsevier BV

Date: 10-2005

DOI: 10.1016/J.CLINPH.2005.06.008

Abstract: A substantial body of evidence shows that several separate components underlie the late positive complex (LPC) of the ERP. Each of these has been proposed as a possible neural index of the orienting reflex (OR), but none has clearly met the criteria required for identification as an OR. The skin conductance response (SCR) is the most extensively examined index of the OR, and was used here as an OR 'yard-stick'. The primary aim of this study was to determine if any of the components of the LPC show stimulus-response relationships analogous to those of the SCR. ERPs and SCRs were simultaneously recorded from 72 subjects during an ERP dishabituation paradigm, in which a habituation stimulus (S1) was presented for a series of trials, during which a different stimulus (S2) was interpolated. This sequence was presented in a series of trains, allowing across-train LPC and SCR exploration as a function of trial. The sensitivity of these components to stimulus intensity and significance, other stimulus dimensions important in defining the OR, was also examined. We utilised a PCA with varimax rotation to separate the ERP components underlying the LPC. Four factors extracted appeared to correspond to the classic Slow Wave, the P3b, the Novelty P3 and the P3a. While the LPC exhibited a stimulus-response relationship analogous to the SCR, each of the separate components was differentially sensitive to aspects of the stimulus manipulations examined here. This study has demonstrated that the LPC is an adequate EEG index of the OR. However, the underlying components of the LPC examined here--which we consider to be the classic slow wave, P3b, Novelty P3 and P3a--cannot be used interchangeably as OR indices. This study clarifies links between the autonomic OR and its CNS correlates.

Ostracism and physiological arousal following traumatic brain injury

Publisher: Informa UK Limited

Date: 21-02-2017

DOI: 10.1080/02699052.2016.1271457

Abstract: This study aimed to examine the psychological and physiological effects of ostracism in adults with traumatic brain injury (TBI). A within-subject, counterbalanced design was used. The two conditions, inclusion and ostracism, were examined across two groups (between subjects). A group of 21 adults with TBI and 17 matched controls participated in the Cyberball paradigm. This task is a computerised task that exposes participants to a game of catch and throw. In the inclusion condition they are included fairly in the game, while in the ostracism condition they are excluded from the game following the first few throws. Skin conductance levels (SCLs) were measured throughout the game as a proxy for social stress. Results showed that people with TBI were cognitively aware of when they are being ostracised, but that their self-reported emotional experience to social exclusion was different to that of the control group. Differences in SCLs between groups and between conditions did not reach significance nor did they correlate with behavioural responses. These findings are discussed in terms of the consequences of dissociation between psychological and physiological responses and the implications for motivating behaviours associated with re-inclusion.

Goal‐directed EEG activity evoked by discriminative stimuli in reinforcement learning

Publisher: Wiley

Date: 06-08-2014

DOI: 10.1111/PSYP.12302

Abstract: In reinforcement learning (RL), discriminative stimuli (S) allow agents to anticipate the value of a future outcome, and the response that will produce that outcome. We examined this processing by recording EEG locked to S during RL. Incentive value of outcomes and predictive value of S were manipulated, allowing us to discriminate between outcome-related and response-related activity. S predicting the correct response differed from nonpredictive S in the P2. S paired with high-value outcomes differed from those paired with low-value outcomes in a frontocentral positivity and in the P3b. A slow negativity then distinguished between predictive and nonpredictive S. These results suggest that, first, attention prioritizes detection of informative S. Activation of mental representations of these informative S then retrieves representations of outcomes, which in turn retrieve representations of responses that previously produced those outcomes.

Impaired emotional contagion following severe traumatic brain injury

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.IJPSYCHO.2013.06.013

Abstract: Empathy deficits are widely-documented in in iduals after severe traumatic brain injury (TBI). This study examined the relationship between empathy deficits and psychophysiological responsivity in adults with TBI to determine if impaired responsivity is ameliorated through repeated emotional stimulus presentations. Nineteen TBI participants (13 males 41 years) and 25 control participants (14 males 31 years) viewed five repetitions of six 2-min film clip segments containing pleasant, unpleasant, and neutral content. Facial muscle responses (zygomaticus and corrugator), tonic heart rate (HR) and skin conductance level (SCL) were recorded. Mean responses for each viewing period were compared to a pre-experiment 2-min resting baseline period. Self-reported emotional empathy was also assessed. TBI participants demonstrated identical EMG response patterns to controls, i.e. an initial large facial response to both pleasant and unpleasant films, followed by habituation over repetitions for pleasant films, and sustained response to unpleasant films. Additionally, an increase in both arousal and HR deceleration to stimulus repetitions was found, which was larger for TBI participants. Compared to controls, TBI participants self-reported lower emotional empathy, and had lower resting arousal, and these measures were positively correlated. Results are consistent with TBI producing impairments in emotional empathy and responsivity. While some normalisation of physiological arousal appeared with repeated stimulus presentations, this came at the cost of greater attentional effort.

Adolescent Performance on The Awareness of Social Inference Test: TASIT

Publisher: Cambridge University Press (CUP)

Date: 30-04-2015

DOI: 10.1017/BRIMP.2015.7

Abstract: Primary objective: Social cognition underlies social skills and can be disrupted in numerous developmental and acquired brain disorders during childhood and adolescence. Despite this, there are few tools to assess social cognition clinically in this age group. This study examined adolescent performance on The Awareness of Social Inference Test (TASIT), a valid measure of social cognition in adults. Design: Cross-sectional design examining performance on Parts 1, 2 and 3 of TASIT (and alternate forms) in Australian girls and boys with varying levels of English familiarity. Methods: 665 schoolchildren from private and government schools were administered TASIT subtests. Of these, 464 students aged 13–15 were selected to provide normative data. Scores from a further 97 provided information about the effects of lack of English familiarity. Results: The two Forms of TASIT were statistically equivalent for two of the three parts. Adolescents performed lower than adults, although the differences were not large. Some incremental effects were seen for chronological age. Gender effects were apparent on all subtests. Lack of English familiarity (i.e., English not spoken at home) reduced scores a further 6–13% relative to high English proficiency. Conclusions: TASIT appears to be suitable for adolescents. Norms are best aggregated across ages in adolescence and stratified according to gender.

Event-related potential correlates of phasic and tonic measures of the orienting reflex

Publisher: Elsevier BV

Date: 07-2007

DOI: 10.1016/J.BIOPSYCHO.2007.03.003

Abstract: We examined putative central nervous system (CNS) indices of tonic and phasic aspects of the orienting reflex (OR) in a passive event-related potential (ERP) dishabituation paradigm. Pre-stimulus skin conductance level (SCL) and the subsequent skin conductance response (SCR) were used as tonic and phasic OR "yard-sticks", respectively. Their stimulus-response patterns were used to assess two ERP components: the tonic pre-stimulus contingent negative variation (CNV) and the subsequent phasic late positive complex (LPC). SCLs and SCRs derived from each trial of the first train presented were compatible with traditional OR studies. Across-train means were also derived for each of the four measures examined. Arousal changes, as indexed by the SCL, were weak in the CNV which showed an additional expectancy effect. The LPC showed a stimulus-response pattern across trials identical to that of the SCR. This study clarifies links between the traditional autonomic measures of the indifferent OR and its CNS correlates, and encourages an OR perspective and/or interpretation of ERP effects.

Autonomic and neural correlates of dysregulated arousal in severe traumatic brain injury

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.IJPSYCHO.2013.05.009

Abstract: Severe traumatic brain injury (TBI) in adults is associated with abnormalities in arousal and emotional responsivity, which are observed physiologically, behaviourally and via self-report measures. While an accurate measure of physiological arousal is debated, Barry et al. (2005, 2007, 2008) have consistently shown an inverse relationship between skin conductance level (SCL), and mean alpha power (alpha) during an eyes-closed resting condition (EC), accompanied by an increase in SCL and corresponding decrease in alpha during eyes-open (EO). Thus, alpha may provide a novel index of autonomic arousal. This study aimed to elucidate the neural and autonomic correlates of arousal disturbances in TBI. Participants were 17 adults with TBI (13 males mean age 46.50) and 22 matched controls (14 males mean age 41.25). Mean alpha and SCL were recorded across two 2 minute conditions (EC and EO). Paralleling previous research (e.g., Barry et al., 2007), a significant decrease in alpha was found from EC to EO for the s le overall, but this was significantly reduced in TBI participants. Further, TBI participants showed diminished regional differences compared to controls. Lower SCLs across EC-EO were also found in TBI participants compared to controls. Contrasting expectations, an increase in SCL from EC to EO was not found. This study showed that examining simple alpha changes provides insight into TBI-related arousal disturbances. Importantly, our findings accord with the nature of TBI, which involves global and region-specific damage.

Single-trial event-related potentials and the orienting reflex to monaural tones

Publisher: Elsevier BV

Date: 02-2011

DOI: 10.1016/J.IJPSYCHO.2010.09.010

Abstract: We aimed to clarify the event-related potentials (ERPs) involved in elicitation and habituation of the orienting reflex (OR), seeking parallels with two autonomic measures reflecting different stages in OR-related processing. Participants were presented with 8 unexpected innocuous novel tones to one ear at long variable inter-stimulus intervals, and horizontal eye movement in the direction of the ear of stimulation was taken as a behavioural measure of the OR. Skin conductance, heart rate, and 19 EEG channels were also recorded. Single-trial ERPs were decomposed using principal components analysis for intervals covering the early N1 complex and the late positive complex (LPC). Eye movements at trial 1 showed significant directional differences with ear of stimulation, and this difference reduced over trials, providing behavioural evidence of OR elicitation and habituation. Electrodermal responses, Processing Negativity, and the Novelty P3 showed substantial main effects of trials, suggesting their close links to the OR. Cardiac deceleration and Component 1 of the N1 complex showed no change over trials, suggesting their association in marking the transient onset of each stimulus. Component 3 of the N1 complex, P3a, P3b, and early and late Slow Waves showed only topographic changes over trials, and their dominant continuation over the stimulus sequence rules them out as OR markers. Theory development is required to clarify the non-OR role of the LPC. These results point to the usefulness of a sequential-processing approach to the OR in accommodating the range of subcomponents in the ERP. These data also illustrate the value of single-trial ERP analysis in simple paradigms with very long inter-stimulus intervals.

EEG differences in children as a function of resting-state arousal level

Publisher: Elsevier BV

Date: 02-2004

DOI: 10.1016/S1388-2457(03)00343-2

Abstract: This study aimed to explore the basis of a theoretical position which has major impact in the current literature on attention-deficit/hyperactivity disorder (AD/HD) - that the ratio of theta to beta power in the EEG (the theta/beta ratio) represents central nervous system (CNS) arousal. Resting state topographic EEG activity was investigated as a function of CNS arousal in normal right-handed boys. Arousal was defined in terms of electrodermal activity, which has a long history in Psychology as a measure of CNS arousal. Relative delta, theta, and beta power, and the theta/beta ratio, failed to differ significantly between age-matched groups which differed markedly in skin conductance level and non-specific electrodermal fluctuations. The high-arousal group showed significantly lower levels of relative alpha power, particularly in posterior and hemispheric regions, with higher alpha frequencies in these areas. These data fail to support the theoretical linkage between the theta/beta ratio and CNS arousal. Further work is needed to disentangle the different correlates of arousal and task-related activation, particularly in cognitive and attentional-processing terms. The outcomes of this study, in addition to clarifying the nature of EEG markers of CNS arousal, have important implications for our understanding of AD/HD, as they require re-evaluation of current models of the disorder.

Transcranial direct current stimulation influences probabilistic association learning in schizophrenia

Publisher: Elsevier BV

Date: 09-2011

DOI: 10.1016/J.SCHRES.2011.06.021

Abstract: Schizophrenia is associated with heterogeneity in symptoms, cognition and treatment response. Probabilistic association learning, involving a gradual learning of cue-outcome associations, activates a frontal-striatal network in healthy adults. Studies of probabilistic association learning in schizophrenia have shown frontal-striatal dysfunction although considerable heterogeneity in performance has also been reported. Anodal transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex has been shown to improve probabilistic association learning in healthy adults. The aim of the current study was to determine the extent to which anodal tDCS to the left dorsolateral prefrontal cortex would reverse probabilistic association learning deficits in schizophrenia. Prior to tDCS, 20 people with schizophrenia performed an initial baseline assessment without stimulation. Anodal tDCS was administered continuously for 20 min at an intensity of 2.0 mA to the left dorsolateral prefrontal cortex in a single-blind, counterbalanced, sham-controlled, cross-over design while participants performed 150 trials of a probabilistic association learning test. Although anodal tDCS failed to improve probabilistic association learning based on the whole s le performance, greater variance in the active relative to the sham conditions suggested a subset of people may respond to treatment. Further correlation, regression and cluster analyses revealed differential effects of baseline performance on active tDCS and sham treatment and that there was a subset of people with schizophrenia who displayed improvement with tDCS suggesting that anodal tDCS to the dorsolateral prefrontal cortex may facilitate access to existing prefrontal cortex neural reserves in people with schizophrenia who show adequate capacity to learn at baseline.

The effects of inhibitory control training on alcohol consumption, implicit alcohol-related cognitions and brain electrical activity

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.IJPSYCHO.2013.04.011

Abstract: This study aimed to replicate findings that alcohol consumption and positive implicit beer-related cognitions can be reduced using inhibitory control (IC) training, with the addition of an active training control. Frontal EEG asymmetry, an objective psychophysiological index of approach motivation, was used as a dependent measure to examine training outcomes. Participants were randomly assigned to one of two IC training conditions (Beer NoGo or Beer Go) or a Brief Alcohol Intervention (BAI) (i.e. the active training control). The IC training tasks consistently paired a stimulus that required a response with images of water (Beer NoGo) or images of beer (Beer Go). Alcohol consumption and implicit beer-related cognitions were measured at pre-training, post-training and at one week follow-up. Frontal EEG asymmetry was recorded during a passive image viewing task that presented neutral, healthy, and beer stimuli - at pre-training, post-training and follow-up. Participants in the Beer NoGo and BAI conditions consumed less beer in a taste test immediately after training than Beer Go participants, suggesting that IC training may be as effective as the already established BAI. The taste test findings were in line with the frontal EEG asymmetry data, which indicated that approach motivation for beer stimuli was altered in the expected directions. However, the positive correlation between post-training frontal EEG asymmetry data and taste test consumption was not significant. While there were no significant changes in implicit beer-related cognitions following training, a trending positive relationship between implicit beer-related cognitions at post-training and taste test consumption was reported. Further exploration addressing the limitations of the current study is required in order to clarify the implications of these findings.

All alone with sweaty palms - Physiological arousal and ostracism

Publisher: Elsevier BV

Date: 03-2012

DOI: 10.1016/J.IJPSYCHO.2011.11.008

Abstract: Social exclusion, or ostracism, is universally perceived as a negative emotional experience and often leads to poor social outcomes for in iduals and society. Although the experience of distress associated with being ostracized is innate, there has been very little investigation of the effects on the autonomic nervous system. This study provides objective evidence for the effects of ostracism on arousal (examined with skin conductance levels) while participants played an internet ball-tossing game (Cyberball). Forty-two healthy undergraduate students participated in both inclusion and ostracism conditions. When participants were included, there was a marked decrement in arousal over the course of the task, whereas there was no evidence of habituation when participants were ostracized. The implications of these results are discussed in terms of the potential of differential autonomic activity to predict the coping strategies that people engage in following ostracism.

Understanding deficits in empathy after traumatic brain injury: The role of affective responsivity

Publisher: Elsevier BV

Date: 05-2011

DOI: 10.1016/J.CORTEX.2010.02.004

Abstract: People with traumatic brain injury (TBI) often find social situations challenging because they can no longer respond to the emotional state of the people they are with. Many also lack emotional empathy in their social interactions. But are these problems related? The present study addressed this question by examining psychophysiological indices of emotional responding, including facial electromyography (EMG) and skin conductance during exposure to happy and angry facial expressions, in addition to self-rated emotional empathy in 21 adults with severe TBI and 22 control participants. In comparison to control participants, those in the TBI group displayed a reduction in the ability to empathize emotionally, and showed reduced physiological responding to the emotional expression of anger. By contrast, the control group spontaneously mimicked the emotional expressions they were exposed to, regardless of affective valence, and also demonstrated higher skin conductance responsivity to angry faces. The data further suggested that a loss of emotional empathy plays a role in the emotional response deficits to angry facial expressions following TBI. The results have implications for understanding the impaired social functioning and poor quality of interpersonal relationships commonly seen as a consequence of TBI.

Autonomic arousal explains social cognitive abilities in high-functioning adults with autism spectrum disorder

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.IJPSYCHO.2013.04.014

Abstract: Empirical research into behavioural profiles and autonomic responsivity in in iduals with autism spectrum disorders (ASDs) is highly variable and inconsistent. Two preliminary studies of children with ASDs suggest that there may be subgroups of ASDs depending on their resting arousal levels, and that these subgroups show different profiles of autonomic responsivity. The aim of the present study was to determine whether (i) adults with high-functioning ASDs may be separated into subgroups according to variation in resting arousal and (ii) these ASD arousal subgroups differ in their behavioural profiles for basic emotion recognition, judgements of trustworthiness, and cognitive and affective empathy. Thirty high-functioning adults with ASDs and 34 non-clinical controls participated. Resting arousal was determined as the average skin conductance (SCL) across a 2 min resting period. There was a subgroup of ASD adults with significantly lower resting SCL. These in iduals demonstrated poorer emotion recognition, tended to judge faces more negatively, and had atypical relationships between SCL and affective empathy. In contrast, low cognitive empathy was a feature of all ASD adults. These findings have important implications for clinical interventions and future studies investigating autonomic functioning in ASDs.

Neurophysiological correlates of dysregulated emotional arousal in severe traumatic brain injury

Publisher: Elsevier BV

Date: 02-2015

DOI: 10.1016/J.CLINPH.2014.05.033

Abstract: This study aimed to elucidate relationships between dysregulated emotional arousal after severe traumatic brain injury (TBI), alpha power and skin conductance levels (SCL), and brain atrophy. Nineteen adults with severe TBI and 19 age-, education-, and gender-matched controls (all p's>0.05) participated. Magnetic resonance imaging (MRI) scan established bilateral insulae and amygdale volumes. Mean EEG alpha power and SCLs were recorded simultaneously across four, 2 min conditions: eyes-closed pre-task baseline, view neutral face, happy face and angry face. Scalp-wide alpha suppression occurred from pre-task baseline to the face-viewing conditions (p<.001), but was diminished in TBI (p=.04). TBI participants exhibited marginally significantly lower SCL (p=.051), and elevated alpha power hemispherically, contrasting with controls' midline dominance (p<.01). Significant atrophy was observed in most structures in TBI participants (p's=.004-0.04). Larger left insula, left amygdala and right amygdala correlated positively with alpha power and alpha suppression, and SCLs all structures uniquely contributed to variance in arousal. Findings suggest that alpha power provides a sensitive measure of dysregulated emotional arousal post-TBI. Atrophy in pertinent brain structures may contribute to these disturbances. These findings have potential implications for the assessment and remediation of TBI-related arousal deficits, by directing more targeted remediation, and better assessing post-TBI recovery.

Reduced heart rate variability in chronic severe traumatic brain injury: Association with impaired emotional and social functioning, and potential for treatment using biofeedback

Publisher: Informa UK Limited

Date: 28-01-2016

DOI: 10.1080/09602011.2014.1003246

Abstract: Heart rate variability (HRV) may provide an index of capacity for social functioning and may be remediated by HRV biofeedback. Given reductions in HRV are found following traumatic brain injury (TBI), the present study aimed to determine whether lower HRV in TBI is associated with social function, and whether HRV biofeedback might be a useful remediation technique in this population. Resting state HRV and measures of social and emotional processing were collected in 30 in iduals with severe TBI (3-34 years post-injury) and 30 controls. This was followed by a single session of HRV biofeedback. HRV was positively associated with social cognition and empathy, and negatively associated with alexithymia for the TBI group. Both TBI and control groups showed significantly increased HRV on both time-domain (i.e., SDNN, rMSSD) and frequency-domain measures (LF, HF, LF:HF ratio) during biofeedback compared to baseline. These results suggest that decreased HRV is linked to social and emotional function following severe TBI, and may be a novel target for therapy using HRV biofeedback techniques.

Understanding how others feel: Evaluating the relationship between empathy and various aspects of emotion recognition following severe traumatic brain injury.

Publisher: American Psychological Association (APA)

Date: 03-2020

DOI: 10.1037/NEU0000609

Abstract: The aim of this study was to use various measures of emotion recognition, such as sensitivity to emotional intensity, accuracy-based emotion labeling, and the ability to differentiate among emotional displays, to examine whether these abilities are associated with emotional and cognitive empathy. We also sought to determine whether these relationships differ between in iduals with traumatic brain injury (TBI) and healthy adults. TBI participants ( Participants with TBI reported reduced emotional and cognitive empathy. TBI participants also had reduced overall accuracy in recognizing emotion, specifically for happy and sad emotions, although they had no difficulty identifying the intensity or differentiating among emotional displays. Intensity labeling and sensitivity to differentiate among emotions positively correlated with emotional empathy for healthy adults but not for TBI participants. No facet of emotion recognition correlated with cognitive empathy for healthy adults or TBI participants. The ability to identify the intensity and differentiate among emotions is associated with emotional empathy. Although in iduals with severe TBI may be able to differentiate emotions, they may be unable to utilize this information to share and understand the emotions of others, or vice versa. These results could have implications for understanding poor interpersonal relationships and impaired social functioning following TBI. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Single-trial event-related potentials and autonomic measures of the orienting reflex

Publisher: Elsevier BV

Date: 2012

DOI: 10.1016/J.IJPSYCHO.2011.10.007

Abstract: We aimed to clarify the event-related potentials (ERPs) associated with elicitation and habituation of the basic Orienting Reflex (OR). Participants were presented with 16 innocuous tones, alternating in intensity, at long variable inter-stimulus intervals, with no task. This allowed us to examine stimulus novelty and intensity effects in the absence of stimulus-related task demands. Single-trial ERPs were extracted to obtain estimates of the early N1 and the late positive complex (LPC) to each stimulus. Electrodermal responses showed substantial main effects of trials and intensity, supporting their functionality as an OR index. Cardiac deceleration showed no systematic change with intensity or trials, suggesting that it marks the transient onset of each stimulus, early in the stimulus-processing sequence. Respiratory pause showed a substantial main effect of trials but no intensity effect, suggesting that it reflects an intermediate processing stage. A main effect of intensity, but no simple trial effect, was apparent in the N1, suggesting that it reflects a different intermediate processing stage. The subsequent LPC showed only a topographic interaction with trials and intensity, failing to support any substantive role in OR processing. These different stimulus-response profiles are discussed in the context of a sequential processing model of the OR.

Social and Communication Disorders Following Traumatic Brain Injury

Publisher: Psychology Press

Date: 04-12-2013

DOI: 10.4324/9780203557198

An orienting reflex perspective on anteriorisation of the P3 of the event-related potential

Publisher: Springer Science and Business Media LLC

Date: 19-07-2006

DOI: 10.1007/S00221-006-0590-8

Abstract: In the Go/NoGo task, the P3 component of the event-related potential elicited by NoGo stimuli is topographically anterior to that from Go stimuli. This anteriorisation has been linked to the response inhibition thought to be required when NoGo stimuli are presented, and suggested as an index of inhibition. We report a preliminary investigation of this question from an orienting reflex (OR) perspective, in which the autonomic skin conductance response (SCR) was used as an OR "yardstick". We presented subjects with a random mix of 15 target and 15 non-target auditory stimuli with a short inter-stimulus interval, and explored the sources of the resultant P3s using low-resolution electromagnetic tomography (LORETA). Across-subject mean SCRs showed exponential decrement over trials and a larger response to targets, as expected from the OR perspective. LORETA analysis of the across-subject mean initial P3s showed exponential response decrement of their common sources, suggestive of the Novelty P3. Grand mean P3s to targets and non-targets appeared to correspond to the P3b and P3a, respectively. These results suggest that anteriorisation of the P3 to NoGo stimuli may reflect processing related to the basic involuntary OR to indifferent (non-significant) stimuli rather than an active inhibitory process.

Brain dynamics in the auditory oddball task as a function of stimulus intensity and task requirements

Publisher: Elsevier BV

Date: 09-2009

DOI: 10.1016/J.IJPSYCHO.2009.05.003

Abstract: We examined relationships between the phase of narrow-band electroencephalographic (EEG) activity at stimulus onset and the resultant event-related potentials (ERPs) in an auditory oddball task, varying both stimulus intensity and active vs. passive task requirements between groups. We used a novel conceptualisation of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). This study focused on the operation of three previously-reported phase-influenced mechanisms, involving prestimulus litudes, poststimulus litude changes, and the prestimulus contingent negative variation (CNV), in various EEG frequency bands. ERP responses to the standard stimuli were analysed. Prestimulus narrow-band EEG activity (in 1 Hz bands from 1 to 13 Hz) at Cz was assessed for each trial using digital filtering. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from both the filtered and unfiltered EEG activity at Fz, Cz, and Pz. The occurrence of preferred phase-defined brain states was confirmed at a number of frequencies, crossing the traditional frequency bands. These preferred states were associated with more efficient processing of the stimulus, as reflected in differences in latency and/or litude of all ERP components, and provided evidence of the operation of the three separate phase-influenced mechanisms. The preferred brain states occurred similarly across groups, suggesting that they reflect reflexive aspects of brain function associated with the timing of the stimuli, rather than voluntary attention. The impact on markers of cognitive function, such as the P3, suggests their important contributions to the efficiency of brain dynamics involved in perceptual and cognitive processing.

Brain dynamics in the active vs. passive auditory oddball task: Exploration of narrow-band EEG phase effects

Publisher: Elsevier BV

Date: 10-2007

DOI: 10.1016/J.CLINPH.2007.06.059

Abstract: We aimed to examine relationships between the phase of narrow-band electroencephalographic (EEG) activity at stimulus onset and the resultant event-related potentials (ERPs) in active vs. passive auditory oddball tasks, using a novel conceptualisation of orthogonal phase effects. This study focused on the operation of three recently-reported phase-influenced mechanisms, and ERP responses to the standard stimuli were analysed. Prestimulus narrow-band EEG activity (in 1 Hz bands from 1 to 13 Hz) at Cz was assessed for each trial using digital filtering. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from both the filtered and unfiltered EEG activity at Fz, Cz and Pz. Preferred brain states at various frequencies were indicated by approximately 20% differential occurrence within the orthogonal phase dimensions explored. The preferred states were associated with more efficient processing of the stimulus, as reflected in differences in latency and/or litude of various ERP components, and provided evidence for the operation of the three separate phase-influenced mechanisms. Both the occurrence of preferred brain states, and the mechanisms linking them to ERP outcomes focused on here, appeared relatively invariant across tasks, suggesting that they largely reflect reflexive brain processes.

EEG differences between eyes-closed and eyes-open resting conditions

Publisher: Elsevier BV

Date: 12-2007

DOI: 10.1016/J.CLINPH.2007.07.028

Abstract: Recent work has attempted to clarify the energetics of physiological responding and behaviour by refining and separating the operational definitions of "arousal" and "activation", which have different effects on physiological responding and behaviour. At the EEG level, we relate the former to widespread activity, and the latter to task-specific topographically-focussed activity reflecting regional processing. This study aimed to investigate this further in terms of differences in EEG activity between eyes-closed and eyes-open resting conditions. EEG activity was recorded from 28 university students during both eyes-closed and eyes-open resting conditions, Fourier transformed to provide estimates for absolute power in the delta, theta, alpha and beta bands, and analysed in 9 regions across the scalp. Skin conductance level was also measured as an indicator of arousal level. Across the eyes-closed conditions, skin conductance levels were negatively correlated with mean alpha levels. Skin conductance levels increased significantly from eyes-closed to eyes-open conditions. Reductions were found in across-scalp mean absolute delta, theta, alpha and beta from the eyes-closed to eyes-open condition. Topographic changes were also evident in all bands except for alpha, with reduced lateral frontal delta and posterior theta, and decreased posterior/increased frontal beta in the eyes-open condition. In particular, the topographic beta effects indicate that the across-scalp reduction arose from focal reductions rather than global changes. The obtained results confirm the use of mean alpha level as a measure of resting-state arousal under eyes-closed and eyes-open conditions. The focal nature of EEG effects in the other bands suggests that these reflect cortical processing of visual input, producing differences in activation between eyes-closed and eyes-open resting conditions, rather than just the simple increase in arousal level shown in alpha. This study demonstrates that the eyes-closed and eyes-open conditions provide EEG measures differing in topography as well as power levels. These differences should be recognised when evaluating EEG research, and considered when choosing eyes-open or eyes-closed baseline conditions for different paradigms.

Caffeine effects on ERPs and performance in an auditory Go/NoGo task

Publisher: Elsevier BV

Date: 12-2007

DOI: 10.1016/J.CLINPH.2007.08.023

Abstract: Previous research has shown that caffeine produces a general increase in arousal. The present study examined caffeine-induced arousal effects on performance and auditory ERPs. We sought components showing litude changes without topography changes, as would be expected of a pure arousal lification of source activity. The effects of a single oral dose of caffeine (250 mg) were examined in a randomised double-blind placebo-controlled repeated-measures cross-over study. Subjects abstained from caffeine for 4h before the testing sessions, which were conducted, in the afternoon, one week apart. A simple auditory Go/NoGo task was used, with a random mix of 75 tones at 1000 Hz and 75 at 1500 Hz. All tones were 60 dB SPL, 50 ms duration (rise/fall time 5 ms), with SOA 1100 ms. There was a reduction in RT, but no effects on omission or commission errors. The major ERP effects of caffeine were focal rather than global increases in P1, P2 and P3b litudes to Go stimuli, with no changes in latency. There were no effects on N1 or N2 to Go stimuli, and no effects on any components in response to NoGo stimuli. The results suggest that caffeine differentially improves aspects of the processing related to response production and task performance, contrary to the widespread lification of ERP component litudes, and latency reductions, expected of an increase in general arousal. These results add auditory ERP data to the list of complex effects of caffeine on brain function and behaviour. They appear to rule out a simple arousal interpretation, and suggest directions for future research.

Lack of Evidence for a Reduced Late Positive Potential in Major Depressive Disorder

Publisher: Cold Spring Harbor Laboratory

Date: 05-05-2020

DOI: 10.1101/2020.04.29.20085571

Abstract: In iduals with major depressive disorder (MDD) present with deficits in emotional reactivity. Conflicting models have been proposed to explain this effect. We sought to test the emotional context insensitivity hypothesis, which suggests that reactivity to positive and negatively-valenced emotional stimuli is blunted in depression, in a preregistered study. Forty-one depressed participants and 41 age- and gender-matched healthy controls were presented a series of unpleasant and neutrally-valenced pictures in a passive view paradigm while acquiring electroencephalography (EEG). The late positive potential (LPP), an EEG correlate of emotional reactivity, was compared between groups using mixed-effects repeated-measures models and exploratory cluster-based permutation tests. A sensitivity analysis was performed to assess the robustness of LPP findings by reanalysing the LPPs using 22 EEG pipelines from studies identified in the literature. We found no difference in LPP litudes between MDD and healthy in iduals using the preregistered analysis pipeline. The sensitivity analysis revealed that the magnitude and direction of LPP effect sizes were affected by the analysis pipeline. Exploratory permutation analyses revealed an electrode cluster that showed a significant reduction in the LPP for MDD participants while viewing unpleasant pictures. These results do not provide evidence in support of the emotional context insensitivity hypothesis, except for the exploratory data-driven approach. Methodological differences, in particular in the analysis pipeline, contribute to the heterogeneity of LPP modulation in depression. A standardised approach to quantify EEG correlates of emotional reactivity is needed to evaluate alternative models of emotional reactivity in depression.

Little evidence for a reduced late positive potential to unpleasant stimuli in major depressive disorder

Publisher: Elsevier BV

Date: 03-2022

DOI: 10.1016/J.YNIRP.2022.100077

Brain volume loss contributes to arousal and empathy dysregulation following severe traumatic brain injury

Publisher: Elsevier BV

Date: 02-2016

DOI: 10.1016/J.NICL.2016.09.017

The Physiological and Psychological Effects of Ostracism in Adults with ASD

Publisher: Springer Science and Business Media LLC

Date: 09-05-2017

DOI: 10.1007/S10803-017-3146-9

Abstract: Whilst some form of ostracism is experienced by most people at some point in their lives, it is experienced far more often in in iduals with Autism Spectrum Disorder (ASD). Little is known about how this social exclusion is interpreted, experienced or managed. This study aimed to explore the psychological (mood and social needs) as well as the physiological (arousal) effects of ostracism using a well-established paradigm, Cyberball. Results demonstrated no differences between groups on social needs, however, mood was rated as more negatively by ASDs overall. Arousal was increased in when excluded compared with when excluded for ASDs, but not for controls. Overall, in iduals with ASD experienced heightened physiological arousal but whilst these in iduals reported overall lower mood, this response to ostracism was not expressed as emotionally significant to these in iduals, suggesting possible interoceptive difficulties in this population. This highlights the need for both understanding in non-ASD in iduals and intervention of this emotional distress in in iduals with ASD.

The role of abnormalities in the corpus callosum in social cognition deficits after Traumatic Brain Injury

Publisher: Informa UK Limited

Date: 26-07-2018

DOI: 10.1080/17470919.2017.1356370

Abstract: The corpus callosum (CC) is vulnerable to severe traumatic brain injury (TBI). Social cognition requires integration of non-verbal and verbal information in order to understand social behaviour and may be compromised if the CC is damaged. 17 adults with severe, chronic TBI and 17 control participants underwent structural MRI and Diffusion Tensor Imaging. A region of interest analysis examined fractional anisotropy (FA) and mean diffusivity (MD) across regions of the CC. Performance on The Awareness of Social Inference Test (TASIT): part 1 (emotion recognition) and parts 2 and 3 (social inference), was examined in relation to FA and MD. Across participants, higher genu FA values were related to higher TASIT part 3 scores. Increased splenium FA was associated with better performance for TASIT parts 1-3. There was no association between DTI values and TASIT in the controls alone. In the TBI group, FA of the genu and splenium was correlated with TASIT part 3. The pattern of performance was similar when controlling for non-social cognitive ability. In conclusion, social information is complex and multi-modal requiring inter-hemispheric connection. People with TBI, regardless of focal grey matter injury, may lose social cognitive ability due to trauma related changes to the corpus callosum.

Event-related potentials in the auditory oddball as a function of EEG alpha phase at stimulus onset

Publisher: Elsevier BV

Date: 11-2004

DOI: 10.1016/J.CLINPH.2004.06.004

Abstract: We aimed to examine the relation between the phase of electroencephalogram (EEG) alpha activity at stimulus onset and event-related potentials (ERPs) in a fixed-inter-stimulus interval auditory 'oddball' task, using a novel conceptualisation of orthogonal phase effects (cortical negativity versus positivity, negative driving versus positive driving, waxing versus waning). EEG responses to button-press targets, from 14 subjects presented with 4 blocks of 150 stimuli (50% target probability), were examined. Pre-stimulus alpha activity (8-13 Hz) at Pz was assessed for each trial by digital filtering of the EEG. The alpha cycle at Pz, starting from a negative-going zero crossing, was used to sort trials into 4 phases, for which ERPs were derived from both the filtered and unfiltered EEG activity at Fz, Cz, and Pz. Preferred brain states in this paradigm were indicated by an 8% greater occurrence of negative driving than positive driving, and a 33% greater occurrence of waxing than waning phases. Negative driving phases were associated with increased N1 latencies and decreased N2 litudes. Latencies of N1 and P2 were reduced in waxing phases. These reflected systematic changes in alpha frequency and litude at stimulus onset. In a fixed-inter-stimulus interval paradigm, component frequencies of the EEG are dynamically adjusted in order to provide brain states at the moment of stimulus presentation which differentially affect the EEG correlates of stimulus processing. The results add to our understanding of the genesis of the ERP, indicating the importance of the dynamic interplay between instantaneous EEG activity and stimulus processing reflected in the ERP.

Age and gender effects in EEG coherence: I. Developmental trends in normal children

Publisher: Elsevier BV

Date: 10-2004

DOI: 10.1016/J.CLINPH.2004.05.004

Frontal and parietal contributions to probabilistic association learning

Publisher: Oxford University Press (OUP)

Date: 07-01-2011

DOI: 10.1093/CERCOR/BHQ255

Single-trial event-related potentials to significant stimuli

Publisher: Elsevier BV

Date: 11-2009

DOI: 10.1016/J.IJPSYCHO.2009.08.003

Abstract: The stimulus-response pattern of the skin conductance response (SCR) was used as a model of the Orienting Reflex (OR) to assess the P1, N1, P2, N2 and late positive complex (LPC/P300) components of the ERP in a simple habituation paradigm, in which a single series of 12 innocuous tones were presented at a very long interstimulus interval (2 min). To maintain their waking state during this boring task, participants were instructed to alternately close or open their eyes to each stimulus. None of the baseline-to-peak ERP measures showed trials effects comparable with the marked habituation over trials shown by the SCRs. Principal Components Analysis was used to decompose the ERP, yielding factors identified as the N1, N2, P3a, P3b and Novelty P3 components. An additional factor represented later eye-movement activity. No trial effects were apparent for the N1, N2, P3a or P3b components. The Novelty P3 showed marked response decrement over trials. These results are discussed in relation to current conceptualisations of the OR.

The influence of attention and arousal on emotion perception in adults with severe traumatic brain injury

Publisher: Elsevier BV

Date: 10-2011

DOI: 10.1016/J.IJPSYCHO.2011.01.014

Abstract: Many people with traumatic brain injury (TBI) have poor emotion recognition, with negative emotions more frequently impaired. They can also display abnormal affective responses to emotionally charged material, however, the mechanisms underpinning such deficits are unclear. This study examined whether affective responsivity can be improved by focusing attention and whether responsivity is associated with perception accuracy. Eighteen adults with moderate-to-severe TBI and 18 control participants viewed facial expressions while skin conductance (SCR) and evoked cardiac deceleration (ECD) (used as indices of orientation) and skin conductance levels (SCL) (used as an index of phasic arousal) were monitored. They viewed two blocks of faces (8 angry and 8 happy per block), passively in the first block and with the instruction to identify the emotional expression in the second. No differences between conditions, emotions or groups were found using SCR. Both groups demonstrated increasing ECD for the attend condition relative to the passive condition. For the passive task the control group showed increasing SCL (sensitisation) over trials when viewing angry faces and decreasing SCL (habituation) to happy faces. No differences between emotions were shown for the TBI group who rapidly habituated to both expressions. For the attend task, there was no evidence of habituation for either expression for either the control or TBI participants. Physiological measures did not correlate to accuracy in recognising emotions. The results suggest that increasing attentional demands improves orientation and emotional engagement (arousal) to emotional faces following TBI. However, the relationship to this and emotion perception accuracy remains unclear.

Timing of caffeine's impact on autonomic and central nervous system measures: Clarification of arousal effects

Publisher: Elsevier BV

Date: 03-2008

DOI: 10.1016/J.BIOPSYCHO.2007.11.002

Abstract: The timing of caffeine effects on arousal levels was examined. From previous work in our laboratory, an increase in skin conductance level (SCL) was used as the marker of arousal increase, and we sought to identify the timing of this and related effects following caffeine ingestion. A single oral dose of caffeine (250 mg) was used in a randomised double-blind placebo-controlled repeated-measures cross-over study. Eyes-closed resting electroencephalogram (EEG) and autonomic data (SCL, heart rate, respiration rate, and systolic and diastolic blood pressure) during 2 min epochs that commenced every 4 min after ingestion, were analysed. The SCL placebo data were used to identify potential arousal measures prior to examining caffeine effects. Caffeine was associated with increased SCL, increased respiratory rate and a global reduction in alpha power. There were no significant cardiovascular effects of caffeine-induced arousal. These caffeine results are consistent with our recent electrodermal and EEG studies of arousal, and confirm the potential use of caffeine as a simple means of experimentally modifying arousal levels without task-related confounds.

Emotion in voice matters: Neural correlates of emotional prosody perception

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.IJPSYCHO.2013.06.025

Abstract: The ability to perceive emotions is imperative for successful interpersonal functioning. The present study examined the neural characteristics of emotional prosody perception with an exploratory event-related potential analysis. Participants were 59 healthy in iduals who completed a discrimination task presenting 120 semantically neutral word pairs from five prosody conditions (happy/happy, angry/angry, neutral/neutral, angry/happy, happy/angry). The task required participants to determine whether words in the pair were spoken in same or different emotional prosody. Reflective of an initial processing stage, the word 1 N1 component was found to have greatest litude in parietal regions of the hemispheres, and was largest for emotional compared to neutral stimuli, indicating detection of emotion features. A second processing stage, represented by word 1 P2, showed similar topographic effects however, litude was largest for happy in the left hemisphere while angry was largest in the right, illustrating differentiation of emotions. At the third processing stage, word 1 N3 litude was largest in frontal regions, indicating later cognitive processing occurs in the frontal cortex. N3 was largest for happy, which had lowest accuracy compared to angry and neutral. The present results support Schirmer and Kotz's (2006) model of vocal emotion perception because they elucidated the function and ERP components by reflecting three primary stages of emotional prosody perception, controlling for semantic influence.

Erratum to Single-trial event-related potentials and the orienting reflex to monaural tones. [International Journal of Psychophysiology, 79, 2, 127-136].

Publisher: Elsevier BV

Date: 05-2011

DOI: 10.1016/J.IJPSYCHO.2011.03.002

Understanding advanced theory of mind and empathy in high-functioning adults with autism spectrum disorder

Publisher: Informa UK Limited

Date: 07-2013

DOI: 10.1080/13803395.2013.809700

Abstract: It has been argued that higher functioning in iduals with autism spectrum disorders (ASDs) have specific deficits in advanced but not simple theory of mind (ToM), yet the questionable ecological validity of some tasks reduces the strength of this assumption. The present study employed The Awareness of Social Inference Test (TASIT), which uses video vignettes to assess comprehension of subtle conversational inferences (sarcasm, lies/deception). Given the proposed relationships between advanced ToM and cognitive and affective empathy, these associations were also investigated. As expected, the high-functioning adults with ASDs demonstrated specific deficits in comprehending the beliefs, intentions, and meaning of nonliteral expressions. They also had significantly lower cognitive and affective empathy. Cognitive empathy was related to ToM and group membership whereas affective empathy was only related to group membership.

Automatic facial responses to affective stimuli in high-functioning adults with autism spectrum disorder

Publisher: Elsevier BV

Date: 2013

DOI: 10.1016/J.PHYSBEH.2012.10.008

Abstract: In iduals with autism spectrum disorder (ASD) demonstrate atypical behavioural responses to affective stimuli, although the underlying mechanisms remain unclear. Investigating automatic responses to these stimuli may help elucidate these mechanisms. 18 high-functioning adults with ASDs and 18 typically developing controls viewed 54 extreme pleasant (erotica), extreme unpleasant (mutilations), and non-social neutral images from the International Affective Picture System (IAPS). Two-thirds of images received an acoustic startle probe 3s post-picture onset. Facial electromyography (EMG) activity (orbicularis, zygomaticus, corrugator), skin conductance (SCR) and cardiac responses were recorded. The adults with ASDs demonstrated typical affective startle modulation and automatic facial EMG responses but atypical autonomic (SCRs and cardiac) responses, suggesting a failure to orient to, or a deliberate effort to disconnect from, socially relevant stimuli (erotica, mutilations). These results have implications for neural systems known to underlie affective processes, including the orbitofrontal cortex and amygdala.

Psychophysiological correlates of social judgement in high-functioning adults with autism spectrum disorder

Publisher: Elsevier BV

Date: 2013

DOI: 10.1016/J.IJPSYCHO.2012.11.005

Abstract: Neural structures involved in social cognition (e.g., amygdala, orbitofrontal cortex) have been implicated in judgements of trustworthiness. These regions are also functionally atypical in in iduals with autism spectrum disorders (ASDs). Studies investigating judgements of trustworthiness in ASDs have suggested possible disruptions in the allocation of significance to social stimuli. Concurrent measures of autonomic responses provide further insight into these deficits, given their role in the direction of attention and allocation of significance. Thirty high-functioning adults with ASDs and 31 non-clinical controls viewed neutral images piloted as most "positive" and "negative." Skin conductance (SCR, SCL) and evoked cardiac deceleration (ECD) were recorded. Adults with ASDs did not differ from controls in ratings of trustworthiness. However, they displayed atypical SCRs, providing further support for a disruption in the allocation of emotional significance.

University Of New South Wales

Location: Australia

View Organisation

University Of Wollongong

Location: Australia

View Organisation

Discovery Projects - Grant ID: DP1094183

Start Date: 03-2010

End Date: 12-2014

Amount: $244,212.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP150100226

Start Date: 03-2015

End Date: 12-2019

Amount: $397,900.00

Funder: Australian Research Council