ORCID Profile
0000-0002-3980-5864
Current Organisations
University of Western Australia
,
Curtin 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)
Psychology | Biological Psychology (Neuropsychology, Psychopharmacology, Physiological Psychology) | Sensory Processes, Perception and Performance | Sensory Processes, Perception And Performance | Developmental Psychology And Ageing | Developmental Psychology and Ageing
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Psychology and Cognitive Sciences | Behavioural and cognitive sciences |
Related Links
Publications
Facial expression coding in children and adolescents with autism: Reduced adaptability but intact norm-based coding
Publisher: Wiley
Date: 19-07-2018
DOI: 10.1111/BJOP.12257
Abstract: In iduals with autism spectrum disorder (ASD) can have difficulty recognizing emotional expressions. Here, we asked whether the underlying perceptual coding of expression is disrupted. Typical in iduals code expression relative to a perceptual (average) norm that is continuously updated by experience. This adaptability of face-coding mechanisms has been linked to performance on various face tasks. We used an adaptation aftereffect paradigm to characterize expression coding in children and adolescents with autism. We asked whether face expression coding is less adaptable in autism and whether there is any fundamental disruption of norm-based coding. If expression coding is norm-based, then the face aftereffects should increase with adaptor expression strength (distance from the average expression). We observed this pattern in both autistic and typically developing participants, suggesting that norm-based coding is fundamentally intact in autism. Critically, however, expression aftereffects were reduced in the autism group, indicating that expression-coding mechanisms are less readily tuned by experience. Reduced adaptability has also been reported for coding of face identity and gaze direction. Thus, there appears to be a pervasive lack of adaptability in face-coding mechanisms in autism, which could contribute to face processing and broader social difficulties in the disorder.
Race-specific norms for coding face identity and a functional role for norms
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 09-11-2011
DOI: 10.1167/11.13.9
Abstract: Models of face perception often adopt a framework in which faces are represented as points or vectors in a multidimensional space, relative to the average face that serves as a norm for encoding. Since faces are very similar in their configuration and share many visual properties, they could be encoded in one common space against one norm. However, certain face properties may result in grouping and "subclassification" of similar faces. We studied the processing of faces of different races, using high-level aftereffects, where exposure to one face systematically distorts the perception of a subsequently viewed face toward the "opposite" identity in face space. We measured identity aftereffects for adapt-test pairs that were opposite relative to race-specific (Asian and Caucasian) averages and pairs that were opposite relative to a "generic" average (both races morphed together). Aftereffects were larger for race-specific compared to mixed-race adapt-test pairs. These results suggest that race-specific norms are used to code identity because aftereffects are generally larger for adapt-test pairs drawn from trajectories passing through the norm (opposite pairs) than for those that do not. We also found that identification thresholds were lower when targets were distributed around race-specific averages than around the mixed-race average, suggesting that norm-based face encoding may play a functional role in facilitating identity discrimination.
How distinct is the coding of face identity and expression? Evidence for some common dimensions in face space
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.COGNITION.2015.05.012
Abstract: Traditional models of face perception emphasize distinct routes for processing face identity and expression. These models have been highly influential in guiding neural and behavioural research on the mechanisms of face perception. However, it is becoming clear that specialised brain areas for coding identity and expression may respond to both attributes and that identity and expression perception can interact. Here we use perceptual aftereffects to demonstrate the existence of dimensions in perceptual face space that code both identity and expression, further challenging the traditional view. Specifically, we find a significant positive association between face identity aftereffects and expression aftereffects, which dissociates from other face (gaze) and non-face (tilt) aftereffects. Importantly, in idual variation in the adaptive calibration of these common dimensions significantly predicts ability to recognize both identity and expression. These results highlight the role of common dimensions in our ability to recognize identity and expression, and show why the high-level visual processing of these attributes is not entirely distinct.
Autistic traits are linked to reduced adaptive coding of face identity and selectively poorer face recognition in men but not women
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2013.08.016
Abstract: Our ability to discriminate and recognize thousands of faces despite their similarity as visual patterns relies on adaptive, norm-based, coding mechanisms that are continuously updated by experience. Reduced adaptive coding of face identity has been proposed as a neurocognitive endophenotype for autism, because it is found in autism and in relatives of in iduals with autism. Autistic traits can also extend continuously into the general population, raising the possibility that reduced adaptive coding of face identity may be more generally associated with autistic traits. In the present study, we investigated whether adaptive coding of face identity decreases as autistic traits increase in an undergraduate population. Adaptive coding was measured using face identity aftereffects, and autistic traits were measured using the Autism-Spectrum Quotient (AQ) and its subscales. We also measured face and car recognition ability to determine whether autistic traits are selectively related to face recognition difficulties. We found that men who scored higher on levels of autistic traits related to social interaction had reduced adaptive coding of face identity. This result is consistent with the idea that atypical adaptive face-coding mechanisms are an endophenotype for autism. Autistic traits were also linked with face-selective recognition difficulties in men. However, there were some unexpected sex differences. In women, autistic traits were linked positively, rather than negatively, with adaptive coding of identity, and were unrelated to face-selective recognition difficulties. These sex differences indicate that autistic traits can have different neurocognitive correlates in men and women and raise the intriguing possibility that endophenotypes of autism can differ in males and females.
Adaptation modulates the electrophysiological substrates of perceived facial distortion: Support for opponent coding
Publisher: Elsevier BV
Date: 11-2010
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2010.08.016
Abstract: In two experiments we determined the electrophysiological substrates of figural aftereffects in face adaptation using compressed and expanded faces. In Experiment 1, subjects viewed a series of compressed and expanded faces. Results demonstrated that distortion systematically modulated the peak litude of the P250 event-related potential (ERP) component. As the amount of perceived distortion in a face increased, the peak litude of the P250 component decreased, regardless of whether the physical distortion was compressive or expansive. This provided an ERP metric of the degree of perceived distortion. In Experiment 2, we examined the effects of adaptation on the P250 litude by introducing an adapting stimulus that affected the subject's perception of the distorted test faces as measured through normality judgments. The set of test faces was held constant and the adapting stimulus was systematically varied across experimental days. Adapting to a compressed face made a less compressed test face appear more normal and an expanded test face more distorted as measured by normality ratings. We found that the adaptation conditions that increased the perceived distortion of the distorted test faces also decreased the litude of the P250. Likewise, adaptation conditions that decreased the perceived distortion of the distorted test faces also increased the litude of the P250. The results demonstrate that perceptual adaptation to compressed or expanded faces affected not only the behavioral normality judgments but also the electrophysiological correlates of face processing in the window of 190-260 ms after stimulus onset.
Assessing early processing of eye gaze in schizophrenia: measuring the cone of direct gaze and reflexive orienting of attention
Publisher: Informa UK Limited
Date: 14-02-2017
DOI: 10.1080/13546805.2017.1285755
Abstract: The accurate discrimination of another person's eye-gaze direction is vital as it provides a cue to the gazer's focus of attention, which in turn supports joint attention. Patients with schizophrenia have shown a "direct gaze bias" when judging gaze direction. However, current tasks do not dissociate an early perceptual bias from high-level top-down effects. We investigated early stages of gaze processing in schizophrenia by measuring perceptual sensitivity to fine deviations in gaze direction (i.e., the cone of direct gaze: CoDG) and ability to reflexively orient to locations cued by the same deviations. Twenty-four patients and 26 controls completed a CoDG discrimination task that used realistic direct-face images with six fine degrees of deviation (i.e., 3, 6 or 9 pixels to the left and right) and direct gaze, and a gaze cueing task that assessed reflexive orienting to the same fine-grained deviations. Our data showed patients exhibited no impairment in gaze discrimination, nor did we observe a reduced orienting response. These results suggest that while patients may suffer deficits associated with interpreting another person's gaze, the earliest processes concerned with detecting averted gaze and reflexively orienting to the gazed-at location are intact.
Nine-Year-Old Children Use Norm-Based Coding to Visually Represent Facial Expression
Publisher: American Psychological Association (APA)
Date: 2013
DOI: 10.1037/A0031117
Abstract: Children are less skilled than adults at making judgments about facial expression. This could be because they have not yet developed adult-like mechanisms for visually representing faces. Adults are thought to represent faces in a multidimensional face-space, and have been shown to code the expression of a face relative to the norm or average face in face-space. Norm-based coding is economical and adaptive, and may be what makes adults more sensitive to facial expression than children. This study investigated the coding system that children use to represent facial expression. An adaptation aftereffect paradigm was used to test 24 adults and 18 children (9 years 2 months to 9 years 11 months old). Participants adapted to weak and strong antiexpressions. They then judged the expression of an average expression. Adaptation created aftereffects that made the test face look like the expression opposite that of the adaptor. Consistent with the predictions of norm-based but not exemplar-based coding, aftereffects were larger for strong than weak adaptors for both age groups. Results indicate that, like adults, children's coding of facial expressions is norm-based.
Enhanced attention amplifies face adaptation
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.VISRES.2011.06.008
Abstract: Perceptual adaptation not only produces striking perceptual aftereffects, but also enhances coding efficiency and discrimination by calibrating coding mechanisms to prevailing inputs. Attention to simple stimuli increases adaptation, potentially enhancing its functional benefits. Here we show that attention also increases adaptation to faces. In Experiment 1, face identity aftereffects increased when attention to adapting faces was increased using a change detection task. In Experiment 2, figural (distortion) face aftereffects increased when attention was increased using a snap game (detecting immediate repeats) during adaptation. Both were large effects. Contributions of low-level adaptation were reduced using free viewing (both experiments) and a size change between adapt and test faces (Experiment 2). We suggest that attention may enhance adaptation throughout the entire cortical visual pathway, with functional benefits well beyond the immediate advantages of selective processing of potentially important stimuli. These results highlight the potential to facilitate adaptive updating of face-coding mechanisms by strategic deployment of attentional resources.
The dynamics of visual adaptation to faces
Publisher: The Royal Society
Date: 05-05-2005
Abstract: Several recent demonstrations using visual adaptation have revealed high-level aftereffects for complex patterns including faces. While traditional aftereffects involve perceptual distortion of simple attributes such as orientation or colour that are processed early in the visual cortical hierarchy, face adaptation affects perceived identity and expression, which are thought to be products of higher-order processing. And, unlike most simple aftereffects, those involving faces are robust to changes in scale, position and orientation between the adapting and test stimuli. These differences raise the question of how closely related face aftereffects are to traditional ones. Little is known about the build-up and decay of the face aftereffect, and the similarity of these dynamic processes to traditional aftereffects might provide insight into this relationship. We examined the effect of varying the duration of both the adapting and test stimuli on the magnitude of perceived distortions in face identity. We found that, just as with traditional aftereffects, the identity aftereffect grew logarithmically stronger as a function of adaptation time and exponentially weaker as a function of test duration. Even the subtle aspects of these dynamics, such as the power-law relationship between the adapting and test durations, closely resembled that of other aftereffects. These results were obtained with two different sets of face stimuli that differed greatly in their low-level properties. We postulate that the mechanisms governing these shared dynamics may be dissociable from the responses of feature-selective neurons in the early visual cortex.
Adaptation to dynamic faces produces face identity aftereffects
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 20-12-2018
DOI: 10.1167/18.13.13
Abstract: Face aftereffects are well established for static stimuli and have been used extensively as a tool for understanding the neural mechanisms underlying face recognition. It has also been argued that adaptive coding, as demonstrated by face aftereffects, plays a functional role in face recognition by calibrating our face norms to reflect current experience. If aftereffects tap high-level perceptual mechanisms that are critically involved in everyday face recognition then they should also occur for moving faces. Here we asked whether face identity aftereffects can be induced using dynamic adaptors. The face identity aftereffect occurs when adaptation to a particular identity (e.g., Dan) biases subsequent perception toward the opposite identity (e.g., antiDan). We adapted participants to video of real faces that displayed either rigid, non-rigid, or no motion and tested for aftereffects in static antifaces. Adapt and test stimuli differed in size, to minimize low-level adaptation. Aftereffects were found in all conditions, suggesting that face identity aftereffects tap high-level mechanisms important for face recognition. Aftereffects were not significantly reduced in the motion conditions relative to the static condition. Overall, our results support the view that face aftereffects reflect adaptation of high-level mechanisms important for real-world face recognition in which faces are moving.
The timecourse of expression aftereffects
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 12-2016
DOI: 10.1167/16.15.1
Abstract: Adaptation to facial expressions produces aftereffects that bias perception of subsequent expressions away from the adaptor. Studying the temporal dynamics of an aftereffect can help us to understand the neural processes that underlie perception, and how they change with experience. Little is known about the temporal dynamics of the expression aftereffect. We conducted two experiments to measure the timecourse of this aftereffect. In Experiment 1 we examined how the size of the aftereffect varies with changes in the duration of the adaptor and test stimuli. We found that the expression aftereffect follows the classic timecourse pattern of logarithmic build-up and exponential decay that has been demonstrated for many lower level aftereffects, as well as for facial identity and figural face aftereffects. This classic timecourse pattern suggests that the adaptive calibration mechanisms of facial expression are similar to those of lower level visual stimuli, and is consistent with a perceptual locus for the adaptation aftereffect. We also found that aftereffects could be generated by as little as 1 s of adaptation, and in some conditions lasted for as long as 3200 ms. We extended this last finding in Experiment 2, exploring the longevity of the expression aftereffect by adding a stimulus-free gap of varying duration between adaptation and test. We found that significant expression aftereffects were still present 32 s after adaptation. The persistence of the expression aftereffect suggests that they may have a considerable impact on day-to-day expression perception.
The timecourse of higher-level face aftereffects
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.VISRES.2007.05.012
Abstract: Perceptual aftereffects for simple visual attributes processed early in the cortical hierarchy increase logarithmically with adapting duration and decay exponentially with test duration. This classic timecourse has been reported recently for a face identity aftereffect [Leopold, D. A., Rhodes, G., Müller, K.-M., & Jeffery, L. (2005). The dynamics of visual adaptation to faces. Proceedings of the Royal Society of London, Series B, 272, 897-904], suggesting that the dynamics of visual adaptation may be similar throughout the visual system. An alternative interpretation, however, is that the classic timecourse is a flow-on effect of adaptation of a low-level, retinotopic component of the face identity aftereffect. Here, we examined the timecourse of the higher-level (size-invariant) components of two face aftereffects, the face identity aftereffect and the figural face aftereffect. Both showed the classic pattern of logarithmic build-up and exponential decay. These results indicate that the classic timecourse of face aftereffects is not a flow-on effect of low-level retinotopic adaptation, and support the hypothesis that dynamics of visual adaptation are similar at higher and lower levels of the cortical visual hierarchy. They also reinforce the perceptual nature of face aftereffects, ruling out demand characteristics and other post-perceptual factors as plausible accounts.
Development of face-based trustworthiness impressions in childhood
Publisher: Elsevier BV
Date: 2022
Adaptive norm-based coding of facial identity
Publisher: Elsevier BV
Date: 09-2006
DOI: 10.1016/J.VISRES.2006.03.002
Abstract: Identification of a face is facilitated by adapting to its computationally opposite identity, suggesting that the average face functions as a norm for coding identity [Leopold, D. A., O'Toole, A. J., Vetter, T., & Blanz, V. (2001). Prototype-referenced shape encoding revealed by high-level aftereffects. Nature Neuroscience, 4, 89-94 Leopold, D. A., Rhodes, G., Müller, K. -M., & Jeffery, L. (2005). The dynamics of visual adaptation to faces. Proceedings of the Royal Society of London, Series B, 272, 897-904]. Crucially, this interpretation requires that the aftereffect is selective for the opposite identity, but this has not been convincingly demonstrated. We demonstrate such selectivity, observing a larger aftereffect for opposite than non-opposite adapt-test pairs that are matched on perceptual contrast (dissimilarity). Component identities were also harder to detect in morphs of opposite than non-opposite face pairs. We propose an adaptive norm-based coding model of face identity.
Reduced face aftereffects in autism are not due to poor attention
Publisher: Public Library of Science (PLoS)
Date: 29-11-2013
Expression Recognition Difficulty Is Associated with Social But Not Attention-to-Detail Autistic Traits and Reflects Both Alexithymia and Perceptual Difficulty
Publisher: Springer Science and Business Media LLC
Date: 14-08-2019
DOI: 10.1007/S10803-019-04158-Y
Abstract: Autistic people often show difficulty with facial expression recognition. However, the degree of difficulty varies widely, which might reflect varying symptom profiles. We examined three domains of autistic traits in the typical population and found that more autistic-like social skills were associated with greater difficulty labelling expressions, and more autistic-like communication was associated with greater difficulty labelling and perceptually discriminating between expressions. There were no associations with autistic-like attention to detail. We also found that labelling, but not perceptual, difficulty was mediated by alexithymia. We found no evidence that labelling or perceptual difficulty was mediated by weakened adaptive coding. Results suggest expression recognition varies between the sub-clinical expressions of autistic symptom domains and reflects both co-occurring alexithymia and perceptual difficulty.
View-Specific Coding of Face Shape
Publisher: SAGE Publications
Date: 06-2006
DOI: 10.1111/J.1467-9280.2006.01735.X
Abstract: Monkey and human cortex contain view-specific face neurons, but it remains unclear whether they code face shape. We tested the view specificity of face-shape coding by inducing figural face aftereffects at one viewpoint (3/4 left) and testing generalization to different viewpoints (front view and 3/4 right). The aftereffects were induced by adaptation to consistent figural distortions (contracted or expanded), which shifts the distortion perceived as most normal toward the adapting distortion. The strong aftereffect that was observed at the adapting view was significantly and substantially reduced for both front-view test faces and mirror-image (3/4 right) test faces, indicating view specificity. The limited transfer across mirror views is strong evidence of view specificity, given their figural similarity. The aftereffects survived a size change between adaptation and test faces (Experiment 2), a result that rules out low-level adaptation as an explanation. These results provide strong evidence that face-shape coding is view-specific.
Face identity aftereffects increase monotonically with adaptor extremity over, but not beyond, the range of natural faces (vol 98, pg 1, 2014)
Publisher: Elsevier BV
Date: 03-2015
Transfer of figural face aftereffects suggests mature orientation selectivity in 8-year-olds' face coding
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.JECP.2014.03.003
Abstract: Adult face perception mechanisms are tuned to upright faces, and this orientation selectivity is central to adult expertise with upright faces. Children are less expert than adults, and it has been argued that their face mechanisms are less orientation selective than those of adults. Here we used face aftereffects to test this hypothesis by examining whether children's aftereffects show greater transfer across changes in orientation than do adults' aftereffects. We adapted 7- to 8-year-old children and adults to figural face distortions in both upright and inverted orientations and examined the size of resulting aftereffects in both upright and inverted test faces. If children's face mechanisms are less orientation selective than those of adults, then children's aftereffects should transfer more strongly across changes in orientation. We found no evidence to support this prediction. Children's and adults' aftereffects were similarly reduced by orientation differences between adapt and test. These results indicate that children, like adults, show a high degree of orientation selectivity in face shape coding and suggest that neural tuning to face orientation may be mature by 8 years of age. Our findings are consistent with an emerging view that many of the key attributes of specialized face perception emerge much earlier in development than previously thought.
Distinguishing Norm-Based From Exemplar-Based Coding of Identity in Children: Evidence From Face Identity Aftereffects
Publisher: American Psychological Association (APA)
Date: 2011
DOI: 10.1037/A0025643
Abstract: Children's performance on face identification tests improves dramatically between age 4 and adolescence, yet the source of this improvement is controversial. We used face identity aftereffects to examine whether changes in the organization of face-space during childhood could be a source of this improvement. Specifically we tested whether 7- to 9-year-old children, like adults, show patterns of aftereffects predicted by coding facial identity relative to a norm or the patterns predicted by exemplar-based coding. Consistent with use of norm-based coding children's aftereffects were larger (a) for opposite than non-opposite adapt-test pairs equated for perceptual similarity, and (b) for adaptors far from the average than for adaptors closer to the average. In addition, face identity aftereffects were present by age 5, suggesting adult-like face-space properties by 5, though we did not conduct specific tests to distinguish norm-based from exemplar-based coding in this age group. We conclude that children's poor face identification skills cannot be attributed to a failure to use norm-based coding.
The Attractiveness of Average Faces is not a Generalized Mere Exposure Effect
Publisher: Guilford Publications
Date: 06-2005
The Influence of Averageness on Adults’ Perceptions of Attractiveness
Publisher: SAGE Publications
Date: 19-08-2016
Abstract: Adults who missed early visual input because of congenital cataracts later have deficits in many aspects of face processing. Here we investigated whether they make normal judgments of facial attractiveness. In particular, we studied whether their perceptions are affected normally by a face’s proximity to the population mean, as is true of typically developing adults, who find average faces to be more attractive than most other faces. We compared the judgments of facial attractiveness of 12 cataract-reversal patients to norms established from 36 adults with normal vision. Participants viewed pairs of adult male and adult female faces that had been transformed 50% toward and 50% away from their respective group averages, and selected which face was more attractive. Averageness influenced patients’ judgments of attractiveness, but to a lesser extent than controls. The results suggest that cataract-reversal patients are able to develop a system for representing faces with a privileged position for an average face, consistent with evidence from identity aftereffects. However, early visual experience is necessary to set up the neural architecture necessary for averageness to influence perceptions of attractiveness with its normal potency.
Attractiveness of Own-Race, Other-Race, and Mixed-Race Faces
Publisher: SAGE Publications
Date: 03-2005
DOI: 10.1068/P5191
Abstract: Averaged face composites, which represent the central tendency of a familiar population of faces, are attractive. If this prototypicality contributes to their appeal, then averaged composites should be more attractive when their component faces come from a familiar, own-race population than when they come from a less familiar, other-race population. We compared the attractiveness of own-race composites, other-race composites, and mixed-race composites (where the component faces were from both races). In experiment 1, Caucasian participants rated own-race composites as more attractive than other-race composites, but only for male faces. However, mixed-race (Caucasian/Japanese) composites were significantly more attractive than own-race composites, particularly for the opposite sex. In experiment 2, Caucasian and Japanese participants living in Australia and Japan, respectively, selected the most attractive face from a continuum with exaggerated Caucasian characteristics at one end and exaggerated Japanese characteristics at the other, with intervening images including a Caucasian averaged composite, a mixed-race averaged composite, and a Japanese averaged composite. The most attractive face was, again, a mixed-race composite, for both Caucasian and Japanese participants. In experiment 3, Caucasian participants rated in idual Eurasian faces as significantly more attractive than either Caucasian or Asian faces. Similar results were obtained with composites. Eurasian faces and composites were also rated as healthier than Caucasian or Asian faces and composites, respectively. These results suggest that signs of health may be more important than prototypicality in making average faces attractive.
A critical review of the development of face recognition: Experience is less important than previously believed
Publisher: Informa UK Limited
Date: 03-2012
DOI: 10.1080/02643294.2012.660138
Abstract: Historically, it has been argued that face in iduation develops very slowly, not reaching adult levels until adolescence, with experience being the driving force behind this protracted improvement. Here, we challenge this view based on extensive review of behavioural and neural findings. Results demonstrate qualitative presence of all key phenomena related to face in iduation (encoding of novel faces, holistic processing effects, face-space effects, face-selective responses in neuroimaging) at the earliest ages tested, typically 3-5 years of age and in many cases even infancy. Results further argue for quantitative maturity by early childhood, based on an increasing number of behavioural studies that have avoided the common methodological problem of restriction of range, as well as event-related potential (ERP), but not functional magnetic resonance imaging (fMRI) studies. We raise a new possibility that could account for the discrepant fMRI findings-namely, the use of adult-sized head coils on child-sized heads. We review genetic and innate contributions to face in iduation (twin studies, neonates, visually deprived monkeys, critical periods, perceptual narrowing). We conclude that the role of experience in the development of the mechanisms of face identification has been overestimated. The emerging picture is that the mechanisms supporting face in iduation are mature early, consistent with the social needs of children for reliable person identification in everyday life, and are also driven to an important extent by our evolutionary history.
Now You See It, Now You Don't: Shedding Light on the Thatcher Illusion
Publisher: SAGE Publications
Date: 08-01-2010
Aftereffects support opponent coding of expression
Publisher: American Psychological Association (APA)
Date: 03-2017
DOI: 10.1037/XHP0000322
Abstract: We used aftereffects to investigate the coding mechanisms underlying perception of facial expression. Recent evidence that some dimensions are common to the coding of both expression and identity suggests that the same type of coding system could be used for both attributes. Identity is adaptively opponent coded by pairs of neural populations tuned to opposite extremes of relevant dimensions. Therefore, the authors hypothesized that expression would also be opponent coded. An important line of support for opponent coding is that aftereffects increase with adaptor extremity (distance from an average test face) over the full natural range of possible faces. Previous studies have reported that expression aftereffects increase with adaptor extremity. Critically, however, they did not establish the extent of the natural range and so have not ruled out a decrease within that range that could indicate narrowband, multichannel coding. Here the authors show that expression aftereffects, like identity aftereffects, increase linearly over the full natural range of possible faces and remain high even for impossibly distorted adaptors. These results suggest that facial expression, like face identity, is opponent coded. (PsycINFO Database Record
The average facial expression of a crowd influences impressions of individual expressions.
Publisher: American Psychological Association (APA)
Date: 02-2018
DOI: 10.1037/XHP0000446
Abstract: People can accurately assess the "mood of a crowd" by rapidly extracting the average intensity of all the in idual expressions, when the crowd consists of a set of faces comprising different expressions of the same in idual. Here, we investigate the processes involved when people judge the expression intensity of in idual faces that appear in the context of a more naturalistic crowd of different in iduals' faces. We show that judgments of the intensity of happy and angry expressions for in idual faces are biased toward the group mean expression intensity, even when the faces are all different in iduals. In a second experiment, we demonstrate that this bias is not due to a generic tendency to endorse intermediate intensity expressions more frequently than more extreme intensity expressions. Together, these findings suggest that people integrate ensemble information about the group average expression when they make judgments of in idual faces' expressions. (PsycINFO Database Record
Visual Coding of Human Bodies: Perceptual Aftereffects Reveal Norm-Based, Opponent Coding of Body Identity
Publisher: American Psychological Association (APA)
Date: 04-2013
DOI: 10.1037/A0031568
Abstract: Despite the discovery of body-selective neural areas in occipitotemporal cortex, little is known about how bodies are visually coded. We used perceptual adaptation to determine how body identity is coded. Brief exposure to a body (e.g., anti-Rose) biased perception toward an identity with opposite properties (Rose). Moreover, the size of this aftereffect increased with adaptor extremity, as predicted by norm-based, opponent coding of body identity. A size change between adapt and test bodies minimized the effects of low-level, retinotopic adaptation. These results demonstrate that body identity, like face identity, is opponent coded in higher-level vision. More generally, they show that a norm-based multidimensional framework, which is well established for face perception, may provide a powerful framework for understanding body perception.
Norm-based coding of facial identity in adults with autism spectrum disorder
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.VISRES.2014.11.018
Abstract: It is unclear whether reported deficits in face processing in in iduals with autism spectrum disorders (ASD) can be explained by deficits in perceptual face coding mechanisms. In the current study, we examined whether adults with ASD showed evidence of norm-based opponent coding of facial identity, a perceptual process underlying the recognition of facial identity in typical adults. We began with an original face and an averaged face and then created an anti-face that differed from the averaged face in the opposite direction from the original face by a small amount (near adaptor) or a large amount (far adaptor). To test for norm-based coding, we adapted participants on different trials to the near versus far adaptor, then asked them to judge the identity of the averaged face. We varied the size of the test and adapting faces in order to reduce any contribution of low-level adaptation. Consistent with the predictions of norm-based coding, high functioning adults with ASD (n = 27) and matched typical participants (n = 28) showed identity aftereffects that were larger for the far than near adaptor. Unlike results with children with ASD, the strength of the aftereffects were similar in the two groups. This is the first study to demonstrate norm-based coding of facial identity in adults with ASD.
Autistic Traits are Associated with Less Precise Perceptual Integration of Face Identity
Publisher: Springer Science and Business Media LLC
Date: 03-06-2021
DOI: 10.1007/S10803-021-05111-8
Abstract: Face recognition difficulties are common in autism and could be a consequence of perceptual atypicalities that disrupt the ability to integrate current and prior information. We tested this theory by measuring the strength of serial dependence for faces (i.e. how likely is it that current perception of a face is biased towards a previously seen face) across the broader autism phenotype. Though serial dependence was not weaker in in iduals with more autistic traits, more autistic traits were associated with greater integration of less similar faces. These results suggest that serial dependence is less specialised, and may not operate optimally, in in iduals with more autistic traits and could therefore be a contributing factor to autism-linked face recognition difficulties.
Aftereffects support opponent coding of face gender
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 20-12-2013
DOI: 10.1167/13.14.16
Abstract: Many aspects of faces derived from structural information appear to be neurally represented using norm-based opponent coding. Recently, however, Zhao, Seriès, Hancock, and Bednar (2011) have argued that another aspect with a strong structural component, namely face gender, is instead multichannel coded. Their conclusion was based on finding that face gender aftereffects initially increased but then decreased for adaptors with increasing levels of gender caricaturing. Critically, this interpretation rests on the untested assumption that caricaturing the differences between male and female composite faces increases perceived sexual dimorphism (masculinity/femininity) of faces. We tested this assumption in Study 1 and found that it held for male, but not female faces. A multichannel account cannot, therefore, be ruled out, although a decrease in realism of adaptors was observed that could have contributed to the decrease in aftereffects. However, their aftereffects likely reflect low-level retinotopic adaptation, which was not minimized for most of their participants. In Study 2 we minimized low-level adaptation and found that face gender aftereffects were strongly positively related to the perceived sexual dimorphism of adaptors. We found no decrease for extreme adaptors, despite testing adaptors with higher perceived sexual dimorphism levels than those used by Zhao et al. These results are consistent with opponent coding of higher-level dimensions related to the perception of face gender.
Orientation-sensitivity of face identity aftereffects
Publisher: Elsevier BV
Date: 09-2009
DOI: 10.1016/J.VISRES.2009.07.010
Abstract: Our ability to recognize faces despite their similarity as visual patterns depends on high-level face-coding mechanisms that are strongly tuned to upright faces. If face aftereffects reflect adaptation of these mechanisms, as widely assumed, then they should be sensitive to face orientation. Previous studies have not supported this hypothesis, but have generally used a figural aftereffect paradigm, which may not optimally engage expert face-coding mechanisms. Here, we used an identity aftereffect paradigm, which requires identification of target faces, to provide a stronger test of the hypothesis. We measured identity aftereffects for upright and inverted faces, with and without eliminating low-level retinotopic adaptation. Baseline identification performance was substantially better for upright than inverted faces, confirming that our task tapped orientation-selective face expertise. With orientation varied between participants, aftereffects were almost twice as large for upright as inverted faces, on three different aftereffect measures (change in threshold, change in overall proportion correct, change in perceived identity of the average face). With orientation varied within participants, the results were less clear. We suggest that adaptation of expert face-coding mechanisms can contribute to face identity aftereffects, although the effect may not be very robust.
Abnormal Adaptive Face-Coding Mechanisms in Children with Autism Spectrum Disorder
Publisher: Elsevier BV
Date: 09-2007
DOI: 10.1016/J.CUB.2007.07.065
Abstract: In low-level vision, exquisite sensitivity to variation in luminance is achieved by adaptive mechanisms that adjust neural sensitivity to the prevailing luminance level. In high-level vision, adaptive mechanisms contribute to our remarkable ability to distinguish thousands of similar faces [1]. A clear ex le of this sort of adaptive coding is the face-identity aftereffect [2, 3, 4, 5], in which adaptation to a particular face biases perception toward the opposite identity. Here we investigated face adaptation in children with autism spectrum disorder (ASD) by asking them to discriminate between two face identities, with and without prior adaptation to opposite-identity faces. The ASD group discriminated the identities with the same precision as did the age- and ability-matched control group, showing that face identification per se was unimpaired. However, children with ASD showed significantly less adaptation than did their typical peers, with the amount of adaptation correlating significantly with current symptomatology, and face aftereffects of children with elevated symptoms only one third those of controls. These results show that although children with ASD can learn a simple discrimination between two identities, adaptive face-coding mechanisms are severely compromised, offering a new explanation for previously reported face-perception difficulties [6, 7, 8] and possibly for some of the core social deficits in ASD [9, 10].
Sex-specific norms code face identity
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 03-01-2011
DOI: 10.1167/11.1.1
Abstract: Face identity aftereffects suggest that an average face, which is continuously updated by experience, functions as a norm for coding identity. Sex-contingent figural face aftereffects indicate that different norms are maintained for male and female faces but do not directly implicate them in coding identity. Here, we investigated whether sex-specific norms are used to code the identities of male and female faces or whether a generic, androgynous norm is used for all faces. We measured identity aftereffects for adapt-test pairs that were opposite relative to a sex-specific average and pairs that were opposite relative to an androgynous average. Identity aftereffects are generally larger for adapt-test pairs that lie opposite an average face, which functions as a norm for coding identity, than those that do not. Therefore, we reasoned that whichever average gives the larger aftereffect would be closer to the true psychological norm. Aftereffects were substantially and significantly larger for pairs that lie opposite a sex-specific than an androgynous average. This difference remained significant after correcting for differences in test trajectory length. These results indicate that, despite the common structure shared by all faces, identity is coded using sex-specific norms. We suggest that the use of category-specific norms may increase coding efficiency and help us discriminate thousands of faces despite their similarity as patterns.
Four-to-six-year-old children use norm-based coding in face-space
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 05-2010
DOI: 10.1167/10.5.18
Abstract: Children's performance on face perception tests does not reach adult levels until adolescence, a result which, a priori, could be due to qualitative change in face mechanisms with age, quantitative change in these mechanisms, or improvements in general cognitive abilities that are not face-specific (e.g., memory, attention). In adults, the major functional mechanisms of face recognition include holistic/configural processing and face-space coding. Previous research has established that holistic/configural processing is present by 4-6 years of age. Very little, however, is known about face-space coding in children. Here, we demonstrate that 4-6-year-old children show adaptation aftereffects for figural distortions (expanded/contracted, eyes up/down), providing the first evidence of aftereffects for identity-relevant information in children younger than 8 years. We also show that in 4-5 year-olds, as in adults, face aftereffects are stronger for adaptors far from the average (extreme distortions) than for adaptors closer to the average (mild distortions). This result provides the first compelling evidence that face-space coding is norm-based in children younger than 8 years of age, and rules out a qualitative shift from exemplar-based to norm-based coding as the source of developmental improvement in face identification performance beyond preschool age.
Adults’ facial impressions of children’s niceness, but not shyness, show modest accuracy
Publisher: SAGE Publications
Date: 23-09-2020
Abstract: Lay wisdom warns against “judging a book by its cover.” However, facial first impressions influence people’s behaviour towards others, so it is critical that we understand whether these impressions are at all accurate. Understanding impressions of children’s faces is particularly important because these impressions can have social consequences during a crucial time of development. Here, we examined the accuracy of two traits that capture the most variance in impressions of children’s faces, niceness and shyness. We collected face images and parental reports of actual niceness/shyness for 86 children (4–11 years old). Different images of the same person can lead to different impressions, and so we employed a novel approach by obtaining impressions from five images of each child. These images were ambient, representing the natural variability in faces. Adult strangers rated the faces for niceness (Study 1) or shyness (Study 2). Niceness impressions were modestly accurate for different images of the same child, regardless of whether these images were presented in idually or simultaneously as a group. Shyness impressions were not accurate, for images presented either in idually or as a group. Together, these results demonstrate modest accuracy in adults’ impressions of niceness, but not shyness, from children’s faces. Furthermore, our results reveal that this accuracy can be captured by images which contain natural face variability, and holds across different images of the same child’s face. These results invite future research into the cues and causal mechanisms underlying this link between facial impressions of niceness and nice behaviour in children.
Face recognition impairments despite normal holistic processing and face space coding: Evidence from a case of developmental prosopagnosia
Publisher: Informa UK Limited
Date: 12-2010
DOI: 10.1080/02643294.2011.613372
Abstract: Holistic processing and face space coding are widely considered primary perceptual mechanisms behind good face recognition. Here, however, we present the case of S.P., a developmental prosopagnosic who demonstrated severe impairments in face memory and face perception, yet showed normal holistic processing and face space coding. Across three composite experiments, S.P. showed normal-strength holistic processing for upright faces and no composite effect for inverted faces. Across five aftereffect experiments, S.P. showed normal-sized face aftereffects, which derived normally from face space rather than shape-generic mechanisms. The case of S.P. implies: (a) normal holistic processing and face space coding can be insufficient for good face recognition even when present in combination and (b) the focus of recent literature on holistic processing and face space should be expanded to include other potential face processing mechanisms (e.g., part-based processing). Our article also highlights the importance of internal task reliability in drawing inferences from single-case studies.
Individual differences in adaptive coding of face identity are linked to individual differences in face recognition ability
Publisher: American Psychological Association (APA)
Date: 2014
DOI: 10.1037/A0035939
Abstract: Despite their similarity as visual patterns, we can discriminate and recognize many thousands of faces. This expertise has been linked to 2 coding mechanisms: holistic integration of information across the face and adaptive coding of face identity using norms tuned by experience. Recently, in idual differences in face recognition ability have been discovered and linked to differences in holistic coding. Here we show that they are also linked to in idual differences in adaptive coding of face identity, measured using face identity aftereffects. Identity aftereffects correlated significantly with several measures of face-selective recognition ability. They also correlated marginally with own-race face recognition ability, suggesting a role for adaptive coding in the well-known other-race effect. More generally, these results highlight the important functional role of adaptive face-coding mechanisms in face expertise, taking us beyond the traditional focus on holistic coding mechanisms.
Serial dependence of facial identity for own- and other-race faces
Publisher: SAGE Publications
Date: 12-2021
DOI: 10.1177/17470218211059430
Abstract: It is well established that in iduals are better at recognising faces of their own-race compared with other-races however, there is ongoing debate regarding the perceptual mechanisms that may be involved and therefore sensitive to face-race. Here, we ask whether serial dependence of facial identity, a bias where the perception of a face’s identity is biased towards a previously presented face, shows an other-race effect. Serial dependence is associated with face recognition ability and appears to operate on high-level, face-selective representations, like other candidate mechanisms (e.g., holistic processing). We therefore expected to find an other-race effect for serial dependence for our Caucasian and Asian participants. While participants showed robust effects of serial dependence for all faces, only Caucasian participants showed stronger serial dependence for own-race faces. Intriguingly, we found that in idual variation in own-race, but not other-race, serial dependence was significantly associated with face recognition abilities. Preliminary evidence also suggested that other-race contact is associated with other-race serial dependence. In conclusion, though we did not find an overall difference in serial dependence for own- versus other-race faces in both participant groups, our results highlight that this bias may be functionally different for own- versus other-race faces and sensitive to racial experience.
Fitting the Mind to the World: Face Adaptation and Attractiveness Aftereffects
Publisher: SAGE Publications
Date: 11-2003
DOI: 10.1046/J.0956-7976.2003.PSCI_1465.X
Abstract: Average faces are attractive, but what is average depends on experience. We examined the effect of brief exposure to consistent facial distortions on what looks normal (average) and what looks attractive. Adaptation to a consistent distortion shifted what looked most normal, and what looked most attractive, toward that distortion. These normality and attractiveness aftereffects occurred when the adapting and test faces differed in orientation by 90° (∓45° vs. −45°), suggesting adaptation of high-level neurons whose coding is not strictly retino-topic. Our results suggest that perceptual adaptation can rapidly recalibrate people's preferences to fit the faces they see. The results also suggest that average faces are attractive because of their central location in a distribution of faces (i.e., prototypicality), rather than because of any intrinsic appeal of particular physical characteristics. Recalibration of preferences may have important consequences, given the powerful effects of perceived attractiveness on person perception, mate choice, social interactions, and social outcomes for in iduals.
Facial Expressions of Threat Influence Perceived Gaze Direction in 8 Year-Olds
Publisher: Public Library of Science (PLoS)
Date: 14-11-2012
Adaptive face space coding in congenital prosopagnosia: Typical figural aftereffects but abnormal identity aftereffects
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2011.09.039
Abstract: People with congenital prosopagnosia (CP) report difficulty recognising faces in everyday life and perform poorly on face recognition tests. Here, we investigate whether impaired adaptive face space coding might contribute to poor face recognition in CP. To pinpoint how adaptation may affect face processing, a group of CPs and matched controls completed two complementary face adaptation tasks: the figural aftereffect, which reflects adaptation to general distortions of shape, and the identity aftereffect, which directly taps the mechanisms involved in the discrimination of different face identities. CPs displayed a typical figural aftereffect, consistent with evidence that they are able to process some shape-based information from faces, e.g., cues to discriminate sex. CPs also demonstrated a significant identity aftereffect. However, unlike controls, CPs impression of the identity of the neutral average face was not significantly shifted by adaptation, suggesting that adaptive coding of identity is abnormal in CP. In sum, CPs show reduced aftereffects but only when the task directly taps the use of face norms used to code in idual identity. This finding of a reduced face identity aftereffect in in iduals with severe face recognition problems is consistent with suggestions that adaptive coding may have a functional role in face recognition.
Insights into the development of face recognition mechanisms revealed by face aftereffects
Publisher: Wiley
Date: 11-10-2011
DOI: 10.1111/J.2044-8295.2011.02066.X
Abstract: An important question in person perception is how we acquire the perceptual/cognitive mechanisms that characterize adult expertise. Children's performance on face recognition tests improves dramatically between age 4 and adolescence suggesting that our face recognition system may change during childhood. Yet, the source of this improvement is controversial. In this review, we consider whether changes in the way identity is represented/coded in face space could contribute to this age-related improvement. Face aftereffects have been extensively applied to studying face coding in adults and more recently they have been applied to studying the mechanisms of face coding in children. Face aftereffects are temporary distortions of perception induced by exposure to faces and are thought to reflect the mechanisms underlying face perception. Face aftereffect techniques have revealed that children as young as 4 years of age show evidence of adult-like face space organization, with opponent coding of face dimensions. These findings are consistent with an emerging picture that the key mechanisms of face perception are present early in childhood.
Broadly tuned, view-specific coding of face shape: Opposing figural aftereffects can be induced in different views
Publisher: Elsevier BV
Date: 11-2007
DOI: 10.1016/J.VISRES.2007.08.018
Abstract: Face aftereffects are sensitive to changes in viewpoint, suggesting view-specific face coding, yet are not entirely eliminated by changes in viewpoint, suggesting view-invariance. To determine whether broad view-tuning can account for these findings we measured the reduction of a figural face aftereffect induced in one view by concurrent adaptation to an opposite distortion in a second viewpoint, varying the angle between these views. To the degree that the same neural population codes both viewpoints, the opposing aftereffects should cancel. Cancellation increased monotonically as the angle between two adapting views decreased, consistent with broadly tuned, view-specific coding of face shape.
Orientation-Contingent Face Aftereffects and Implications for Face-Coding Mechanisms
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.CUB.2004.11.053
Abstract: Humans have an impressive ability to discriminate between faces despite their similarity as visual patterns. This expertise relies on configural coding of spatial relations between face features and/or holistic coding of overall facial structure. These expert face-coding mechanisms appear to be engaged most effectively by upright faces, with inverted faces engaging primarily feature-coding mechanisms. We show that opposite figural aftereffects can be induced simultaneously for upright and inverted faces, demonstrating that distinct neural populations code upright and inverted faces. This result also suggests that expert (upright) face-coding mechanisms can be selectively adapted. These aftereffects occur for judgments of face normality and face gender and are robust to changes in face size, ruling out adaptation of low-level, retinotopically organized coding mechanisms. Our results suggest a resolution of a paradox in the face recognition literature. Neuroimaging studies have found surprisingly little orientation selectivity in the fusiform face area (FFA) despite evidence that this region plays a role in expert face coding and that expert face-coding mechanisms are selectively engaged by upright faces. Our results, demonstrating orientation-contingent adaptation of face-coding mechanisms, suggest that the FFA's apparent lack of orientation selectivity may be an artifact of averaging across distinct populations within the FFA that respond to upright and inverted faces.
Face identity aftereffects increase monotonically with adaptor extremity over, but not beyond, the range of natural faces
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.VISRES.2014.01.007
Abstract: Face identity aftereffects have been used to test theories of the neural coding underlying expert face recognition. Previous studies reported larger aftereffects for adaptors that are morphed further from the average face than for adaptors closer to the average, which appeared to support opponent coding along face-identity dimensions. However, only two levels were tested and it is not clear where they were located relative to the range of naturally occurring faces. This range is of interest given the functional need of the visual system both to produce good discrimination of real everyday faces and to process novel kinds of faces that we may encounter. Here, Experiment 1 establishes the boundary of faces judged as being able to occur in everyday life. Experiment 2 then shows that aftereffects increase with adaptor extremity up to this natural-range boundary, drop significantly immediately outside the boundary, and then remain stable with no drop towards zero even for highly distorted adaptors far beyond the boundary. Computational modelling shows that this unexpected pattern cannot be explained either by a simple opponent or by a classic multichannel model. However, its qualitative features can be captured either by a combination of opponent and multichannel coding (raising the possibility that not all identity-related face dimensions are opponent coded), or by a 3-pool model containing two S-shaped-response channels and a central bell-shaped channel around the average face (raising the possibility of unexpected similarities with coding of eye and head direction).
Face and body recognition show similar improvement during childhood
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.JECP.2015.02.011
Abstract: Adults are proficient in extracting identity cues from faces. This proficiency develops slowly during childhood, with performance not reaching adult levels until adolescence. Bodies are similar to faces in that they convey identity cues and rely on specialized perceptual mechanisms. However, it is currently unclear whether body recognition mirrors the slow development of face recognition during childhood. Recent evidence suggests that body recognition develops faster than face recognition. Here we measured body and face recognition in 6- and 10-year-old children and adults to determine whether these two skills show different amounts of improvement during childhood. We found no evidence that they do. Face and body recognition showed similar improvement with age, and children, like adults, were better at recognizing faces than bodies. These results suggest that the mechanisms of face and body memory mature at a similar rate or that improvement of more general cognitive and perceptual skills underlies improvement of both face and body recognition.
Evidence for a kernel of truth in children’s facial impressions of children’s niceness, but not shyness.
Publisher: American Psychological Association (APA)
Date: 11-2021
DOI: 10.1037/DEV0001240
Abstract: Adults teach children not to "judge a book by its cover." However, adults make rapid judgments of character from a glance at a child's face. These impressions can be modestly accurate, suggesting that adults may be sensitive to valid signals of character in children's faces. However, it is not clear whether such sensitivity requires decades of social experience, in line with the development of other face-processing abilities (e.g., facial emotion recognition), or whether this sensitivity emerges relatively early, in childhood. An important theoretical question therefore, is whether or not children's impressions are at all accurate. Here, we examined the accuracy in children's impressions of niceness and shyness from children's faces. Children (aged 7-12 years, ∼90% Caucasian) and adults rated 84 unfamiliar children's faces (aged 4-11 years, 48 female, ∼80% Caucasian) for niceness (Study 1) or shyness (Study 2). To measure accuracy, we correlated facial impressions with parental responses to well-established questionnaires about the actual niceness/shyness of those children in the images. Overall, children and adults formed highly similar niceness (r = .94) and shyness (r = .84) impressions. Children also showed mature impression accuracy: Children and adults formed modestly accurate niceness impressions, across different images of the same child's face. Neither children nor adults showed evidence for accurate shyness impressions. Together, these results suggest that children's impressions are relatively mature by middle childhood. Furthermore, these results demonstrate that any mechanisms driving accurate niceness impressions are in place by 7 years, and potentially before. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Perceptual adaptation helps us identify faces
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.VISRES.2010.03.003
Abstract: Adaptation is a fundamental property of perceptual processing. In low-level vision, it can calibrate perception to current inputs, increasing coding efficiency and enhancing discrimination around the adapted level. Adaptation also occurs in high-level vision, as illustrated by face aftereffects. However, the functional consequences of face adaptation remain uncertain. Here we investigated whether adaptation can enhance identification performance for faces from an adapted, relative to an unadapted, population. Five minutes of adaptation to an average Asian or Caucasian face reduced identification thresholds for faces from the adapted relative to the unadapted race. We replicated this interaction in two studies, using different participants, faces and adapting procedures. These results suggest that adaptation has a functional role in high-level, as well as low-level, visual processing. We suggest that adaptation to the average of a population may reduce responses to common properties shared by all members of the population, effectively orthogonalizing identity vectors in a multi-dimensional face space and freeing neural resources to code distinctive properties, which are useful for identification.
Adaptor gaze direction affects the magnitude of face identity aftereffects.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 09-2015
DOI: 10.1167/15.12.1195
Gaze direction affects the magnitude of face identity aftereffects
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 20-02-2015
DOI: 10.1167/15.2.22
Abstract: The face perception system partly owes its efficiency to adaptive mechanisms that constantly recalibrate face coding to our current diet of faces. Moreover, faces that are better attended produce more adaptation. Here, we investigated whether the social cues conveyed by a face can influence the amount of adaptation that face induces. We compared the magnitude of face identity aftereffects induced by adaptors with direct and averted gazes. We reasoned that faces conveying direct gaze may be more engaging and better attended and thus produce larger aftereffects than those with averted gaze. Using an adaptation duration of 5 s, we found that aftereffects for adaptors with direct and averted gazes did not differ (Experiment 1). However, when processing demands were increased by reducing adaptation duration to 1 s, we found that gaze direction did affect the magnitude of the aftereffect, but in an unexpected direction: Aftereffects were larger for adaptors with averted rather than direct gaze (Experiment 2). Eye tracking revealed that differences in looking time to the faces between the two gaze directions could not account for these findings. Subsequent ratings of the stimuli (Experiment 3) showed that adaptors with averted gaze were actually perceived as more expressive and interesting than adaptors with direct gaze. Therefore it appears that the averted-gaze faces were more engaging and better attended, leading to larger aftereffects. Overall, our results suggest that naturally occurring facial signals can modulate the adaptive impact a face exerts on our perceptual system. Specifically, the faces that we perceive as most interesting also appear to calibrate the organization of our perceptual system most strongly.
Are average and symmetric faces attractive to infants Discrimination and looking preferences
Publisher: SAGE Publications
Date: 03-2002
DOI: 10.1068/P3129
Abstract: Young infants prefer to look at faces that adults find attractive, suggesting a biological basis for some face preferences. However, the basis for infant preferences is not known. Adults find average and symmetric faces attractive. We examined whether 5–8-month-old infants discriminate between different levels of averageness and symmetry in faces, and whether they prefer to look at faces with higher levels of these traits. Each infant saw 24 pairs of female faces. Each pair consisted of two versions of the same face differing either in averageness (12 pairs) or symmetry (12 pairs). Data from the mothers confirmed that adults preferred the more average and more symmetric versions in each pair. The infants were sensitive to differences in both averageness and symmetry, but showed no looking preference for the more average or more symmetric versions. On the contrary, longest looks were significantly longer for the less average versions, and both longest looks and first looks were marginally longer for the less symmetric versions. Mean looking times were also longer for the less average and less symmetric versions, but those differences were not significant. We suggest that the infant looking behaviour may reflect a novelty preference rather than an aesthetic preference.
Ensemble coding of face identity is present but weaker in congenital prosopagnosia
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2018.02.019
Abstract: In iduals with congenital prosopagnosia (CP) are impaired at identifying in idual faces but do not appear to show impairments in extracting the average identity from a group of faces (known as ensemble coding). However, possible deficits in ensemble coding in a previous study (CPs n = 4) may have been masked because CPs relied on pictorial (image) cues rather than identity cues. Here we asked whether a larger s le of CPs (n = 11) would show intact ensemble coding of identity when availability of image cues was minimised. Participants viewed a "set" of four faces and then judged whether a subsequent in idual test face, either an exemplar or a "set average", was in the preceding set. Ensemble coding occurred when matching (vs. mismatching) averages were mistakenly endorsed as set members. We assessed both image- and identity-based ensemble coding, by varying whether test faces were either the same or different images of the identities in the set. CPs showed significant ensemble coding in both tasks, indicating that their performance was independent of image cues. As a group, CPs' ensemble coding was weaker than controls in both tasks, consistent with evidence that perceptual processing of face identity is disrupted in CP. This effect was driven by CPs (n= 3) who, in addition to having impaired face memory, also performed particularly poorly on a measure of face perception (CFPT). Future research, using larger s les, should examine whether deficits in ensemble coding may be restricted to CPs who also have substantial face perception deficits.
Sex-typicality and attractiveness: Are supermale and superfemale faces super-attractive
Publisher: Wiley
Date: 02-2000
Abstract: Many animals find extreme versions of secondary sexual characteristics attractive, and such preferences can enhance reproductive success (Andersson, 1994). We hypothesized, therefore, that extreme versions of sex-typical traits may be attractive in human faces. We created supermale and superfemale faces by exaggerating all spatial differences between an average male and an average female face. In Expt 1 the male average was preferred to a supermale (50% exaggeration of differences from the female average). There was no clear preference for the female average or the superfemale (50% exaggeration). In Expt 2, participants chose the most attractive face from sets of images containing feminized as well as masculinized images for each sex, and spanning a wider range of exaggeration levels than in Expt 1. Chinese sets were also shown, to see whether similar preferences would occur for a less familiar race (participants were Caucasian). The most attractive female image was significantly feminized for faces of both races. However, the most attractive male image for both races was also significantly feminized. These results indicate that feminization, rather than sex exaggeration per se, is attractive in human faces, and they corroborate similar findings by Perrett et al. (1998).
Children's Dynamic Use of Face- and Behavior-Based Cues in an Economic Trust Game
Publisher: American Psychological Association (APA)
Date: 12-2022
DOI: 10.1037/DEV0001438
Abstract: Who do children trust? We investigated the extent to which children use face-based versus behavior-based cues when deciding whom to trust in a multiturn economic trust game. Children's (
The role of higher level adaptive coding mechanisms in the development of face recognition
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.JECP.2009.05.009
Abstract: Developmental improvements in face identity recognition ability are widely documented, but the source of children's immaturity in face recognition remains unclear. Differences in the way in which children and adults visually represent faces might underlie immaturities in face recognition. Recent evidence of a face identity aftereffect (FIAE), in which adaptation (exposure) to a particular identity causes a previously neutral face to take on the computationally opposite identity, suggests that adults code faces in an opponent fashion relative to an average face. One previous study showed comparable FIAEs in 8-year-olds and adults but did not demonstrate that adaptation was selective for high-level representations in both groups. Using a developmentally appropriate FIAE task, we investigated whether children show adult-like adaptation for facial identity when adapting and test images differ in size. Both age groups showed an equivalent FIAE, suggesting that qualitative changes in the use of higher level adaptive coding mechanisms do not drive the developmental improvements in face recognition ability, at least from 8 years of age.
Reduced adaptability, but no fundamental disruption, of norm-based face-coding mechanisms in cognitively able children and adolescents with autism
Publisher: Elsevier BV
Date: 09-2014
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2014.07.030
Abstract: Faces are adaptively coded relative to visual norms that are updated by experience. This coding is compromised in autism and the broader autism phenotype, suggesting that atypical adaptive coding of faces may be an endophenotype for autism. Here we investigate the nature of this atypicality, asking whether adaptive face-coding mechanisms are fundamentally altered, or simply less responsive to experience, in autism. We measured adaptive coding, using face identity aftereffects, in cognitively able children and adolescents with autism and neurotypical age- and ability-matched participants. We asked whether these aftereffects increase with adaptor identity strength as in neurotypical populations, or whether they show a different pattern indicating a more fundamental alteration in face-coding mechanisms. As expected, face identity aftereffects were reduced in the autism group, but they nevertheless increased with adaptor strength, like those of our neurotypical participants, consistent with norm-based coding of face identity. Moreover, their aftereffects correlated positively with face recognition ability, consistent with an intact functional role for adaptive coding in face recognition ability. We conclude that adaptive norm-based face-coding mechanisms are basically intact in autism, but are less readily calibrated by experience.
Children show neural sensitivity to facial trustworthiness as measured by fast periodic visual stimulation
Publisher: Elsevier BV
Date: 02-2023
Fitting the child's mind to the world : adaptive norm-based coding of facial identity in 8-year-olds
Publisher: Wiley
Date: 28-06-2008
DOI: 10.1111/J.1467-7687.2008.00706.X
Abstract: In adults, facial identity is coded by opponent processes relative to an average face or norm, as evidenced by the face identity aftereffect: adapting to a face biases perception towards the opposite identity, so that a previously neutral face (e.g. the average) resembles the identity of the computationally opposite face. We investigated whether children as young as 8 use adaptive norm-based coding to represent faces, a question of interest because 8-year-olds are less accurate than adults at recognizing faces and do not show the adult neural markers of face expertise. We found comparable face identity aftereffects in 8-year-olds and adults: perception of identity in both groups shifted in the direction predicted by norm-based coding. This finding suggests that, by 8 years of age, the adaptive computational mechanisms used to code facial identity are like those of adults and hence that children's immaturities in face processing arise from another source.
Beyond opponent coding of facial identity
Publisher: American Psychological Association (APA)
Date: 02-2018
DOI: 10.1037/XHP0000427
Abstract: Face identity can be represented in a multidimensional space centered on the average. It has been argued that the average acts as a perceptual norm, with the norm coded implicitly by balanced activation in pairs of channels that respond to opposite extremes of face dimensions (two-channel model). In Experiment 1 we used face identity aftereffects to distinguish this model from a narrow-band multichannel model with no norm. We show that as adaptors become more extreme, aftereffects initially increase sharply and then plateau. Crucially there is no decrease, ruling out narrow-band multichannel coding, but consistent with a two-channel norm-based model. However, these results leave open the possibility that there may be a third channel, tuned explicitly to the norm (three-channel model). In Experiment 2 we show that alternating adaptation widens the range identified as the average whereas adaptation to the average narrows the range, consistent with the three-channel model. Explicit modeling confirmed the three-channel model as the best fit for the combined data from both experiments. However, a two-channel model with decision criteria allowed to vary between adapting conditions, also provided a very good fit. These results support opponent, norm-based coding of face identity with additional explicit coding of the norm. (PsycINFO Database Record
Children's Face Identity Representations Are No More View Specific Than Those of Adults
Publisher: American Psychological Association (APA)
Date: 2013
DOI: 10.1037/A0029141
Abstract: Face recognition performance improves during childhood, not reaching adult levels until late adolescence, yet the source of this improvement is unclear. Recognition of faces across changes in viewpoint appears particularly slow to develop. Poor cross-view recognition suggests that children's face representations may be more view specific than those of adults and is consistent with arguments that extensive experience with faces may be required to form representations that are robust to view changes. We conducted the first direct test of the view specificity of children's face representations by using face aftereffects to investigate whether children's face aftereffects transfer across changes in viewpoint. Using both the figural aftereffect (E1) and the identity aftereffect (E2) we showed that 8-year-old children's aftereffects transferred across substantial changes in viewpoint and that children did not differ from adults in the amount of transfer across viewpoint. These results suggest that children's coding of identity is no more view specific than that of adults and are consistent with a growing body of evidence indicating that the key perceptual mechanisms of face recognition emerge early in life.
Four year-olds use norm-based coding for face identity
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.COGNITION.2013.01.008
Abstract: Norm-based coding, in which faces are coded as deviations from an average face, is an efficient way of coding visual patterns that share a common structure and must be distinguished by subtle variations that define in iduals. Adults and school-aged children use norm-based coding for face identity but it is not yet known if pre-school aged children also use norm-based coding. We reasoned that the transition to school could be critical in developing a norm-based system because school places new demands on children's face identification skills and substantially increases experience with faces. Consistent with this view, face identification performance improves steeply between ages 4 and 7. We used face identity aftereffects to test whether norm-based coding emerges between these ages. We found that 4 year-old children, like adults, showed larger face identity aftereffects for adaptors far from the average than for adaptors closer to the average, consistent with use of norm-based coding. We conclude that experience prior to age 4 is sufficient to develop a norm-based face-space and that failure to use norm-based coding cannot explain 4 year-old children's poor face identification skills.
Reduced adaptability, but no fundamental disruption, of norm‐based face coding following early visual deprivation from congenital cataracts
Publisher: Wiley
Date: 29-01-2016
DOI: 10.1111/DESC.12384
Abstract: Faces are adaptively coded relative to visual norms that are updated by experience, and this adaptive coding is linked to face recognition ability. Here we investigated whether adaptive coding of faces is disrupted in in iduals (adolescents and adults) who experience face recognition difficulties following visual deprivation from congenital cataracts in infancy. We measured adaptive coding using face identity aftereffects, where smaller aftereffects indicate less adaptive updating of face-coding mechanisms by experience. We also examined whether the aftereffects increase with adaptor identity strength, consistent with norm-based coding of identity, as in typical populations, or whether they show a different pattern indicating some more fundamental disruption of face-coding mechanisms. Cataract-reversal patients showed significantly smaller face identity aftereffects than did controls (Experiments 1 and 2). However, their aftereffects increased significantly with adaptor strength, consistent with norm-based coding (Experiment 2). Thus we found reduced adaptability but no fundamental disruption of norm-based face-coding mechanisms in cataract-reversal patients. Our results suggest that early visual experience is important for the normal development of adaptive face-coding mechanisms.
How is facial expression coded?
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 02-01-2015
DOI: 10.1167/15.1.1
Abstract: Facial expression is theorized to be visually represented in a multidimensional expression space, relative to a norm. This norm-based coding is typically argued to be implemented by a two-pool opponent coding system. However, the evidence supporting the opponent coding of expression cannot rule out the presence of a third channel tuned to the center of each coded dimension. Here we used a paradigm not previously applied to facial expression to determine whether a central-channel model is necessary to explain expression coding. Participants identified expressions taken from a fear/antifear trajectory, first at baseline and then in two adaptation conditions. In one condition, participants adapted to the expression at the center of the trajectory. In the other condition, participants adapted to alternating images from the two ends of the trajectory. The range of expressions that participants perceived as lying at the center of the trajectory narrowed in both conditions, a pattern that is not predicted by the central-channel model but can be explained by the opponent-coding model. Adaptation to the center of the trajectory also increased identification of both fear and antifear, which may indicate a functional benefit for adaptive coding of facial expression.
Children's face coding is norm-based rather than exemplar-based: Evidence from face identity aftereffects
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 06-08-2010
DOI: 10.1167/10.7.580
Individual differences in adaptive norm-based coding and holistic coding are associated yet each contributes uniquely to unfamiliar face recognition ability
Publisher: American Psychological Association (APA)
Date: 2017
DOI: 10.1037/XHP0000265
Abstract: We can discriminate and recognize many faces, despite their visual similarity. In idual differences in this ability have been linked to 2 face coding mechanisms: adaptive norm-based coding of identity and holistic coding. However, it is not yet known whether these mechanisms are distinct. Nor is it known whether they make unique contributions to face recognition ability because no studies have measured the operation of both these mechanisms in the same in iduals. We measured in idual differences in both the strength of adaptive norm-based coding (with a face identity aftereffect task) and holistic coding (with a composite face task). For the first time, we show that these 2 mechanisms are positively and moderately associated and that each makes significant unique contributions to unfamiliar face recognition ability (Cambridge Face Memory Test [CMFT]). Importantly, these relationships were face-specific. We also show that the combined contribution of these mechanisms to face recognition performance is significantly larger than the contribution of nonface recognition memory, consistent with the view that face recognition relies on the operation of face-sensitive mechanisms. Overall, our results raise intriguing questions regarding what these mechanisms may have in common, and what other mechanisms support face recognition performance. (PsycINFO Database Record
Individual Differences in Serial Dependence of Facial Identity are Associated with Face Recognition Abilities
Publisher: Springer Science and Business Media LLC
Date: 02-12-2019
DOI: 10.1038/S41598-019-53282-3
Abstract: Serial dependence is a perceptual bias where current perception is biased towards prior visual input. This bias occurs when perceiving visual attributes, such as facial identity, and has been argued to play an important functional role in vision, stabilising the perception of objects through integration. In face identity recognition, this bias could assist in building stable representations of facial identity. If so, then in idual variation in serial dependence could contribute to face recognition ability. To investigate this possibility, we measured both the strength of serial dependence and the range over which in iduals showed this bias (the tuning) in 219 adults, using a new measure of serial dependence of facial identity. We found that better face recognition was associated with stronger serial dependence and narrower tuning, that is, showing serial dependence primarily when sequential faces were highly similar. Serial dependence tuning was further found to be a significant predictor of face recognition abilities independently of both object recognition and face identity aftereffects. These findings suggest that the extent to which serial dependence is used selectively for similar faces is important to face recognition. Our results are consistent with the view that serial dependence plays a functional role in face recognition.
Adaptive face coding contributes to individual differences in facial expression recognition independently of affective factors
Publisher: American Psychological Association (APA)
Date: 04-2018
DOI: 10.1037/XHP0000463
Abstract: There are large, reliable in idual differences in the recognition of facial expressions of emotion across the general population. The sources of this variation are not yet known. We investigated the contribution of a key face perception mechanism, adaptive coding, which calibrates perception to optimize discrimination within the current perceptual "diet." We expected that a facial expression system that readily recalibrates might boost sensitivity to variation among facial expressions, thereby enhancing recognition ability. We measured adaptive coding strength with an established facial expression aftereffect task and measured facial expression recognition ability with 3 tasks optimized for the assessment of in idual differences. As expected, expression recognition ability was positively associated with the strength of facial expression aftereffects. We also asked whether in idual variation in affective factors might contribute to expression recognition ability, given that clinical levels of such traits have previously been linked to ability. Expression recognition ability was negatively associated with self-reported anxiety but not with depression, mood, or degree of autism-like or empathetic traits. Finally, we showed that the perceptual factor of adaptive coding contributes to variation in expression recognition ability independently of affective factors. (PsycINFO Database Record
Reduced face identity aftereffects in relatives of children with autism
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2012.08.019
Abstract: Autism is a pervasive developmental condition with complex aetiology. To aid the discovery of genetic mechanisms, researchers have turned towards identifying potential endophenotypes - subtle neurobiological or neurocognitive traits present in in iduals with autism and their "unaffected" relatives. Previous research has shown that relatives of in iduals with autism exhibit face processing atypicalities, which are similar in nature albeit of lesser degree, to those found in children and adults with autism. Yet very few studies have examined the underlying mechanisms responsible for such atypicalities. Here, we investigated whether atypicalities in adaptive norm-based coding of faces are present in relatives of children with autism, similar to those previously reported in children with autism. To test this possibility, we administered a face identity aftereffect task in which adaptation to a particular face biases perception towards the opposite identity, so that a previously neutral face (i.e., the average face) takes on the computationally opposite identity. Parents and siblings of in iduals with autism showed smaller aftereffects compared to parents and siblings of typically developing children, especially so when the adapting stimuli were located further away from the average face. In addition, both groups showed stronger aftereffects for adaptors far from the average than for adaptors closer to the average. These results suggest that, in relatives of children with autism, face-coding mechanism are similar (i.e., norm-based) but less efficient than in relatives of typical children. This finding points towards the possibility that diminished adaptive mechanisms might represent a neurocognitive endophenotype for autism.
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