Aspects Of Face Processing Research Articles

Face-selective multi-unit activity in the proximity of the FFA modulated by facial expression stimuli

When we see someone's face, our brain usually effortlessly extracts a variety of information such as facial identity, expression, or gaze direction. While it is widely accepted that dedicated subsystems are responsible for different aspects of face processing, how these subsystems work together is not yet fully understood. To this extent, one of the most explored questions is whether and if so, to what extent facial expression processing interacts with other stages of facial processing. In the present study, we report a rare case of a patient for whom we were able to record multi-unit activity (MUA) in the proximity of the fusiform face area (FFA) while two out of four recorded multi-units were face-selective. In our experiment, the human subject was shown images of neutral and fearful faces as well as everyday objects and frightening images of natural disaster. We found that activity of both face-selective units was modulated by facial expression stimuli, starting at about 150 ms from stimulus onset. For both facial conditions we observed abrupt increase in firing rate with a simultaneous peak, suggesting that this activity and the modulation by facial expression stimuli likely reflected feed-forward processing. Interestingly, while in one multi-unit, the firing rate for fearful faces was higher than for neutral faces, in the other multi-units the polarity was reversed. Finally, modulation in the face-selective units was specific to emotional facial stimuli, but not to emotional stimuli in general. The present multi-unit results, albeit obtained only for several multi-units, nevertheless are potentially valuable for understanding mechanisms of facial processing in humans.

Multimodal Evidence of Atypical Processing of Eye Gaze and Facial Emotion in Children With Autistic Traits.

According to the shared signal hypothesis (SSH) the impact of facial expressions on emotion processing partially depends on whether the gaze is directed toward or away from the observer. In autism spectrum disorder (ASD) several aspects of face processing have been found to be atypical, including attention to eye gaze and the identification of emotional expressions. However, there is little research on how gaze direction affects emotional expression processing in typically developing (TD) individuals and in those with ASD. This question is investigated here in two multimodal experiments. Experiment 1 required processing eye gaze direction while faces differed in emotional expression. Forty-seven children (aged 9–12 years) participated. Their Autism Diagnostic Observation Schedule (ADOS) scores ranged from 0 to 6 in the experiment. Event-related potentials (ERPs) were sensitive to gaze direction and emotion, but emotion processing did not depend on gaze direction. However, for angry faces the gaze direction effect on the N170 amplitude, as typically observed in TD individuals, diminished with increasing ADOS score. For neutral expressions this correlation was not significant. Experiment 2 required explicit emotion classifications in a facial emotion composite task while eye gaze was manipulated incidentally. A group of 22 children with ASD was compared to a propensity score-matched group of TD children (mean age = 13 years). The same comparison was carried out for a subgroup of nine children with ASD who were less trained in social cognition, according to clinician’s report. The ASD group performed overall worse in emotion recognition than the TD group, independently of emotion or gaze direction. However, for disgust expressions, eye tracking data revealed that TD children fixated relatively longer on the eyes of the stimulus face with a direct gaze as compared with averted gaze. In children with ASD we observed no such modulation of fixation behavior as a function of gaze direction. Overall, the present findings from ERPs and eye tracking confirm the hypothesis of an impaired sensitivity to gaze direction in children with ASD or elevated autistic traits, at least for specific emotions. Therefore, we conclude that multimodal investigations of the interaction between emotional processing and stimulus gaze direction are promising to understand the characteristics of individuals differing along the autism trait dimension.

Encoding of facial features by single neurons in the human amygdala and hippocampus

Faces are salient social stimuli that attract a stereotypical pattern of eye movement. The human amygdala and hippocampus are involved in various aspects of face processing; however, it remains unclear how they encode the content of fixations when viewing faces. To answer this question, we employed single-neuron recordings with simultaneous eye tracking when participants viewed natural face stimuli. We found a class of neurons in the human amygdala and hippocampus that encoded salient facial features such as the eyes and mouth. With a control experiment using non-face stimuli, we further showed that feature selectivity was specific to faces. We also found another population of neurons that differentiated saccades to the eyes vs. the mouth. Population decoding confirmed our results and further revealed the temporal dynamics of face feature coding. Interestingly, we found that the amygdala and hippocampus played different roles in encoding facial features. Lastly, we revealed two functional roles of feature-selective neurons: 1) they encoded the salient region for face recognition, and 2) they were related to perceived social trait judgments. Together, our results link eye movement with neural face processing and provide important mechanistic insights for human face perception.

Dynamic face processing impairments are associated with cognitive and positive psychotic symptoms across psychiatric disorders

Impairments in social cognition—including recognition of facial expressions—are increasingly recognised as a core deficit in schizophrenia. It remains unclear whether other aspects of face processing (such as identity recognition) are also impaired, and whether such deficits can be attributed to more general cognitive difficulties. Moreover, while the majority of past studies have used picture-based tasks to assess face recognition, literature suggests that video-based tasks elicit different neural activations and have greater ecological validity. This study aimed to characterise face processing using video-based stimuli in psychiatric inpatients with and without psychosis. Symptom correlates of face processing impairments were also examined. Eighty-six psychiatric inpatients and twenty healthy controls completed a series of tasks using video-based stimuli. These included two emotion recognition tasks, two non-emotional facial identity recognition tasks, and a non-face control task. Symptoms were assessed using the Positive and Negative Syndrome Scale. Schizophrenia and bipolar disorder groups were significantly impaired on the emotion-processing tasks and the non-face task compared to healthy controls and patients without psychosis. Patients with other forms of psychosis performed intermediately. Groups did not differ in non-emotional face processing. Positive symptoms of psychosis correlated directly with both emotion-processing performance and non-face discrimination across patients. We found that identity processing performance was inversely associated with cognition-related symptoms only. Findings suggest that deficits in emotion-processing reflect symptom pathology independent of diagnosis. Emotion-processing deficits in schizophrenia may be better accounted for by task-relevant factors—such as attention—that are not specific to emotion processing.

EEG frequency-tagging demonstrates increased left hemispheric involvement and crossmodal plasticity for face processing in congenitally deaf signers

In humans, face-processing relies on a network of brain regions predominantly in the right occipito-temporal cortex. We tested congenitally deaf (CD) signers and matched hearing controls (HC) to investigate the experience dependence of the cortical organization of face processing. Specifically, we used EEG frequency-tagging to evaluate: (1) Face-Object Categorization, (2) Emotional Facial-Expression Discrimination and (3) Individual Face Discrimination. The EEG was recorded to visual stimuli presented at a rate of 6 Hz, with oddball stimuli at a rate of 1.2 Hz. In all three experiments and in both groups, significant face discriminative responses were found. Face-Object categorization was associated to a relative increased involvement of the left hemisphere in CD individuals compared to HC individuals. A similar trend was observed for Emotional Facial-Expression discrimination but not for Individual Face Discrimination. Source reconstruction suggested a greater activation of the auditory cortices in the CD group for Individual Face Discrimination. These findings suggest that the experience dependence of the relative contribution of the two hemispheres as well as crossmodal plasticity vary with different aspects of face processing.

Guess who? Facial identity discrimination training improves face memory in typically developing children.

While vast individual differences in face recognition have been observed in adults, very little work has explored when these differences come online during development, their domain specificity, and their consistency across different aspects of face processing. These issues do not only have important theoretical implications for the cognitive and developmental psychological literatures, but may reveal critical windows of neuroplasticity for optimal remediation of face recognition impairments. Here, we describe the first formal remedial face training program that is suitable for children, modifying the popular game Guess Who. Eighty-one typical children Aged 4-11 years were randomly allocated to an experimental or active control training condition. Over 10 training sessions, experimental participants were required to discriminate between faces that differed in feature size or spacing across 10 levels of difficulty, whereas control participants continuously played the standard version of Guess Who within the same timeframe. Improvements in face memory but not face matching were observed in the experimental compared to the control group, but there were no gains on tests of object matching or memory. Face memory gains were maintained in a 1-month follow up, consistent across age, and larger for poorer perceivers. Thus, this study not only presents a promising means of improving face recognition skills in children, but also indicates a consistent period of plasticity that spans early childhood to preadolescence, implying early segregation of face versus object processing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

2288 Neural correlates of face processing in autism spectrum disorder: A quantitative meta-analysis of current literature and future directions

OBJECTIVES/SPECIFIC AIMS: Autism spectrum disorder (ASD) affects 1 in 68 people and includes restricted, repetitive behavior, and social communication deficits. Aspects of face processing (i.e., identity, emotion perception) are impaired in some with ASD. Neuroimaging studies have shown aberrant patterns of brain activation and connectivity of face processing regions. However, small sample sizes and inconsistent results have hindered clinical utility of these findings. The study aims to establish consistent patterns of brain responses to faces in ASD and provide directions for future research. METHODS/STUDY POPULATION: Neuroimaging studies were identified through a multi-database search according to PRISMA guidelines. In total, 23 studies were retained for a sample size of 383 healthy controls and 345 ASD. Peak coordinates were extracted for activation likelihood estimation (ALE) in GingerALE v2.3.6. Follow-up ALE analyses investigated directed Versus undirected gaze, static Versus dynamic, emotional Versus neutral, and familiar Versus unfamiliar faces. RESULTS/ANTICIPATED RESULTS: Faces produced bilateral activation of the fusiform gyrus (FG) in healthy controls (−42 −52 −20; 22 −74 −12, p<0.05, FDR) and left FG activation in ASD (−42 −54 −16, p<0.05, FDR). Activation in both groups was lateral to the mid-fusiform sulcus. Follow-up results pending. DISCUSSION/SIGNIFICANCE OF IMPACT: Reduced right FG activation to faces may inform biomarker or response to intervention studies. Mid-fusiform sulcus proved a reliable predictor of functional divides should be investigated on a subject-specific level.

Face Recognition is Shaped by the Use of Sign Language

Previous research has suggested that early deaf signers differ in face processing. Which aspects of face processing are changed and the role that sign language may have played in that change are however unclear. Here, we compared face categorization (human/non-human) and human face recognition performance in early profoundly deaf signers, hearing signers, and hearing non-signers. In the face categorization task, the three groups performed similarly in term of both response time and accuracy. However, in the face recognition task, signers (both deaf and hearing) were slower than hearing non-signers to accurately recognize faces, but had a higher accuracy rate. We conclude that sign language experience, but not deafness, drives a speed-accuracy trade-off in face recognition (but not face categorization). This suggests strategic differences in the processing of facial identity for individuals who use a sign language, regardless of their hearing status.

Face perception and learning in autism spectrum disorders.

Autism Spectrum Disorder (ASD) is characterized by impairment in social communication and restricted and repetitive interests. While not included in the diagnostic characterization, aspects of face processing and learning have shown disruptions at all stages of development in ASD, although the exact nature and extent of the impairment vary by age and level of functioning of the ASD sample as well as by task demands. In this review, we examine the nature of face attention, perception, and learning in individuals with ASD focusing on three broad age ranges (early development, middle childhood, and adolescence/adulthood). We propose that early delays in basic face processing contribute to the atypical trajectory of social communicative skills in individuals with ASD and contribute to poor social learning throughout development. Face learning is a life-long necessity, as the social world of individual only broadens with age, and thus addressing both the source of the impairment in ASD as well as the trajectory of ability throughout the lifespan, through targeted treatments, may serve to positively impact the lives of individuals who struggle with social information and understanding.

General and specific factors in the processing of faces

The ability to recognize faces varies considerably between individuals, but does performance co-vary for tests of different aspects of face processing? For 397 participants (of whom the majority were university students) we obtained scores on the Mooney Face Test, Glasgow Face Matching Test (GFMT), Cambridge Face Memory Test (CFMT) and Composite Face Test. Overall performance was significantly correlated for each pair of tests, and we suggest the term f for the factor underlying this pattern of positive correlations. However, there were large variations in the amount of variance shared by individual tests: The GFMT and CFMT are strongly related, whereas the GFMT and the Mooney test tap largely independent abilities. We do not replicate a frequently reported relationship between holistic processing (from the Composite test) and face recognition (from the CFMT)—indeed, holistic processing does not correlate with any of our tests. We report associations of performance with digit ratio and autism-spectrum quotient (AQ), and from our genome-wide association study we include a list of suggestive genetic associations with performance on the four face tests, as well as with f.

Face-space: A unifying concept in face recognition research.

The concept of a multidimensional psychological space, in which faces can be represented according to their perceived properties, is fundamental to the modern theorist in face processing. Yet the idea was not clearly expressed until 1991. The background that led to the development of face-space is explained, and its continuing influence on theories of face processing is discussed. Research that has explored the properties of the face-space and sought to understand caricature, including facial adaptation paradigms, is reviewed. Face-space as a theoretical framework for understanding the effect of ethnicity and the development of face recognition is evaluated. Finally, two applications of face-space in the forensic setting are discussed. From initially being presented as a model to explain distinctiveness, inversion, and the effect of ethnicity, face-space has become a central pillar in many aspects of face processing. It is currently being developed to help us understand adaptation effects with faces. While being in principle a simple concept, face-space has shaped, and continues to shape, our understanding of face perception.

The Influence of Averageness on Adults' Perceptions of Attractiveness: The Effect of Early Visual Deprivation.

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.

Too bad: Bias for angry faces in social anxiety interferes with identity processing

The recognition of faces across incidences is a complex function of the human brain and a crucial ability for communication and daily interactions. This first study on ERP correlates of emotional face learning in social anxiety disorder (SAD) investigates whether the known attentional bias for threatening faces leads to a corresponding memory bias. Therefore, 21 patients with SAD and 21 healthy controls (HCs) learned faces with emotional facial expressions (neutral, happy, and angry) and were later asked to recognize these out of novel identities all presented with a neutral facial expression. EEG was recorded throughout. Behaviorally, the faces' emotional expression modulated later recognition in terms of accuracy, response times, signal detection parameters and ratings of valence, but with better performance for happy than angry faces in HC as well as in SAD. In the learning phase, attention- and memory-associated event-related potentials (ERPs) P100, N170, P200, N250/EPN, and LPP indicated enhanced processing of angry faces, which was restricted to patients with SAD in N250/EPN and LPP. In the test phase, familiarity effects emerged in N250, FN400 and LPP. While N250 was affected by learned-angry faces, FN400 and LPP reflected image learning of neutral faces, which was restricted to SAD in LPP. We replicated the attentional bias to threatening faces, which was not restricted to early ERP components, but was prolonged to later stages of conscious processing, especially in SAD. In contrast to what had been expected, sustained hypervigilance to the emotional content seems to have impaired the processing of the facial identity, resulting in a happy face advantage at the behavioral level. This could be explained by prominent models assuming separate processing of facial emotion and identity. Hypervigilance in SAD might be a disadvantage in those studies focusing on other aspects of face processing than emotion.

Passively Improving Face Processing with LTP-like Visual Stimulation

Event Abstract Back to Event Passively Improving Face Processing with LTP-like Visual Stimulation Felipe Pegado1*, Bart Boets1 and Hans OpDeBeeck1 1 KU Leuven University, Belgium Humans can learn and remember complex visual patterns: different faces, objects, places and printed words. Neuroimaging studies have shown that learning about such visual objects is related to changes in specialized areas in high-level visual cortex. Animal studies have characterized learning and memory mechanisms at the cellular level by showing enhanced synaptic strength. Synaptic strength can be artificially enhanced by high-frequency neuronal stimulation (long-term potentiation [LTP]) and reduced by low-frequency stimulation (long-term depression [LTD]). However, the relation between the systems-level and the synaptic level has been largely neglected in the study of high-level visual learning. Recently, stimulation protocols have begun to be applied in humans, showing selective learning through non-invasive brain stimulation (e.g. TMS) and even through sensorial stimulation. For the first time, we translated this principle to high-level vision, passively manipulating face processing in humans. A face discrimination task was applied before and after passive stimulation protocols with faces stimuli (LTP-like vs LTD-like). The results show differential changes in performance, with the LTP-like group outperforming the LTD-like group, despite equivalent baseline performances. This outcome was replicated on each of three test blocks after stimulation and effects were even robust at the single-subject level. The present work represents a proof of principle that this bottom-up learning approach can be used to i) provide a new perspective on the neural mechanisms of high-level visual learning (e.g., face processing); ii) test neural plasticity of specific neural circuits in clinical populations (e.g., networks for face processing in autism) and iii) test the potential therapeutic value of targeted visual learning interventions (e.g., to improve particular aspects of face processing in autism), with the advantage of being non-invasive, easy to set-up and effortless. Keywords: autism, face processing, high-level vision, Translational research, LTP-like, passive learning Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Memory and Learning Citation: Pegado F, Boets B and OpDeBeeck H (2015). Passively Improving Face Processing with LTP-like Visual Stimulation. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00239 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Dr. Felipe Pegado, KU Leuven University, Leuven, Belgium, Felipe.FernandesPegado@ppw.kuleuven.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Felipe Pegado Bart Boets Hans OpDeBeeck Google Felipe Pegado Bart Boets Hans OpDeBeeck Google Scholar Felipe Pegado Bart Boets Hans OpDeBeeck PubMed Felipe Pegado Bart Boets Hans OpDeBeeck Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Holistic processing, contact, and the other-race effect in face recognition.

Face recognition, holistic processing, and processing of configural and featural facial information are known to be influenced by face race, with better performance for own- than other-race faces. However, whether these various other-race effects (OREs) arise from the same underlying mechanisms or from different processes remains unclear. The present study addressed this question by measuring the OREs in a set of face recognition tasks, and testing whether these OREs are correlated with each other. Participants performed different tasks probing (1) face recognition, (2) holistic processing, (3) processing of configural information, and (4) processing of featural information for both own- and other-race faces. Their contact with other-race people was also assessed with a questionnaire. The results show significant OREs in tasks testing face memory and processing of configural information, but not in tasks testing either holistic processing or processing of featural information. Importantly, there was no cross-task correlation between any of the measured OREs. Moreover, the level of other-race contact predicted only the OREs obtained in tasks testing face memory and processing of configural information. These results indicate that these various cross-race differences originate from different aspects of face processing, in contrary to the view that the ORE in face recognition is due to cross-race differences in terms of holistic processing.

Reverse engineering the face space: Discovering the critical features for face identification.

How do we identify people? What are the critical facial features that define an identity and determine whether two faces belong to the same person or different people? To answer these questions, we applied the face space framework, according to which faces are represented as points in a multidimensional feature space, such that face space distances are correlated with perceptual similarities between faces. In particular, we developed a novel method that allowed us to reveal the critical dimensions (i.e., critical features) of the face space. To that end, we constructed a concrete face space, which included 20 facial features of natural face images, and asked human observers to evaluate feature values (e.g., how thick are the lips). Next, we systematically and quantitatively changed facial features, and measured the perceptual effects of these manipulations. We found that critical features were those for which participants have high perceptual sensitivity (PS) for detecting differences across identities (e.g., which of two faces has thicker lips). Furthermore, these high PS features vary minimally across different views of the same identity, suggesting high PS features support face recognition across different images of the same face. The methods described here set an infrastructure for discovering the critical features of other face categories not studied here (e.g., Asians, familiar) as well as other aspects of face processing, such as attractiveness or trait inferences.

Implicit Manipulation of Face Processing Performance with LTP/LTD-like Visual Stimulation

Event Abstract Back to Event Implicit Manipulation of Face Processing Performance with LTP/LTD-like Visual Stimulation Felipe Pegado1*, Bart Boets1 and Hans Op De Beeck1 1 KU Leuven University, Belgium Humans can learn and remember complex visual patterns, such as a wide range of different faces, objects, places and printed words. Neuroimaging studies have shown that learning about such visual images is related to changes in specialized areas in high-level visual cortex. In addition, animal studies have characterized learning and memory mechanisms at the cellular level by showing enhanced synaptic strength. Importantly, synaptic strength can be artificially enhanced by high-frequency neuronal stimulation (long-term potentiation [LTP]) and also reduced by low-frequency stimulation (long-term depression [LTD]). Recently, frequency-dependent stimulation protocols have begun to be applied in humans, showing selective learning through non-invasive brain stimulation (e.g. TMS) and even through sensorial stimulation. In the present work, we translated this principle previously shown for elementary perception to a more complex and everyday-life relevant class of visual stimuli: human faces. A face discrimination task was applied to track performance on face processing, before and after 40 minutes of repetitive presentation of face stimuli at high and low frequencies (LTP-like vs LTD-like groups). The results shown differential changes in performance, with the LTP-like group outperforming the LTD-like group, despite equivalent baseline error rates. This outcome was replicated on each of three task blocks after stimulation and effects were even robust at the single-subject level. The present study represents a proof of principle that this bottom-up learning approach can be used to i) provide a new perspective on the neural mechanisms of high-level visual learning (e.g., face processing); ii) test neural plasticity of specific neural circuits in clinical populations (e.g., networks for face processing in autism) and iii) test the potential therapeutic value of targeted visual learning interventions (e.g., to improve particular aspects of face processing in autism), with the advantage of being non-invasive, easy to set-up and effortless. Keywords: face processing, LTP-like, Perceptual Learning, passive learning, Translational research, autism Conference: Belgian Brain Council 2014 MODULATING THE BRAIN: FACTS, FICTION, FUTURE, Ghent, Belgium, 4 Oct - 4 Oct, 2014. Presentation Type: Poster Presentation Topic: Basic Neuroscience Citation: Pegado F, Boets B and Op De Beeck H (2014). Implicit Manipulation of Face Processing Performance with LTP/LTD-like Visual Stimulation . Conference Abstract: Belgian Brain Council 2014 MODULATING THE BRAIN: FACTS, FICTION, FUTURE. doi: 10.3389/conf.fnhum.2014.214.00068 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 Jul 2014; Published Online: 16 Aug 2014. * Correspondence: Dr. Felipe Pegado, KU Leuven University, Leuven, Belgium, felipepegado@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Felipe Pegado Bart Boets Hans Op De Beeck Google Felipe Pegado Bart Boets Hans Op De Beeck Google Scholar Felipe Pegado Bart Boets Hans Op De Beeck PubMed Felipe Pegado Bart Boets Hans Op De Beeck Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

P 46. Featural and Configural processing of faces are dissociated in the dorsolateral prefrontal cortex: A TMS study

Facial recognition relies on distinct and parallel types of processing: featural processing focuses on the individual components of a face (e.g., the shape or the size of the eyes), whereas configural (or “relational”) processing considers the spatial interrelationships among the single facial components (e.g., distance of the mouth from the nose). Previous neuroimaging evidence has suggested that featural and configural processes may rely on different brain circuits. By using rTMS, here we show for the first time a double dissociation in dorsolateral prefrontal cortex for different aspects of face processing. Twelve participants were asked to perform a same-different judgment task (“Jane faces” task, Mondloch et al., 2002, Perception 31:553–66) on two shortly consecutive presented faces. Two sets of stimuli (faces differing either for featural or configural aspects) were run separately to allow time for each style of processing to emerge. Triple-pulse TMS was delivered between 100 and 150 ms after the onset of the second face stimulus over the left middle frontal gyrus, the right middle frontal gyrus, or the vertex, in addition to a condition where no TMS was administered. TMS over the left middle frontal gyrus selectively disrupted featural processing, whereas TMS over the right frontal gyrus selectively interfered with configural processing of faces. By establishing a causal link between activation in left and right prefrontal areas and different modes of face processing, our data extend previous neuroimaging evidence and may have important implications in the study of face-processing deficits, such as those manifested in prosopagnosia and autistic spectrum disorders.

It's not only in the eyes: Nonlinear relationship between face orientation and N170 amplitude irrespective of eye presence

We have investigated the interplay between face orientation, eye presence, and N170 amplitude by recording Event Related Potentials. To clarify previous reports of nonlinearity in N170 amplitude changes along rotation angle changes, we adopted Itier et al.'s model (Itier et al., 2007) which links N170 face inversion effects with the presence of eyes. Comparison of N170 amplitude and latency for five stimulus categories (Faces-with-eyes, Faces-without-eyes, Eyes, Cars-with-lights, Cars-without-lights) in five different rotations (0, 45, 90, 135, 180) resulted in mixed conclusions. The main findings of this study are as follows: (1) a strong nonlinear relationship between N170 and angle of rotation that is specific to faces, distinguishing face from car category even when no significant differences were observed between these categories for upright and inverted orientations; and (2) the nonlinear relationship between N170 and angle of rotation does not depend on eye presence. We also propose an alternative model according to which N170 amplitude consists of two related aspects of face processing: (A) incompatibility (relative distance of the stimulus pattern from experience-based hypothetical prototype) and (B) integration (degree to which stimulus is integrated into holistic representation), with the former affecting the latter. Moreover, we suggest two possible neural events underlying these two aspects of face processing: neural population size activated by the stimulus, and synchronization within this population.

Processing of featural and configural aspects of faces is lateralized in dorsolateral prefrontal cortex: A TMS study

Facial recognition relies on distinct and parallel types of processing: featural processing focuses on the individual components of a face (e.g., the shape or the size of the eyes), whereas configural (or "relational") processing considers the spatial interrelationships among the single facial components (e.g., distance of the mouth from the nose). Previous neuroimaging evidence has suggested that featural and configural processes may rely on different brain circuits. By using rTMS, here we show for the first time a double dissociation in dorsolateral prefrontal cortex for different aspects of face processing: in particular, TMS over the left middle frontal gyrus (BA8) selectively disrupted featural processing, whereas TMS over the right inferior frontal gyrus (BA44) selectively interfered with configural processing of faces. By establishing a causal link between activation in left and right prefrontal areas and different modes of face processing, our data extend previous neuroimaging evidence and may have important implications in the study of face-processing deficits, such as those manifested in prosopagnosia and autistic spectrum disorders.