Face-selective Responses Research Articles

Rapid categorization of natural face images in the infant right hemisphere.

Human performance at categorizing natural visual images surpasses automatic algorithms, but how and when this function arises and develops remain unanswered. We recorded scalp electrical brain activity in 4-6 months infants viewing images of objects in their natural background at a rapid rate of 6 images/second (6 Hz). Widely variable face images appearing every 5 stimuli generate an electrophysiological response over the right hemisphere exactly at 1.2 Hz (6 Hz/5). This face-selective response is absent for phase-scrambled images and therefore not due to low-level information. These findings indicate that right lateralized face-selective processes emerge well before reading acquisition in the infant brain, which can perform figure-ground segregation and generalize face-selective responses across changes in size, viewpoint, illumination as well as expression, age and gender. These observations made with a highly sensitive and objective approach open an avenue for clarifying the developmental course of natural image categorization in the human brain.

Beyond the core face-processing network: intracerebral stimulation of a face-selective area in the right anterior fusiform gyrus elicits transient prosopagnosia

Event Abstract Back to Event Beyond the core face-processing network: intracerebral stimulation of a face-selective area in the right anterior fusiform gyrus elicits transient prosopagnosia Jacques Jonas1* and Bruno Rossion1 1 Université Catholique de Louvain, Belgium According to neuropsychological evidence, a distributed network of face-selective regions of the ventral visual pathway supports face recognition. However, fMRI studies have generally confined to the posterior face-selective areas, i.e., the occipital face area (OFA) and the fusiform face area (FFA). There is recent evidence that intracranial electrical stimulation of the OFA and FFA elicits face recognition impairments. Here we were able to test for face recognition in a patient implanted with depth electrodes in the anterior temporal cortex. Electrically stimulating the right anterior fusiform gyrus, in a region located anteriorly to the FFA, induced a transient inability to recognize familiar faces (Fig. 1, stimulation of electrodes F3, F4, F4 and F6; movies available). This region was shown face-selective as revealed by intracerebral face-selective event-related potentials and gamma band activity recorded at these critical electrodes. However, no fMRI face-selective responses were found in this region due to severe BOLD signal drop-out caused by the ear canal artifacts (see raw EPI slices, Fig. 2). These results point to a causal role in face recognition of the right anterior fusiform gyrus and more generally of face-selective areas located beyond the “core” face processing network in the ventral temporal cortex. It also illustrates the diagnostic value of intracerebral recordings and stimulation in understanding the neural basis of face recognition and visual recognition in general. Figure 1 Figure 2 Keywords: Intracerebral recordings, electrical brain stimulation, face perception, anterior fusiform gyrus, Fusiform face area Conference: 11th National Congress of the Belgian Society for Neuroscience, Mons, Belgium, 22 May - 22 May, 2015. Presentation Type: Oral or Poster presentation Topic: Neuroscience Citation: Jonas J and Rossion B (2015). Beyond the core face-processing network: intracerebral stimulation of a face-selective area in the right anterior fusiform gyrus elicits transient prosopagnosia. Front. Neurosci. Conference Abstract: 11th National Congress of the Belgian Society for Neuroscience. doi: 10.3389/conf.fnins.2015.89.00087 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: 08 May 2015; Published Online: 14 May 2015. * Correspondence: Dr. Jacques Jonas, Université Catholique de Louvain, Louvain-la-Neuve, Please Select, 1348, Belgium, jac.jonas@gmail.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 Jacques Jonas Bruno Rossion Google Jacques Jonas Bruno Rossion Google Scholar Jacques Jonas Bruno Rossion PubMed Jacques Jonas Bruno Rossion 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.

Rapid definition of objective electrophysiological face-selective responses by means of fast periodic visual stimulation

Rapid definition of objective electrophysiological face-selective responses by means of fast periodic visual stimulation

Removing the right inferior occipital gyrus does not disrupt face-selective responses in human ventral temporal cortex: Evidence against a strict hierarchical model of face perception

Removing the right inferior occipital gyrus does not disrupt face-selective responses in human ventral temporal cortex: Evidence against a strict hierarchical model of face perception

Face, eye, and body selective responses in fusiform gyrus and adjacent cortex: an intracranial EEG study.

Functional MRI (fMRI) studies have investigated the degree to which processing of whole faces, face-parts, and bodies are differentially localized within the fusiform gyrus and adjacent ventral occipitotemporal cortex. While some studies have emphasized the spatial differentiation of processing into discrete areas, others have emphasized the overlap of processing and the importance of distributed patterns of activity. Intracranial EEG (iEEG) recorded from subdural electrodes provides excellent temporal and spatial resolution of local neural activity, and thus provides an alternative method to fMRI for studying differences and commonalities in face and body processing. In this study we recorded iEEG from 12 patients while they viewed images of novel faces, isolated eyes, headless bodies, and flowers. Event-related potential analysis identified 69 occipitotemporal sites at which there was a face-, eye-, or body-selective response when contrasted to flowers. However, when comparing faces, eyes, and bodies to each other at these sites, we identified only 3 face-specific, 13 eye-specific, and 1 body-specific electrodes. Thus, at the majority of sites, faces, eyes, and bodies evoked similar responses. However, we identified ten locations at which the amplitude of the responses spatially varied across adjacent electrodes, indicating that the configuration of current sources and sinks were different for faces, eyes, and bodies. Our results also demonstrate that eye-sensitive regions are more abundant and more purely selective than face- or body-sensitive regions, particularly in lateral occipitotemporal cortex.

Emotional Processing of Personally Familiar Faces in the Vegetative State

BackgroundThe Vegetative State (VS) is a severe disorder of consciousness in which patients are awake but display no signs of awareness. Yet, recent functional magnetic resonance imaging (fMRI) studies have demonstrated evidence for covert awareness in VS patients by recording specific brain activations during a cognitive task. However, the possible existence of incommunicable subjective emotional experiences in VS patients remains largely unexplored. This study aimed to probe the question of whether VS patients retain a brain ability to selectively process external stimuli according to their emotional value and look for evidence of covert emotional awareness in patients.Methods and FindingsIn order to explore these questions we employed the emotive impact of observing personally familiar faces, known to provoke specific perceptual as well as emotional brain activations. Four VS patients and thirteen healthy controls first underwent an fMRI scan while viewing pictures of non-familiar faces, personally familiar faces and pictures of themselves. In a subsequent imagery task participants were asked to actively imagine one of their parent's faces. Analyses focused on face and familiarity selective regional brain activations and inter-regional functional connectivity. Similar to controls, all patients displayed face selective brain responses with further limbic and cortical activations elicited by familiar faces. In patients as well as controls, Connectivity was observed between emotional, visual and face specific areas, suggesting aware emotional perception. This connectivity was strongest in the two patients who later recovered. Notably, these two patients also displayed selective amygdala activation during familiar face imagery, with one further exhibiting face selective activations, indistinguishable from healthy controls.ConclusionsTaken together, these results show that selective emotional processing can be elicited in VS patients both by external emotionally salient stimuli and by internal cognitive processes, suggesting the ability for covert emotional awareness of self and the environment in VS patients.

Functional organization and visual representations of human ventral lateral prefrontal cortex

Recent neuroimaging studies in both human and non-human primates have identified face selective activation in the ventral lateral prefrontal cortex (VLPFC) even in the absence of working memory (WM) demands. Further, research has suggested that this face-selective response is largely driven by the presence of the eyes. However, the nature and origin of visual category responses in the VLPFC remain unclear. In a broader sense, how do these findings relate to our current understandings of lateral prefrontal cortex? What do these findings tell us about the underlying function and organization principles of the VLPFC? What is the future direction for investigating visual representations in this cortex? This review focuses on the function, topography, and circuitry of the VLPFC to enhance our understanding of the evolution and development of this cortex.

Face Selectivity Properties of Monkey Temporal Cortical Neurons Predicted by Computer Vision

In this issue of Neuron, Ohayon etal. (2012) utilize fMRI-guided single-cell recordings to demonstrate the importance of contrast polarity features for face-selective responses in macaque temporal cortex, as predicted by a computer vision face detection algorithm.

A critical review of the development of face recognition: Experience is less important than previously believed

Historically, it has been argued that face individuation 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 individuation (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 individuation (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 individuation 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.

Defining face perception areas in the human brain: A large-scale factorial fMRI face localizer analysis

A number of human brain areas showing a larger response to faces than to objects from different categories, or to scrambled faces, have been identified in neuroimaging studies. Depending on the statistical criteria used, the set of areas can be overextended or minimized, both at the local (size of areas) and global (number of areas) levels. Here we analyzed a whole-brain factorial functional localizer obtained in a large sample of right-handed participants (40). Faces (F), objects (O; cars) and their phase-scrambled counterparts (SF, SO) were presented in a block design during a one-back task that was well matched for difficulty across conditions. A conjunction contrast at the group level {(F–SF) and (F–O)} identified six clusters: in the pulvinar, inferior occipital gyrus (so-called OFA), middle fusiform gyrus (so-called FFA), posterior superior temporal sulcus, amygdala, and anterior infero-temporal cortex, which were all strongly right lateralized. While the FFA showed the largest difference between faces and cars, it also showed the least face-selective response, responding more to cars than scrambled cars. Moreover, the FFA’s larger response to scrambled faces than scrambled cars suggests that its face-sensitivity is partly due to low-level visual cues. In contrast, the pattern of activation in the OFA points to a higher degree of face-selectivity. A BOLD latency mapping analysis suggests that face-sensitivity emerges first in the right FFA, as compared to all other areas. Individual brain analyses support these observations, but also highlight the large amount of interindividual variability in terms of number, height, extent and localization of the areas responding preferentially to faces in the human ventral occipito-temporal cortex. This observation emphasizes the need to rely on different statistical thresholds across the whole brain and across individuals to define these areas, but also raises some concerns regarding any objective labeling of these areas to make them correspond across individual brains. This large-scale analysis helps understanding the set of face-sensitive areas in the human brain, and encourages in-depth single participant analyses in which the whole set of areas is considered in each individual brain.

Single-Unit Responses Selective for Whole Faces in the Human Amygdala

The human amygdala is critical for social cognition from faces, as borne out by impairments in recognizing facial emotion following amygdala lesions [1] and differential activation of the amygdala by faces [2-5]. Single-unit recordings in the primate amygdala have documented responses selective for faces, their identity, or emotional expression [6, 7], yet how the amygdala represents face information remains unknown. Does it encode specific features of faces that are particularly critical for recognizing emotions (such as the eyes), or does it encode the whole face, a level of representation that might be the proximal substrate for subsequent social cognition? We investigated this question by recording from over 200 single neurons in the amygdalae of seven neurosurgical patients with implanted depth electrodes [8]. We found that approximately half of all neurons responded to faces or parts of faces. Approximately 20% of all neurons responded selectively only to the whole face. Although responding most to whole faces, these neurons paradoxically responded more when only a small part of the face was shown compared to when almost the entire face was shown. We suggest that the human amygdala plays a predominant role in representing global information about faces, possibly achieved through inhibition between individual facial features.

Face-likeness and image variability drive responses in human face-selective ventral regions.

The human ventral visual stream contains regions that respond selectively to faces over objects. However, it is unknown whether responses in these regions correlate with how face-like stimuli appear. Here, we use parameterized face silhouettes to manipulate the perceived face-likeness of stimuli and measure responses in face- and object-selective ventral regions with high-resolution fMRI. We first use "concentric hyper-sphere" (CH) sampling to define face silhouettes at different distances from the prototype face. Observers rate the stimuli as progressively more face-like the closer they are to the prototype face. Paradoxically, responses in both face- and object-selective regions decrease as face-likeness ratings increase. Because CH sampling produces blocks of stimuli whose variability is negatively correlated with face-likeness, this effect may be driven by more adaptation during high face-likeness (low-variability) blocks than during low face-likeness (high-variability) blocks. We tested this hypothesis by measuring responses to matched-variability (MV) blocks of stimuli with similar face-likeness ratings as with CH sampling. Critically, under MV sampling, we find a face-specific effect: responses in face-selective regions gradually increase with perceived face-likeness, but responses in object-selective regions are unchanged. Our studies provide novel evidence that face-selective responses correlate with the perceived face-likeness of stimuli, but this effect is revealed only when image variability is controlled across conditions. Finally, our data show that variability is a powerful factor that drives responses across the ventral stream. This indicates that controlling variability across conditions should be a critical tool in future neuroimaging studies of face and object representation.

Fusiform gyrus face selectivity relates to individual differences in facial recognition ability.

Regions of the occipital and temporal lobes, including a region in the fusiform gyrus (FG), have been proposed to constitute a "core" visual representation system for faces, in part because they show face selectivity and face repetition suppression. But recent fMRI studies of developmental prosopagnosics (DPs) raise questions about whether these measures relate to face processing skills. Although DPs manifest deficient face processing, most studies to date have not shown unequivocal reductions of functional responses in the proposed core regions. We scanned 15 DPs and 15 non-DP control participants with fMRI while employing factor analysis to derive behavioral components related to face identification or other processes. Repetition suppression specific to facial identities in FG or to expression in FG and STS did not show compelling relationships with face identification ability. However, we identified robust relationships between face selectivity and face identification ability in FG across our sample for several convergent measures, including voxel-wise statistical parametric mapping, peak face selectivity in individually defined "fusiform face areas" (FFAs), and anatomical extents (cluster sizes) of those FFAs. None of these measures showed associations with behavioral expression or object recognition ability. As a group, DPs had reduced face-selective responses in bilateral FFA when compared with non-DPs. Individual DPs were also more likely than non-DPs to lack expected face-selective activity in core regions. These findings associate individual differences in face processing ability with selectivity in core face processing regions. This confirms that face selectivity can provide a valid marker for neural mechanisms that contribute to face identification ability.

Modulation of face processing by emotional expression during intracranial recordings in right fusiform cortex and amygdala

Event Abstract Back to Event Modulation of face processing by emotional expression during intracranial recordings in right fusiform cortex and amygdala Gilles Pourtois1* and Patrik Vuilleumier2 1 Dept. of Psychology, Ghent University, Belgium 2 Neurology & Imaging of Cognition, Center of Neuroscience, University of Geneva, Switzerland Intracranial Local Field Potentials (iLFPs) were recorded from several object-selective cortical areas in a patient prior to brain surgery, including a right fusiform region with face-sensitive activity, and a more medial location in posterior parahippocampal gyrus with house-selective activity. Several experiments were conducted to determine the temporal dynamics of perceptual and emotional effects on face-specific responses in the right fusiform. Our findings showed an early negative deflection (N200) that primarily reflected category-selective perceptual encoding of facial information, whereas higher-order effects of face individuation and emotional expression produced selective modulations in the same face-specific region during a later time-period (from 200 up to 1000ms post-onset). These results shed new lights on the time-course of face recognition mechanisms in human visual cortex, and reveal anatomically overlapping, but temporally distinct influences of identity or emotional factors on face processing in right fusiform gyrus, which presumably reflect top-down feedback effects from distant brain areas, including the amygdala. This conjecture was verified by recording iLFPs in a second patient implanted with deep electrodes in the left lateral amygdala. Results disclosed an early emotional effect in the amygdala arising prior to, and independent of, attentional modulation. Altogether, these results suggest that the amygdala is involved in the early visual processing of emotional expression, while face-selective responses within the anterior fusiform gyrus are gated by emotional expression during a later time interval. Keywords: iLFPs, neural activity Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Symposium: Oral Presentation Topic: Symposium 7: From single neuron responses to neuronal population oscillations during vision and memory: new insights from human intracranial recordings Citation: Pourtois G and Vuilleumier P (2011). Modulation of face processing by emotional expression during intracranial recordings in right fusiform cortex and amygdala. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00513 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: 09 Nov 2011; Published Online: 28 Nov 2011. * Correspondence: Dr. Gilles Pourtois, Dept. of Psychology, Ghent University, Ghent, Belgium, gilles.pourtois@ugent.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 Gilles Pourtois Patrik Vuilleumier Google Gilles Pourtois Patrik Vuilleumier Google Scholar Gilles Pourtois Patrik Vuilleumier PubMed Gilles Pourtois Patrik Vuilleumier 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.

Neural responses in the occipital cortex to unrecognizable faces

Objective Event-related potentials (ERPs) were recorded to examine neural responses to face stimuli in a masking paradigm. Methods Images of faces (neutral or fearful) and objects were presented in subthreshold, threshold, and suprathreshold conditions (exposure durations of approximately 20, 30 and 300 ms, respectively), followed by a 1000-ms pattern mask. We recorded ERP responses at Oz, T5, T6, Cz and Pz. The effects of physical stimulus features were examined by inverted stimuli. Results The occipital N1 amplitude (approximately 160 ms) was significantly smaller in response to faces than objects when presented at a subthreshold duration. In contrast, the occipitotemporal N170 amplitude was significantly greater in the threshold and suprathreshold conditions compared with the subthreshold condition for faces, but not for objects. The P1 amplitude (approximately 120 ms) elicited by upright faces in the subthreshold condition was significantly larger than for inverted faces. Conclusions P1 and N1 components at Oz were sensitive to subthreshold faces, which suggests the presence of fast face-specific process(es) prior to face-encoding. The N170 reflects the robustness of the face selective response in the occipitotemporal area. Significance Even when presented for a subthreshold duration, faces were processed differently to images of objects at an early stage of visual processing.

What Body Parts Reveal about the Organization of the Brain

In this issue of Neuron, Orlov etal. show that the human occipitotemporal cortex contains regions responding preferentially to body part categories, such as upper limbs (hand, elbow), torsos, or lower faces (mouth, chin). This organization may reflect differences in the connectivity of these regions with other brain regions, to support the efficient processing of the different types of information different body parts provide.

The effects of parts, wholes, and familiarity on face-selective responses in MEG

Although face perception is commonly thought to rely on holistic, rather than part-based, processing, there is some evidence for part-based representations in the face processing stream. Previously (VSS 2007), we have probed holistic and part-based processing with faces manipulated in stereoscopic depth to appear either behind or in front of a set of stripes (Nakayama et al., 1989), which we have demonstrated behaviorally are perceived holistically or in terms of their constituent parts, respectively. Using these stimuli in functional magnetic resonance imaging (fMRI), we showed that “face-selective” regions respond equally to face parts and wholes. Within the right fusiform gyrus, we further found an interaction of processing and familiarity, with greater adaptation for the holistic relative to part-based condition for familiar but not unfamiliar faces. Here we extend this work by investigating the time course of these processing and familiarity effects using magnetoencephalography (MEG). We examined “face-selective” (Face [[gt]] House) components in occipitotemporal sensors at early (∼170–200 ms) and later (∼250–450 ms) latency ranges. While both M170 and “M400” components showed significantly larger responses for familiar versus unfamiliar faces, neither exhibited a main effect of holistic versus part-based processing, as indexed by depth. These data affirm the existence of “face-selective” part-based representations, and additionally demonstrate that such representations are present from relatively early stages of face processing. However, the interaction of familiarity and depth only reached significance in the later M400 latency range, with a larger response to the holistic condition for familiar but not unfamiliar faces. Likewise, behavioral recognition performance was significantly correlated with the M400, but not the M170, and only in the holistic condition. Together, these results suggest that, while face parts are represented from the early stages of processing indexed by the M170 response, modulatory effects of familiarity seen with fMRI occur later in the face processing stream.

Stronger face-selective responses to typical versus distinctive faces when stimulus variability is controlled

Stronger face-selective responses to typical versus distinctive faces when stimulus variability is controlled

Event‐related potential and functional MRI measures of face‐selectivity are highly correlated: A simultaneous ERP‐fMRI investigation

A face-selective neural signal is reliably found in humans with functional MRI and event-related potential (ERP) measures, which provide complementary information about the spatial and temporal properties of the neural response. However, because most neuroimaging studies so far have studied ERP and fMRI face-selective markers separately, the relationship between them is still unknown. Here we simultaneously recorded fMRI and ERP responses to faces and chairs to examine the correlations across subjects between the magnitudes of fMRI and ERP face-selectivity measures. Findings show that the face-selective responses in the temporal lobe (i.e., fusiform gyrus--FFA) and superior temporal sulcus (fSTS), but not the face-selective response in the occipital cortex (OFA), were highly correlated with the face-selective N170 component. In contrast, the OFA was correlated with earlier ERPs at about 110 ms after stimulus-onset. Importantly, these correlations reveal a temporal dissociation between the face-selective area in the occipital lobe and face-selective areas in the temporal lobe. Despite the very different time-scale of the fMRI and EEG signals, our data show that a correlation analysis across subjects may be informative with respect to the latency in which different brain regions process information.

Differential development of selectivity for faces and bodies in the fusiform gyrus

Viewing faces or bodies activates category-selective areas of visual cortex, including the fusiform face area (FFA), fusiform body area (FBA), and extrastriate body area (EBA). Here, using fMRI, we investigate the development of these areas, focusing on the right FFA and FBA. Despite the overlap of functionally defined FFA and FBA (54%-75% overlap), we found that these regions developed along different trajectories. With age (7-32 years old), the FFA gradually increased in size and selectivity, and was significantly larger and more face-selective in adults than children. By contrast, the size and selectivity of the FBA did not correlate with age, and were equivalent in children and adults. Whereas in adults the FFA and FBA were comparable in size, in children the FBA was on average 70% larger than the FFA. These findings suggest that, in children, the fusiform gyrus is predominantly selective for bodies, with commensurate face-selective responses apparent later in development. Moreover, differences in the development of the FFA and FBA indicate that overlapping functional brain areas, supported by the same anatomical structure, can develop along different trajectories.