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Isabel Gauthier - One of the best experts on this subject based on the ideXlab platform.
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Thickness of Deep Layers in the Fusiform Face Area Predicts Face Recognition.
Journal of cognitive neuroscience, 2020Co-Authors: Rankin W. Mcgugin, Allen T. Newton, Benjamin J. Tamber-rosenau, Andrew J. Tomarken, Isabel GauthierAbstract:People with superior Face recognition have relatively thin cortex in Face-selective brain Areas, whereas those with superior vehicle recognition have relatively thick cortex in the same Areas. We s...
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Thickness of deep layers in the Fusiform Face Area predicts Face recognition
2019Co-Authors: Rankin W. Mcgugin, Allen T. Newton, Benjamin J. Tamber-rosenau, Andrew J. Tomarken, Isabel GauthierAbstract:Abstract People with superior Face recognition have relatively thin cortex in Face-selective brain Areas, while those with superior vehicle recognition have relatively thick cortex in the same Areas. We suggest that these opposite correlations reflect distinct mechanisms influencing cortical thickness (CT) for abilities acquired at different points in development. We explore a new prediction regarding the specificity of these effects through the depth of the cortex: that Face recognition selectively and negatively correlates with thickness of the deepest laminar subdivision in Face-selective Areas. With ultra-high resolution MRI at 7T, we estimated the thickness of three laminar subdivisions, which we term MR layers, in the right Fusiform Face Area (rFFA) in 14 adult male humans. Face recognition was negatively associated with the thickness of deep MR layers, while vehicle recognition was positively related to the thickness of all layers. Regression model comparisons provided overwhelming support for a model specifying that the magnitude of the association between Face recognition and CT differs across MR layers (deep vs. superficial/middle) while the magnitude of the association between vehicle recognition and CT is invariant across layers. The total CT of rFFA accounted for 69% of the variance in Face recognition, and thickness of the deep layer alone accounted for 84% of this variance. Our findings demonstrate the functional validity of MR laminar estimates in FFA. Studying the structural basis of individual differences for multiple abilities in the same cortical Area can reveal effects of distinct mechanisms that are not apparent when studying average variation or development. Significance Statement Face and object recognition vary in the normal population and are only modestly related to each other. The recognition of Faces and vehicles are both positively related to neural responses in the Fusiform Face Area (FFA), but show different relations to the cortical thickness of FFA. Here, we use very high-resolution MRI, and find that Face recognition ability (a skill acquired early in life) is negatively correlated with thickness of FFA’s deepest MR-defined layers, whereas recognition of vehicles (a skill acquired later in life) is positively related to thickness at of all cortical layers. Our methods can be used in the future to characterize sources of variability in human abilities and relate them to distinct mechanisms of neural plasticity.
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High-resolution Functional Magnetic Resonance Imaging Reveals Configural Processing of Cars in Right Anterior Fusiform Face Area of Car Experts.
Journal of cognitive neuroscience, 2018Co-Authors: David Ross, Benjamin J. Tamber-rosenau, Jiedong Zhang, Thomas J. Palmeri, Isabel GauthierAbstract:Visual object expertise correlates with neural selectivity in the Fusiform Face Area (FFA). Although behavioral studies suggest that visual expertise is associated with increased use of holistic and configural information, little is known about the nature of the supporting neural representations. Using high-resolution 7-T functional magnetic resonance imaging, we recorded the multivoxel activation patterns elicited by whole cars, configurally disrupted cars, and car parts in individuals with a wide range of car expertise. A probabilistic support vector machine classifier was trained to differentiate activation patterns elicited by whole car images from activation patterns elicited by misconfigured car images. The classifier was then used to classify new combined activation patterns that were created by averaging activation patterns elicited by individually presented top and bottom car parts. In line with the idea that the configuration of parts is critical to expert visual perception, car expertise was negatively associated with the probability of a combined activation pattern being classified as a whole car in the right anterior FFA, a region critical to vision for categories of expertise. Thus, just as found for Faces in normal observers, the neural representation of cars in right anterior FFA is more holistic for car experts than car novices, consistent with common mechanisms of neural selectivity for Faces and other objects of expertise in this Area.
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Does visual subordinate-level categorisation engage the functionally defined Fusiform Face Area?
2018Co-Authors: Isabel Gauthier, Pawel Skudlarski, Michael J. Tarr, Jill Moylan, Adam W. Anderson, John C GoreAbstract:Functional magnetic resonance imaging was used to compare brain activation associated with basic-level (e.g. bird) and subordinate-level (e.g. eagle) processing for both visual and semantic judgements. We localised the putative Face Area for 11 subjects, who also performed visual matching judgements for pictures and aurally presented words. The middle Fusiform and occipital gyri were recruited for subordinate minus basic visual judgements, reflecting additional perceptual processing. When the Face Area was localised individually for each subject, analyses in the middle Fusiform gyri revealed that subordinate-level processing activated the individuals Face Area. We propose that what is unique about the way Faces engage this region is the focal spatial distribution of the activation rather than the recruitment of the Face per se. Eight subjects also performed semantic judgements on aurally presented basic- and subordinate-level words. The parahippocampal gyri were more activated for subordinate-level than basic-level semantic judgements. Finally, the left posterior inferior temporal gyrus was activated for subordinate-level judgements, both visual and semantic, as well as during passive viewing of Faces.
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cortical thickness in Fusiform Face Area predicts Face and object recognition performance
Journal of Cognitive Neuroscience, 2016Co-Authors: Rankin W. Mcgugin, Ana Van Gulick, Isabel GauthierAbstract:The Fusiform Face Area FFA is defined by its selectivity for Faces. Several studies have shown that the response of FFA to nonFace objects can predict behavioral performance for these objects. However, one possible account is that experts pay more attention to objects in their domain of expertise, driving signals up. Here, we show an effect of expertise with nonFace objects in FFA that cannot be explained by differential attention to objects of expertise. We explore the relationship between cortical thickness of FFA and Face and object recognition using the Cambridge Face Memory Test and Vanderbilt Expertise Test, respectively. We measured cortical thickness in functionally defined regions in a group of men who evidenced functional expertise effects for cars in FFA. Performance with Faces and objects together accounted for approximately 40% of the variance in cortical thickness of several FFA patches. Whereas participants with a thicker FFA cortex performed better with vehicles, those with a thinner FFA cortex performed better with Faces and living objects. The results point to a domain-general role of FFA in object perception and reveal an interesting double dissociation that does not contrast Faces and objects but rather living and nonliving objects.
Nancy Kanwisher - One of the best experts on this subject based on the ideXlab platform.
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pre stimulus pattern of activity in the Fusiform Face Area predicts Face percepts during binocular rivalry
Neuropsychologia, 2012Co-Authors: Pojang Hsieh, Jaron T Colas, Nancy KanwisherAbstract:Visual input is ambiguous, yet conscious experience is unambiguous. In binocular rivalry the two eyes receive conflicting images, but only one of them is consciously perceived at a time. Here we search for the neural sites of the competitive interactions underlying this phenomenon by testing whether neural pattern activity occurring before stimulus presentation can predict the initial dominant percept in binocular rivalry and, if so, where in the brain such predictive activity is found. Subjects were scanned while viewing an image of a Face in one eye and an image of a house in the other eye with anaglyph glasses. The rivalrous stimulus was presented briefly for each trial, and the subject indicated which of the two images he or she preferentially perceived. Our results show that BOLD fMRI multivariate pattern activity in the Fusiform Face Area (FFA) before the stimulus is presented predicts which of the two images will be dominant, suggesting that higher extrastriate Areas, such as the FFA, are not only correlated with, but may also be involved in determining the initial dominant percept in binocular rivalry. Furthermore, by examining pattern activity before and after trial onset, we found that pre-trial activity in the FFA for the rivalrous Face trials is no more similar to the post-trial activity for the non-rivalrous Face trials than to that for the non-rivalrous house trials, indicating a dissociation between neural pattern information, which predicts a given state of awareness, and mean responses, which reflect the state of awareness ultimately achieved.
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the Fusiform Face Area a cortical region specialized for the perception of Faces
Philosophical Transactions of the Royal Society B, 2006Co-Authors: Nancy Kanwisher, Galit YovelAbstract:Faces are among the most important visual stimuli we perceive, informing us not only about a person’s identity, but also about their mood, sex, age and direction of gaze. The ability to extract this information within a fraction of a second of viewing a Face is important for normal social interactions and has probably played a critical role in the survival of our primate ancestors. Considerable evidence from behavioural, neuropsychological and neurophysiological investigations supports the hypothesis that humans have specialized cognitive and neural mechanisms dedicated to the perception of Faces (the Face-specificity hypothesis). Here, we review the literature on a region of the human brain that appears to play a key role in Face perception, known as the Fusiform Face Area (FFA). Section 1 outlines the theoretical background for much of this work. The Face-specificity hypothesis falls squarely on one side of a longstanding debate in the fields of cognitive science and cognitive neuroscience concerning the extent to which the mind/brain is composed of: (i) special-purpose (‘domain-specific’) mechanisms, each dedicated to processing a specific kind of information (e.g. Faces, according to the Face-specificity hypothesis), versus (ii) general-purpose (‘domain-general’) mechanisms, each capable of operating on any kind of information. Face perception has long served both as one of the prime candidates of a domain-specific process and as a key target for attack by proponents of domain-general theories of brain and mind. Section 2 briefly reviews the prior literature on Face perception from behaviour and neurophysiology. This work supports the Face-specificity hypothesis and argues against its domain-general alternatives (the individuation hypothesis, the expertise hypothesis and others). Section 3 outlines the more recent evidence on this debate from brain imaging, focusing particularly on the FFA. We review the evidence that the FFA is selectively engaged in Face perception, by addressing (and rebutting) five of the most widely discussed alternatives to this hypothesis. In §4, we consider recent findings that are beginning to provide clues into the computations conducted in the FFA and the nature of the representations the FFA extracts from Faces. We argue that the FFA is engaged both in detecting Faces and in extracting the necessary perceptual information to recognize them, and that the properties of the FFA mirror previously identified behavioural signatures of Face-specific processing (e.g. the Face-inversion effect). Section 5 asks how the computations and representations in the FFA differ from those occurring in other nearby regions of cortex that respond strongly to Faces and objects. The evidence indicates clear functional dissociations between these regions, demonstrating that the FFA shows not only functional specificity but also Area specificity. We end by speculating in § 6o n some of the broader questions raised by current research on the FFA, including the developmental origins of this region and the question of whether Faces are unique versus whether similarly specialized mechanisms also exist for other domains of high-level perception and cognition.
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the Fusiform Face Area subserves Face perception not generic within category identification
Nature Neuroscience, 2004Co-Authors: Kalanit Grillspector, Nicholas Knouf, Nancy KanwisherAbstract:The function of the Fusiform Face Area (FFA), a Face-selective region in human extrastriate cortex, is a matter of active debate. Here we measured the correlation between FFA activity measured by functional magnetic resonance imaging (fMRI) and behavioral outcomes in perceptual tasks to determine the role of the FFA in the detection and within-category identification of Faces and objects. Our data show that FFA activation is correlated on a trial-by-trial basis with both detecting the presence of Faces and identifying specific Faces. However, for most non-Face objects (including cars seen by car experts), within-category identification performance was correlated with activation in other regions of the ventral occipitotemporal cortex, not the FFA. These results indicate that the FFA is involved in both detection and identification of Faces, but that it has little involvement in within-category identification of non-Face objects (including objects of expertise).
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RESPONSE PROPERTIES OF THE HUMAN Fusiform Face Area
Cognitive neuropsychology, 2000Co-Authors: Frank Tong, Ken Nakayama, Morris Moscovitch, Oren Weinrib, Nancy KanwisherAbstract:We used functional magnetic resonance imaging to study the response properties of the human Fusiform Face Area (FFA: Kanwisher, McDermott, & Chun, 1997) to a variety of Face-like stimuli in order to clarify the functional role of this region. FFA responses were found to be (1) equally strong for cat, cartoon and human Faces despite very different image properties, (2) equally strong for entire human Faces and Faces with eyes occluded but weaker for eyes shown alone, (3) equal for front and profile views of human heads, but declining in strength as Faces rotated away from view, and (4) weakest for nonFace objects and houses. These results indicate that generalisation of the FFA response across very different Face types cannot be explained in terms of a specific response to a salient facial feature such as the eyes or a more general response to heads. Instead, the FFA appears to be optimally tuned to the broad category of Faces.
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The Fusiform Face Area is selective for Faces not animals.
Neuroreport, 1999Co-Authors: Nancy Kanwisher, Damian A. Stanley, Alison HarrisAbstract:To test whether the human Fusiform Face Area (FFA) responds not only to Faces but to anything human or animate, we used fMRI to measure the response of the FFA to six new stimulus categories. The strongest responses were to stimuli containing Faces: human Faces (2.0% signal increase from fixation baseline) and human heads (1.7%), with weaker but still strong responses to whole humans (1.5%) and animal heads (1.3%). Responses to whole animals (1.0%) and human bodies without heads (1.0%) were significantly stronger than responses to inanimate objects (0.7%), but responses to animal bodies without heads (0.8%) were not. These results demonstrate that the FFA is selective for Faces, not for animals.
Galit Yovel - One of the best experts on this subject based on the ideXlab platform.
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Successful Decoding of Famous Faces in the Fusiform Face Area
PloS one, 2015Co-Authors: Vadim Axelrod, Galit YovelAbstract:What are the neural mechanisms of Face recognition? It is believed that the network of Face-selective Areas, which spans the occipital, temporal, and frontal cortices, is important in Face recognition. A number of previous studies indeed reported that Face identity could be discriminated based on patterns of multivoxel activity in the Fusiform Face Area and the anterior temporal lobe. However, given the difficulty in localizing the Face-selective Area in the anterior temporal lobe, its role in Face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior Face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous Faces in the temporo-frontal network of Face-selective and adjacent non-Face-selective regions. A special focus has been put on the Face-Area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that Face-identity could be discriminated above chance level only in the Fusiform Face Area. Our results corroborate the role of the Fusiform Face Area in Face recognition. Future studies are needed to further explore the role of the more recently discovered anterior Face-selective Areas in Face recognition.
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external facial features modify the representation of internal facial features in the Fusiform Face Area
NeuroImage, 2010Co-Authors: Vadim Axelrod, Galit YovelAbstract:Most studies of Face identity have excluded external facial features by either removing them or covering them with a hat. However, external facial features may modify the representation of internal facial features. Here we assessed whether the representation of Face identity in the Fusiform Face Area (FFA), which has been primarily studied for internal facial features, is modified by differences in external facial features. We presented Faces in which external and internal facial features were manipulated independently. Our findings show that the FFA was sensitive to differences in external facial features, but this effect was significantly larger when the external and internal features were aligned than misaligned. We conclude that the FFA generates a holistic representation in which the internal and the external facial features are integrated. These results indicate that to better understand real-life Face recognition both external and internal features should be included.
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Nonpreferred stimuli modify the representation of Faces in the Fusiform Face Area
Journal of cognitive neuroscience, 2010Co-Authors: Vadim Axelrod, Galit YovelAbstract:The ventral visual cortex has a modular organization in which discrete and well-defined regions show a much stronger response to certain object categories (e.g., Faces, bodies) than to other categories. The majority of previous studies have examined the response of these category-selective regions to isolated images of preferred or nonpreferred categories. Thus, little is known about the way these category-selective regions represent more complex visual stimuli, which include both preferred and nonpreferred stimuli. Here we examined whether glasses (nonpreferred) modify the representation of simultaneously presented Faces (preferred) in the Fusiform Face Area. We used an event-related fMR-adaptation paradigm in which Faces were presented with glasses either on or above the Face while subjects performed a Face or a glasses discrimination task. Our findings show that the sensitivity of the Fusiform Face Area to glasses was maximal when glasses were presented on the Face than above the Face during a Face discrimination task rather than during a glasses discrimination task. These findings suggest that nonpreferred stimuli may significantly modify the representation of preferred stimuli, even when they are task irrelevant. Future studies will determine whether this interaction is specific to Faces or may be found for other object categories in category-selective Areas.
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the Fusiform Face Area a cortical region specialized for the perception of Faces
Philosophical Transactions of the Royal Society B, 2006Co-Authors: Nancy Kanwisher, Galit YovelAbstract:Faces are among the most important visual stimuli we perceive, informing us not only about a person’s identity, but also about their mood, sex, age and direction of gaze. The ability to extract this information within a fraction of a second of viewing a Face is important for normal social interactions and has probably played a critical role in the survival of our primate ancestors. Considerable evidence from behavioural, neuropsychological and neurophysiological investigations supports the hypothesis that humans have specialized cognitive and neural mechanisms dedicated to the perception of Faces (the Face-specificity hypothesis). Here, we review the literature on a region of the human brain that appears to play a key role in Face perception, known as the Fusiform Face Area (FFA). Section 1 outlines the theoretical background for much of this work. The Face-specificity hypothesis falls squarely on one side of a longstanding debate in the fields of cognitive science and cognitive neuroscience concerning the extent to which the mind/brain is composed of: (i) special-purpose (‘domain-specific’) mechanisms, each dedicated to processing a specific kind of information (e.g. Faces, according to the Face-specificity hypothesis), versus (ii) general-purpose (‘domain-general’) mechanisms, each capable of operating on any kind of information. Face perception has long served both as one of the prime candidates of a domain-specific process and as a key target for attack by proponents of domain-general theories of brain and mind. Section 2 briefly reviews the prior literature on Face perception from behaviour and neurophysiology. This work supports the Face-specificity hypothesis and argues against its domain-general alternatives (the individuation hypothesis, the expertise hypothesis and others). Section 3 outlines the more recent evidence on this debate from brain imaging, focusing particularly on the FFA. We review the evidence that the FFA is selectively engaged in Face perception, by addressing (and rebutting) five of the most widely discussed alternatives to this hypothesis. In §4, we consider recent findings that are beginning to provide clues into the computations conducted in the FFA and the nature of the representations the FFA extracts from Faces. We argue that the FFA is engaged both in detecting Faces and in extracting the necessary perceptual information to recognize them, and that the properties of the FFA mirror previously identified behavioural signatures of Face-specific processing (e.g. the Face-inversion effect). Section 5 asks how the computations and representations in the FFA differ from those occurring in other nearby regions of cortex that respond strongly to Faces and objects. The evidence indicates clear functional dissociations between these regions, demonstrating that the FFA shows not only functional specificity but also Area specificity. We end by speculating in § 6o n some of the broader questions raised by current research on the FFA, including the developmental origins of this region and the question of whether Faces are unique versus whether similarly specialized mechanisms also exist for other domains of high-level perception and cognition.
Vadim Axelrod - One of the best experts on this subject based on the ideXlab platform.
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Face-selective neurons in the vicinity of the human Fusiform Face Area
Neurology, 2019Co-Authors: Vadim Axelrod, Camille Rozier, Tal Seidel Malkinson, Katia Lehongre, Claude Adam, Virginie Lambrecq, Vincent Navarro, Lionel NaccacheAbstract:Face perception is thought to be mediated by neural activity in the occipital and posterior temporal cortex.1,2 However, the Face-selective neurons at the cellular level in these Areas in humans have never been demonstrated. We had a rare opportunity to record intracranial multi-unit activity in an epilepsy patient near the Fusiform Face Area2 (figure 1A). We identified 2 units with highly Face-selective response to static images of familiar (famous) and unfamiliar Faces (figure 1B and video 1; figure e-1a, doi.org/10.5061/dryad.81t0fq1) as well as to human and animal Faces that appeared in a movie (figure 1C, video 1, figure e-1b).
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Face-selective neurons in the vicinity of the human Fusiform Face Area
2019Co-Authors: Vadim Axelrod, Camille Rozier, Tal Seidel Malkinson, Katia Lehongre, Claude Adam, Virginie Lambrecq, Vincent Navarro, Lionel NaccacheAbstract:This is supplementary materials to the paper: "Face-selective neurons in the vicinity of the human Fusiform Face Area
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Successful Decoding of Famous Faces in the Fusiform Face Area
PloS one, 2015Co-Authors: Vadim Axelrod, Galit YovelAbstract:What are the neural mechanisms of Face recognition? It is believed that the network of Face-selective Areas, which spans the occipital, temporal, and frontal cortices, is important in Face recognition. A number of previous studies indeed reported that Face identity could be discriminated based on patterns of multivoxel activity in the Fusiform Face Area and the anterior temporal lobe. However, given the difficulty in localizing the Face-selective Area in the anterior temporal lobe, its role in Face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior Face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous Faces in the temporo-frontal network of Face-selective and adjacent non-Face-selective regions. A special focus has been put on the Face-Area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that Face-identity could be discriminated above chance level only in the Fusiform Face Area. Our results corroborate the role of the Fusiform Face Area in Face recognition. Future studies are needed to further explore the role of the more recently discovered anterior Face-selective Areas in Face recognition.
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external facial features modify the representation of internal facial features in the Fusiform Face Area
NeuroImage, 2010Co-Authors: Vadim Axelrod, Galit YovelAbstract:Most studies of Face identity have excluded external facial features by either removing them or covering them with a hat. However, external facial features may modify the representation of internal facial features. Here we assessed whether the representation of Face identity in the Fusiform Face Area (FFA), which has been primarily studied for internal facial features, is modified by differences in external facial features. We presented Faces in which external and internal facial features were manipulated independently. Our findings show that the FFA was sensitive to differences in external facial features, but this effect was significantly larger when the external and internal features were aligned than misaligned. We conclude that the FFA generates a holistic representation in which the internal and the external facial features are integrated. These results indicate that to better understand real-life Face recognition both external and internal features should be included.
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The Fusiform Face Area: in quest of holistic Face processing.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2010Co-Authors: Vadim AxelrodAbstract:What role do external facial features (hair, moustaches, beards, etc.) play in Face recognition? Many of us have experienced the difficulty of recognizing a friend or a colleague who had changed her hairstyle or had shaved his beard. Such a change seems like not just a change in the facial hair, but
Rankin W. Mcgugin - One of the best experts on this subject based on the ideXlab platform.
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Thickness of Deep Layers in the Fusiform Face Area Predicts Face Recognition.
Journal of cognitive neuroscience, 2020Co-Authors: Rankin W. Mcgugin, Allen T. Newton, Benjamin J. Tamber-rosenau, Andrew J. Tomarken, Isabel GauthierAbstract:People with superior Face recognition have relatively thin cortex in Face-selective brain Areas, whereas those with superior vehicle recognition have relatively thick cortex in the same Areas. We s...
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Thickness of deep layers in the Fusiform Face Area predicts Face recognition
2019Co-Authors: Rankin W. Mcgugin, Allen T. Newton, Benjamin J. Tamber-rosenau, Andrew J. Tomarken, Isabel GauthierAbstract:Abstract People with superior Face recognition have relatively thin cortex in Face-selective brain Areas, while those with superior vehicle recognition have relatively thick cortex in the same Areas. We suggest that these opposite correlations reflect distinct mechanisms influencing cortical thickness (CT) for abilities acquired at different points in development. We explore a new prediction regarding the specificity of these effects through the depth of the cortex: that Face recognition selectively and negatively correlates with thickness of the deepest laminar subdivision in Face-selective Areas. With ultra-high resolution MRI at 7T, we estimated the thickness of three laminar subdivisions, which we term MR layers, in the right Fusiform Face Area (rFFA) in 14 adult male humans. Face recognition was negatively associated with the thickness of deep MR layers, while vehicle recognition was positively related to the thickness of all layers. Regression model comparisons provided overwhelming support for a model specifying that the magnitude of the association between Face recognition and CT differs across MR layers (deep vs. superficial/middle) while the magnitude of the association between vehicle recognition and CT is invariant across layers. The total CT of rFFA accounted for 69% of the variance in Face recognition, and thickness of the deep layer alone accounted for 84% of this variance. Our findings demonstrate the functional validity of MR laminar estimates in FFA. Studying the structural basis of individual differences for multiple abilities in the same cortical Area can reveal effects of distinct mechanisms that are not apparent when studying average variation or development. Significance Statement Face and object recognition vary in the normal population and are only modestly related to each other. The recognition of Faces and vehicles are both positively related to neural responses in the Fusiform Face Area (FFA), but show different relations to the cortical thickness of FFA. Here, we use very high-resolution MRI, and find that Face recognition ability (a skill acquired early in life) is negatively correlated with thickness of FFA’s deepest MR-defined layers, whereas recognition of vehicles (a skill acquired later in life) is positively related to thickness at of all cortical layers. Our methods can be used in the future to characterize sources of variability in human abilities and relate them to distinct mechanisms of neural plasticity.
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cortical thickness in Fusiform Face Area predicts Face and object recognition performance
Journal of Cognitive Neuroscience, 2016Co-Authors: Rankin W. Mcgugin, Ana Van Gulick, Isabel GauthierAbstract:The Fusiform Face Area FFA is defined by its selectivity for Faces. Several studies have shown that the response of FFA to nonFace objects can predict behavioral performance for these objects. However, one possible account is that experts pay more attention to objects in their domain of expertise, driving signals up. Here, we show an effect of expertise with nonFace objects in FFA that cannot be explained by differential attention to objects of expertise. We explore the relationship between cortical thickness of FFA and Face and object recognition using the Cambridge Face Memory Test and Vanderbilt Expertise Test, respectively. We measured cortical thickness in functionally defined regions in a group of men who evidenced functional expertise effects for cars in FFA. Performance with Faces and objects together accounted for approximately 40% of the variance in cortical thickness of several FFA patches. Whereas participants with a thicker FFA cortex performed better with vehicles, those with a thinner FFA cortex performed better with Faces and living objects. The results point to a domain-general role of FFA in object perception and reveal an interesting double dissociation that does not contrast Faces and objects but rather living and nonliving objects.
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high resolution imaging of expertise reveals reliable object selectivity in the Fusiform Face Area related to perceptual performance
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Rankin W. Mcgugin, J C Gatenby, John C Gore, Isabel GauthierAbstract:The Fusiform Face Area (FFA) is a region of human cortex that responds selectively to Faces, but whether it supports a more general function relevant for perceptual expertise is debated. Although both Faces and objects of expertise engage many brain Areas, the FFA remains the focus of the strongest modular claims and the clearest predictions about expertise. Functional MRI studies at standard-resolution (SR-fMRI) have found responses in the FFA for nonFace objects of expertise, but high-resolution fMRI (HR-fMRI) in the FFA [Grill-Spector K, et al. (2006) Nat Neurosci 9:1177–1185] and neurophysiology in Face patches in the monkey brain [Tsao DY, et al. (2006) Science 311:670–674] reveal no reliable selectivity for objects. It is thus possible that FFA responses to objects with SR-fMRI are a result of spatial blurring of responses from nonFace-selective Areas, potentially driven by attention to objects of expertise. Using HR-fMRI in two experiments, we provide evidence of reliable responses to cars in the FFA that correlate with behavioral car expertise. Effects of expertise in the FFA for nonFace objects cannot be attributed to spatial blurring beyond the scale at which modular claims have been made, and within the lateral Fusiform gyrus, they are restricted to a small Area (200 mm2 on the right and 50 mm2 on the left) centered on the peak of Face selectivity. Experience with a category may be sufficient to explain the spatially clustered Face selectivity observed in this region.
