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Martin Eimer - One of the best experts on this subject based on the ideXlab platform.
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event related brain potentials distinguish processing stages involved in face perception and recognition
Clinical Neurophysiology, 2000Co-Authors: Martin EimerAbstract:Objectives: An event-related brain potential (ERP) study investigated how different processing stages involved in face identification are reflected by ERP modulations, and how stimulus repetitions and attentional set influence such effects. Methods: ERPs were recorded in response to photographs of familiar faces, unfamiliar faces, and houses. In Part I, participants had to detect infrequently presented targets (hands), in Part II, attention was either directed towards or away from the pictorial stimuli. Results: The face-specific N170 component elicited maximally at lateral temporal electrodes was not affected by face familiarity. When compared with unfamiliar faces, familiar faces elicited an enhanced negativity between 300 and 500 ms (‘N400f’) which was followed by an enhanced positivity beyond 500 ms post-stimulus (‘P600f’). In contrast to the ‘classical’ N400, these effects were parietocentrally distributed. They were attenuated, but still reliable, for repeated presentations of familiar faces. When attention was directed to another demanding task, no ‘N400f’ was elicited, but the ‘P600f’ effect remained to be present. Conclusions: While the N170 reflects the pre-categorical structural encoding of faces, the ‘N400f’ and ‘P600f’ are likely to indicate subsequent processes involved in face recognition. Impaired structural encoding can result in the disruption of face identification. This is illustrated by a neuropsychological case study, demonstrating the absence of the N170 and later ERP indicators of face recognition in a Prosopagnosic Patient. q 2000 Elsevier Science Ireland Ltd. All rights reserved.
Rossion Bruno - One of the best experts on this subject based on the ideXlab platform.
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The cortical face network of the Prosopagnosic Patient PS with fast periodic stimulation in fMRI
Elsevier, 2019Co-Authors: Gao Xiaoqing, Vuong Quoc, Rossion BrunoAbstract:International audienceFollowing brain damage, the Patient PS suffers from selective impairment in recognizing individuals by their faces, i.e., prosopagnosia. Her case has been documented in more than 30 publications to date, informing about the nature of individual face recognition and its neural basis. Here we report new functional neuroimaging data obtained on PS with a recently developed fast periodic stimulation functional imaging (FPS-fMRI) paradigm combining high sensitivity, specificity and reliability in identifying the cortical face-selective network (Gao et al., 2018). We define the extent of the large and reliable face-selective activation in the lateral section of the right middle fusiform gyrus, i.e., right FFA, which forms a single cluster of activation lying at the anterior border of the Patient's main lesion in the inferior occipital gyrus. The contribution of posterior face-selective responses in the right or left inferior occipital gyrus is ruled out, strongly supporting the view that face-selective activity emerges in the right middle fusiform gyrus of the Patient's brain from non-face-selective inputs from early visual areas. Despite this, low-level visual cues, i.e., amplitude spectrum of images, do not contribute to neural face-selective responses anywhere in the Patient's cortical face network. This sensitive face-localizer approach also reveals an intact face-selective network anterior to the fusiform gyrus, including clusters in the ventral anterior temporal lobe (occipito-temporal sulcus and temporal pole) and the inferior frontal gyrus, with a right hemispheric dominance. Overall, with the exception of the left inferior occipital gyrus, the cortical face network of the Prosopagnosic Patient PS appears remarkably similar to typical individuals in non-brain damaged regions. However, unlike in neurotypical adults tested in the present study, including age-matched controls, a novel paradigm based on FPS-FMRI confirms that the Patient's face network is insensitive to differences between rapidly presented pictures of unfamiliar individual faces, in line with her prosopagnosia
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The cortical face network of the Prosopagnosic Patient PS with fast periodic stimulation in fMRI.
'Elsevier BV', 2019Co-Authors: Gao Xiaoqing, Vuong, Quoc C, Rossion BrunoAbstract:Following brain damage, the Patient PS suffers from selective impairment in recognizing individuals by their faces, i.e., prosopagnosia. Her case has been documented in more than 30 publications to date, informing about the nature of individual face recognition and its neural basis. Here we report new functional neuroimaging data obtained on PS with a recently developed fast periodic stimulation functional imaging (FPS-fMRI) paradigm combining high sensitivity, specificity and reliability in identifying the cortical face-selective network (Gao et al., 2018). We define the extent of the large and reliable face-selective activation in the lateral section of the right middle fusiform gyrus, i.e., right FFA, which forms a single cluster of activation lying at the anterior border of the Patient's main lesion in the inferior occipital gyrus. The contribution of posterior face-selective responses in the right or left inferior occipital gyrus is ruled out, strongly supporting the view that face-selective activity emerges in the right middle fusiform gyrus of the Patient's brain from non-face-selective inputs from early visual areas. Despite this, low-level visual cues, i.e., amplitude spectrum of images, do not contribute to neural face-selective responses anywhere in the Patient's cortical face network. This sensitive face-localizer approach also reveals an intact face-selective network anterior to the fusiform gyrus, including clusters in the ventral anterior temporal lobe (occipito-temporal sulcus and temporal pole) and the inferior frontal gyrus, with a right hemispheric dominance. Overall, with the exception of the left inferior occipital gyrus, the cortical face network of the Prosopagnosic Patient PS appears remarkably similar to typical individuals in non-brain damaged regions. However, unlike in neurotypical adults tested in the present study, including age-matched controls, a novel paradigm based on FPS-FMRI confirms that the Patient's face network is insensitive to differences between rapidly presented pictures of unfamiliar individual faces, in line with her prosopagnosia
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Face-specific impairment in holistic perception following focal lesion of the right anterior temporal lobe
'Elsevier BV', 2014Co-Authors: Busigny Thomas, Van Belle Goedele, Jemel Boutheina, Hosein Anthony, Joubert Sven, Rossion BrunoAbstract:Recent studies have provided solid evidence for pure cases of prosopagnosia following brain damage. The Patients reported so far have posterior lesions encompassing either or both the right inferior occipital cortex and fusiform gyrus, and exhibit a critical impairment in generating a sufficiently detailed holistic percept to individualize faces. Here, we extended these observations to include the Prosopagnosic Patient LR (Bukach, Bub, Gauthier, & Tarr, 2006), whose damage is restricted to the anterior region of the right temporal lobe. First, we report that LR is able to discriminate parametrically defined individual exemplars of nonface object categories as accurately and quickly as typical observers, which suggests that the visual similarity account of prosopagnosia does not explain his impairments. Then, we show that LR does not present with the typical face inversion effect, whole-part advantage, or composite face effect and, therefore, has impaired holistic perception of individual faces. Moreover, the Patient is more impaired at matching faces when the facial part he fixates is masked than when it is selectively revealed by means of gaze contingency. Altogether these observations support the view that the nature of the critical face impairment does not differ qualitatively across Patients with acquired prosopagnosia, regardless of the localization of brain damage: all these Patients appear to be impaired to some extent at what constitutes the heart of our visual expertise with faces, namely holistic perception at a sufficiently fine-grained level of resolution to discriminate exemplars of the face class efficiently. This conclusion raises issues regarding the existing criteria for diagnosis/classification of Patients as cases of apperceptive or associative prosopagnosia
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Is the loss of diagnosticity of the eye region of the face a common aspect of acquired prosopagnosia?
'Wiley', 2009Co-Authors: Rossion Bruno, Kaiser, Martha D, Bub Daniel, Tanaka, James WAbstract:A recent study published in this journal has shown an abnormal performance at discriminating differences with respect to the eyes of unfamiliar faces in two acquired Prosopagnosic Patients, but preserved processing of the mouth region. Here we extend these findings by showing a similar lack of sensitivity to the eyes in the very same face matching experiment for the Prosopagnosic Patient PS, who also showed normal performance for detecting differences in the mouth region. These results complement previously published evidence that the Patient PS presents a lack of sensitivity to diagnostic information located on the eyes of familiar faces during individual face recognition tasks. More generally, they indicate that the impaired processing of the eyes of faces is a fundamental aspect of acquired prosopagnosia that can arise following damage to different brain localizations
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Reduced fixation on the upper area of personally familiar faces following acquired prosopagnosia
'Wiley', 2008Co-Authors: Orban De Xivry, Jean-jacques, Ramon Meike, Lefèvre Philippe, Rossion BrunoAbstract:Selective impairment of face recognition following brain damage, as in acquired prosopagnosia, may cause a dramatic loss of diagnosticity of the eye area of the face and an increased reliance on the mouth for identification (Caldara et al., 2005). To clarify the nature of this phenomenon, we measured eye fixation patterns in a case of pure prosopagnosia (PS, Rossion et al., 2003) during her identification of photographs of personally familiar faces (27 children of her kindergarten). Her age-matched colleague served as a control. Consistent with previous evidence, the normal control identified the faces within two fixations located just below the eyes (central upper nose). This pattern (location and duration) of fixations remained unchanged even by increasing difficulty by presenting anti-caricatures of the faces. In contrast, the great majority of the Patient's fixations, irrespective of her accuracy, were located on the mouth. Overall, these observations confirm the abnormally reduced processing of the upper area of the face in acquired prosopagnosia. Most importantly, the Prosopagnosic Patient also fixated the area of the eyes spontaneously in between the first and last fixation, ruling out alternative accounts of her behaviour such as, for example, avoidance or failure to orient attention to the eyes, as observed in autistic or bilateral amygdala Patients. Rather, they reinforce our proposal of a high-level perceptual account (Caldara et al., 2005), according to which acquired Prosopagnosic Patients have lost the ability to represent multiple elements of an individual face as a perceptual unit (holistic face perception). To identify a given face, they focus very precisely on local features rather than seeing the whole of a face from its diagnostic centre (i.e., just below the eyes). The upper area of the face is particularly less attended to and less relevant for the Prosopagnosic Patient because it contains multiple features that require normal holistic perception in order to be the most diagnostic region. Consequently, Prosopagnosic Patients develop a more robust representation of the mouth, a relatively isolated feature in the face that may contain more information than any single element of the upper face area, and is thus sampled repeatedly for resolving ambiguity in the process of identification.status: publishe
Bruno Rossion - One of the best experts on this subject based on the ideXlab platform.
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Holistic face categorization in higher-level cortical visual areas of the normal and Prosopagnosic brain: towards a non-hierarchical view of face perception
Frontiers Media S.A., 2011Co-Authors: Bruno Rossion, Laurence Dricot, Rainer Goebel, Thomas BusignyAbstract:How a visual stimulus is initially categorized as a face in a network of human brain areas remains largely unclear. Hierarchical neuro-computational models of face perception assume that the visual stimulus is first decomposed in local parts in lower order visual areas. These parts would then be combined into a global representation in higher order face-sensitive areas of the occipito-temporal cortex. Here we tested this view in fMRI with visual stimuli that are categorized as faces based on their global configuration rather than their local parts (2-tones Mooney figures and Arcimboldo’s facelike paintings). Compared to the same inverted visual stimuli that are not categorized as faces, these stimuli activated the right middle fusiform gyrus (Fusiform face area, FFA) and superior temporal sulcus (pSTS), with no significant activation in the posteriorly located inferior occipital gyrus (i.e., no occipital face area, OFA). This observation is strengthened by behavioral and neural evidence for normal face categorization of these stimuli in a brain-damaged Prosopagnosic Patient (PS) whose intact right middle fusiform gyrus and superior temporal sulcus are devoid of any potential face-sensitive inputs from the lesioned right inferior occipital cortex. Together, these observations indicate that face-preferential activation may emerge in higher order visual areas of the right hemisphere without any face-preferential inputs from lower order visual areas, supporting a non-hierarchical view of face perception in the visual cortex
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holistic face categorization in higher order visual areas of the normal and Prosopagnosic brain toward a non hierarchical view of face perception
Frontiers in Human Neuroscience, 2011Co-Authors: Bruno Rossion, Laurence Dricot, Rainer Goebel, Thomas BusignyAbstract:How a visual stimulus is initially categorized as a face in a network of human brain areas remains largely unclear. Hierarchical neuro-computational models of face perception assume that the visual stimulus is first decomposed in local parts in lower order visual areas. These parts would then be combined into a global representation in higher order face-sensitive areas of the occipito-temporal cortex. Here we tested this view in fMRI with visual stimuli that are categorized as faces based on their global configuration rather than their local parts (two-tones Mooney figures and Arcimboldo's facelike paintings). Compared to the same inverted visual stimuli that are not categorized as faces, these stimuli activated the right middle fusiform gyrus ("Fusiform face area") and superior temporal sulcus (pSTS), with no significant activation in the posteriorly located inferior occipital gyrus (i.e., no "occipital face area"). This observation is strengthened by behavioral and neural evidence for normal face categorization of these stimuli in a brain-damaged Prosopagnosic Patient whose intact right middle fusiform gyrus and superior temporal sulcus are devoid of any potential face-sensitive inputs from the lesioned right inferior occipital cortex. Together, these observations indicate that face-preferential activation may emerge in higher order visual areas of the right hemisphere without any face-preferential inputs from lower order visual areas, supporting a non-hierarchical view of face perception in the visual cortex.
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acquired prosopagnosia as a face specific disorder ruling out the general visual similarity account
Neuropsychologia, 2010Co-Authors: Thomas Busigny, Markus Graf, Eugene Mayer, Bruno RossionAbstract:Prosopagnosia is classically defined as a disorder of visual recognition specific to faces, following brain damage. However, according to a long-standing alternative view, these Patients would rather be generally impaired in recognizing objects belonging to visually homogenous categories, including faces. We tested this alternative hypothesis stringently with a well-documented brain-damaged Prosopagnosic Patient (PS) in three delayed forced-choice recognition experiments in which visual similarity between a target and its distractor was manipulated parametrically: novel 3D geometric shapes, morphed pictures of common objects, and morphed photographs of a highly homogenous familiar category (cars). In all experiments, PS showed normal performance and speed, and there was no evidence of a steeper increase of error rates and RTs with increasing levels of visual similarity, compared to controls. These data rule out an account of acquired prosopagnosia in terms of a more general impairment in recognizing objects from visually homogenous categories. An additional experiment with morphed faces confirmed that PS was specifically impaired at individual face recognition. However, in stark contrast to the alternative view of prosopagnosia, PS was relatively more impaired at the easiest levels of discrimination, i.e. when individual faces differ clearly in global shape rather than when faces were highly similar and had to be discriminated based on fine-grained details. Overall, these observations as well as a review of previous evidence, lead us to conclude that this alternative view of prosopagnosia does not hold. Rather, it seems that brain damage in adulthood may lead to selective recognition impairment for faces, perhaps the only category of visual stimuli for which holistic/configural perception is not only potentially at play, but is strictly necessary to individualize members of the category efficiently.
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Evidence for individual face discrimination in non-face selective areas of the visual cortex in acquired prosopagnosia.
Behavioural neurology, 2008Co-Authors: Laurence Dricot, Rainer Goebel, Bettina Sorger, Christine Schiltz, Bruno RossionAbstract:Two areas in the human occipito-temporal cortex respond preferentially to faces: 'the fusiform face area' ('FFA') and the 'occipital face area' ('OFA'). However, it is unclear whether these areas have an exclusive role in processing faces, or if sub-maximal responses in other visual areas such as the lateral occipital complex (LOC) are also involved. To clarify this issue, we tested a brain-damaged Patient (PS) presenting a face-selective impairment with functional magnetic resonance imaging (fMRI). The right hemisphere lesion of the Prosopagnosic Patient encompasses the 'OFA' but preserves the 'FFA' and LOC. Using fMRI-adaptation, we found a larger response to different faces than repeated faces in the ventral part of the LOC both for normals and the Patient, next to her right hemisphere lesion. This observation indicates that following prosopagnosia, areas that do not respond preferentially to faces such as the ventral part of the LOC (vLOC) may still be recruited to subtend residual perception of individual faces.
Thomas Busigny - One of the best experts on this subject based on the ideXlab platform.
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holistic face categorization in higher order visual areas of the normal and Prosopagnosic brain toward a non hierarchical view of face perception
Frontiers in Human Neuroscience, 2011Co-Authors: Bruno Rossion, Laurence Dricot, Rainer Goebel, Thomas BusignyAbstract:How a visual stimulus is initially categorized as a face in a network of human brain areas remains largely unclear. Hierarchical neuro-computational models of face perception assume that the visual stimulus is first decomposed in local parts in lower order visual areas. These parts would then be combined into a global representation in higher order face-sensitive areas of the occipito-temporal cortex. Here we tested this view in fMRI with visual stimuli that are categorized as faces based on their global configuration rather than their local parts (two-tones Mooney figures and Arcimboldo's facelike paintings). Compared to the same inverted visual stimuli that are not categorized as faces, these stimuli activated the right middle fusiform gyrus ("Fusiform face area") and superior temporal sulcus (pSTS), with no significant activation in the posteriorly located inferior occipital gyrus (i.e., no "occipital face area"). This observation is strengthened by behavioral and neural evidence for normal face categorization of these stimuli in a brain-damaged Prosopagnosic Patient whose intact right middle fusiform gyrus and superior temporal sulcus are devoid of any potential face-sensitive inputs from the lesioned right inferior occipital cortex. Together, these observations indicate that face-preferential activation may emerge in higher order visual areas of the right hemisphere without any face-preferential inputs from lower order visual areas, supporting a non-hierarchical view of face perception in the visual cortex.
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Holistic face categorization in higher-level cortical visual areas of the normal and Prosopagnosic brain: towards a non-hierarchical view of face perception
Frontiers Media S.A., 2011Co-Authors: Bruno Rossion, Laurence Dricot, Rainer Goebel, Thomas BusignyAbstract:How a visual stimulus is initially categorized as a face in a network of human brain areas remains largely unclear. Hierarchical neuro-computational models of face perception assume that the visual stimulus is first decomposed in local parts in lower order visual areas. These parts would then be combined into a global representation in higher order face-sensitive areas of the occipito-temporal cortex. Here we tested this view in fMRI with visual stimuli that are categorized as faces based on their global configuration rather than their local parts (2-tones Mooney figures and Arcimboldo’s facelike paintings). Compared to the same inverted visual stimuli that are not categorized as faces, these stimuli activated the right middle fusiform gyrus (Fusiform face area, FFA) and superior temporal sulcus (pSTS), with no significant activation in the posteriorly located inferior occipital gyrus (i.e., no occipital face area, OFA). This observation is strengthened by behavioral and neural evidence for normal face categorization of these stimuli in a brain-damaged Prosopagnosic Patient (PS) whose intact right middle fusiform gyrus and superior temporal sulcus are devoid of any potential face-sensitive inputs from the lesioned right inferior occipital cortex. Together, these observations indicate that face-preferential activation may emerge in higher order visual areas of the right hemisphere without any face-preferential inputs from lower order visual areas, supporting a non-hierarchical view of face perception in the visual cortex
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acquired prosopagnosia as a face specific disorder ruling out the general visual similarity account
Neuropsychologia, 2010Co-Authors: Thomas Busigny, Markus Graf, Eugene Mayer, Bruno RossionAbstract:Prosopagnosia is classically defined as a disorder of visual recognition specific to faces, following brain damage. However, according to a long-standing alternative view, these Patients would rather be generally impaired in recognizing objects belonging to visually homogenous categories, including faces. We tested this alternative hypothesis stringently with a well-documented brain-damaged Prosopagnosic Patient (PS) in three delayed forced-choice recognition experiments in which visual similarity between a target and its distractor was manipulated parametrically: novel 3D geometric shapes, morphed pictures of common objects, and morphed photographs of a highly homogenous familiar category (cars). In all experiments, PS showed normal performance and speed, and there was no evidence of a steeper increase of error rates and RTs with increasing levels of visual similarity, compared to controls. These data rule out an account of acquired prosopagnosia in terms of a more general impairment in recognizing objects from visually homogenous categories. An additional experiment with morphed faces confirmed that PS was specifically impaired at individual face recognition. However, in stark contrast to the alternative view of prosopagnosia, PS was relatively more impaired at the easiest levels of discrimination, i.e. when individual faces differ clearly in global shape rather than when faces were highly similar and had to be discriminated based on fine-grained details. Overall, these observations as well as a review of previous evidence, lead us to conclude that this alternative view of prosopagnosia does not hold. Rather, it seems that brain damage in adulthood may lead to selective recognition impairment for faces, perhaps the only category of visual stimuli for which holistic/configural perception is not only potentially at play, but is strictly necessary to individualize members of the category efficiently.
Andrew W Young - One of the best experts on this subject based on the ideXlab platform.
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automatic without autonomic responses to familiar faces differential components of covert face recognition in a case of capgras delusion
Cognitive Neuropsychiatry, 2000Co-Authors: Michael B Lewis, Hamdy Moselhy, Andrew W YoungAbstract:Introduction. This study was designed to elucidate the relationship between different types of covert face recognition. Some Patients with prosopagnosia (i.e., the profound inability to recognise previously familiar faces) nonetheless evince autonomic face recognition (elevated skin-conductance levels to familiar faces) or behavioural indices of covert recognition (i.e., priming; interference effects; matching effects; face-name learning). One Prosopagnosic Patient revealed both autonomic and behavioural covert face recognition-which suggests they may arise from some common basis. Method. To test this claim a Patient with the Capgras delusion (i.e., holding the belief that others have been replaced by impostors, etc.) was tested on each type of covert face recognition and her results compared with agematched controls. We know that the Capgras delusion is characterised by good overt or conscious face recognition coupled with the absence of autonomic discrimination between familiar and unfamiliar faces. The question addressed here was whether, compared with age- and gender-matched controls, the Patient, B.P., would show neither autonomic nor behavioural covert face recognition. Results. The answer was that, although she showed no autonomic discrimination, her performance on a priming task and a test of face/name interference were normal. The controls, as expected, revealed covert face recognition on both the autonomic and behavioural measures. Conclusions. The results imply in B.P. a clear dissociation between autonomic and behavioural measures of covert face recognition. The theoretical implications of these results are discussed.
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Automatic without autonomic responses to familiar faces: Differential components of implicit face recognition in a case of Capgras delusion
2000Co-Authors: Michael B Lewis, Hamdy Moselhy, Andrew W YoungAbstract:Introduction. This study was designed to elucidatethe relationshipbetween different types of covert face recognition. Some Patients with prosopagnosia (i.e., the profound inability to recognise previously familiar faces) nonetheless evince autonomic face recognition (elevated skin-conductance levels to familiar faces) or behavioural indices of covert recognition (i.e., priming; interference effects; matching effects; face-name learning). One Prosopagnosic Patient revealed both autonomic and behaviouralcovert face recognition-which suggests they may arise from some common basis. Method. To test this claim a Patient with the Capgras delusion (i.e., holding the belief that others have been replaced by impostors, etc.) was tested on each type of covert face recognitionand her results compared with agematched controls. We know that the Capgras delusion is characterised by good overt or conscious face recognitioncoupled with the absence of autonomic discrimination between familiar and unfamiliar faces. The question addressed here was whether, compared with age-and gender-matched controls, the Patient, B.P., would show neither autonomic nor behaviouralcovert face recognition.Results. The answer was that, although she showed no autonomic discrimination, her performance on a priming task and a test of face/name interference were normal. The controls, as expected, revealed covert face recognition on both the autonomic and behavioural measures. Conclusions. The results imply in B.P. a clear dissociation between autonomic and behavioural measures of covert face recognition. The theoretical implications of these results are discussed
