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Absence of any developmental trend in right hemisphere superiority for face recognition.

Upright or inverted pictures of faces were presented bilaterally, with one face falling in each visual hemifield, to right-handed children aged seven, ten and thirteen years. When a small set of four stimulus faces was used with each child (Experiment I) both boys and girls were found to be better at recognising upright faces falling in the left visual hemifield (LVF). For inverted faces there was no difference between the visual hemifields. When a set of forty stimulus faces was used (Experiment II), boys only were found to be better at recognising upright faces falling in the LVF. These results are interpreted in terms of superiority of the right cerebral hemisphere for processing upright faces. No developmental differences in the degree of this superiority were found in the age range studied.

Adolescent↗

The effect of encoding strategy on the neural correlates of memory for faces.

Encoding and recognition of unfamiliar faces in young adults were examined using positron emission tomography to determine whether different encoding strategies would lead to encoding/retrieval differences in brain activity. Three types of encoding were compared: a 'deep' task (judging pleasantness/unpleasantness), a 'shallow' task (judging right/left orientation), and an intentional learning task in which subjects were instructed to learn the faces for a subsequent memory test but were not provided with a specific strategy. Memory for all faces was tested with an old/new recognition test. A modest behavioral effect was obtained, with deeply-encoded faces being recognized more accurately than shallowly-encoded or intentionally-learned faces. Regardless of encoding strategy, encoding activated a primarily ventral system including bilateral temporal and fusiform regions and left prefrontal cortices, whereas recognition activated a primarily dorsal set of regions including right prefrontal and parietal areas. Within encoding, the type of strategy produced different brain activity patterns, with deep encoding being characterized by left amygdala and left anterior cingulate activation. There was no effect of encoding strategy on brain activity during the recognition conditions. Posterior fusiform gyrus activation was related to better recognition accuracy in those conditions encouraging perceptual strategies, whereas activity in left frontal and temporal areas correlated with better performance during the 'deep' condition. Results highlight three important aspects of face memory: (1) the effect of encoding strategy was seen only at encoding and not at recognition; (2) left inferior prefrontal cortex was engaged during encoding of faces regardless of strategy; and (3) differential activity in fusiform gyrus was found, suggesting that activity in this area is not only a result of automatic face processing but is modulated by controlled processes.

Adult↗

Configurational coding, familiarity and the right hemisphere advantage for face recognition in sheep.

This study examined characteristics of visual recognition of familiar and unfamiliar faces in sheep using a 2-way discrimination task. Of particular interest were effects of lateralisation and the differential use of internal (configurational) vs external features of the stimuli. Animals were trained in a Y-maze to identify target faces from pairs, both of which were familiar (same flock as the subjects) or both of which were unfamiliar (different flock). Having been trained to identify the rewarded face a series of stimuli were presented to the sheep, designed to test for the use of each visual hemifield in the discriminations and the use of internal and external facial cues. The first experiment showed that there was a left visual hemifield (LVF) advantage in the identification of 'hemifaces', and 'mirrored hemifaces' and 'chimeric' faces and that this effect was strongest with familiar faces. This represents the first evidence for visual field bias outside the primate literature. Results from the second experiment showed that, whilst both familiar and unfamiliar faces could be identified by the external features alone, only the familiar faces could be recognised by the internal features alone. Overall the results suggest separate recognition methods for socially familiar and unfamiliar faces, with the former being coded more by internal, configurational cues and showing a lateral bias to the left visual field.

Animals↗

Faces call for attention: evidence from patients with visual extinction.

Three patients with left spatial neglect and visual extinction from right brain damage were studied to determine whether faces are privileged in summoning attention. In a first experiment, either a face, a name, or a meaningless shape were briefly presented in the right, left or both visual hemifields. On bilateral trials, all patients extinguished a left-side face much less often than a left-side name or a left-side shape. Conversely, they extinguished a left-side shape more often when it was accompanied by a right-side face rather than a right-side name. In a second experiment, either a face or a scrambled face could appear in the right, left or both hemifields. Again, on bilateral trials, a left-side face was less likely to be missed than a scrambled one. These results suggest an advantage of faces in capturing attention and overcoming extinction, which may be related to their special biological and social value, or to the very efficient and automatic operation of specific perceptual processses that extract facial organization in extrastriate visual areas. These findings also demonstrate that the distribution of spatial attention and extinction can be modulated by the relevance of visual stimuli. This implies that substantial analysis and categorization may take place in the visual system before information from the contralesional field is selected for, or excluded from, attentive vision.

Aged↗

[False recognition of faces associated with fronto-temporal dementia with prosopagnosia].

INTRODUCTION: The association of prosopagnosia and false recognition of faces is unusual and contributes to our understanding of the generation of facial familiarity. METHOD: A 67-year-old man with a left prefrontal traumatic lesion, developed a temporal variety of fronto-temporal dementia (semantic dementia) with amyotrophic lateral sclerosis. Cerebral imagery demonstrated a bilateral, temporal anterior atrophy predominating in the right hemisphere. The main cognitive signs consisted in severe difficulties to recognize faces of familiar people (prosopagnosia), associated with systematic false recognition of unfamiliar people. RESULT: Neuropsychological testing indicated that the prosopagnosia probably resulted from the association of an associative/mnemonic mechanism (inability to activate the Face Recognition Units (FRU) from the visual input) and a semantic mechanism (degradation of semantic/biographical information or deconnexion between FRU and this information). At the early stage of the disease, the patient could activate residual semantic information about individuals from their names, but after a 4-year course, he failed to do so. This worsening could be attributed to the extension of the degenerative lesions to the left temporal lobe. Familiar and unfamiliar faces triggered a marked feeling of knowing. False recognition concerned all the unfamiliar faces, and the patient claimed spontaneously that they corresponded to actors, but he could not provide any additional information about their specific identities. The coexistence of prosopagnosia and false recognition suggests the existence of different interconnected systems processing face recognition, one intended to identification of individuals, and the other producing the sense of familiarity. Dysfunctions at different stages of one or the other of these two processes could result in distortions in the feeling of knowing. CONCLUSION: From this case and others reported in literature, we propose to complete the classical model of face processing by adding a pathway linked to limbic system and frontal structures. This later pathway could normally emit signals for familiarity, essentially autonomic, in response to the familiar faces. These signals, primitively unconscious, secondly reach consciousness and are then integrated by a central supervisor system which evaluates and verifies identity-specific biographical information in order to make a decision about the sense of familiarity.

Aged↗

Matching of familiar faces and abstract patterns: behavioral and high-resolution ERP study.

Electrical scalp-recorded components peaking approximately 350-400 ms were reported to be sensitive to both repetition/priming effects and face familiarity. We studied the categorical matching of familiar faces and compared it to the matching of abstract patterns. Nineteen healthy volunteers participated in the study. Each trial began with one of the two cues (S1) followed by consecutive pictures (S2 and S3). Each picture was a photograph of a familiar face with a superimposed abstract dot pattern. One cue directed attention to compare faces and another to compare patterns. Participants were asked to respond by pressing different buttons. A 128-channel EEG was recorded. Analysis was done for the 600-ms window from the S3 onset, for correct performance. The face comparison was better and faster than the pattern comparison. In the Face task, match/mismatch differences were local in 200-250 ms and large and widespread in 270-550 ms. In the Pattern task, differences were found in 30-270 ms, while on longer latencies they were lesser than those in the Face task. Priming was observed in the Face task as shorter reaction times and reduced N400-like components (both in prefrontal and parietal regions) for the same items as compared to the different ones. In the Pattern task, the results were more controversial.

Adult↗

Event-related brain potentials to unfamiliar faces in explicit and implicit memory tasks.

The purpose of this study was to investigate electrophysiological correlates related to the recognition of repeated faces in the intact human by means of event-related brain potentials (ERPs). A group of young healthy adults performed a continuous face recognition task, in which 240 unfamiliar faces were flashed upon a computer screen with 80 of the faces being repetitions. The subjects had to classify faces as previously seen and previously unseen faces. The concomitantly recorded ERPs from 19 scalp sites revealed a more positive going waveform for the correctly classified repeated faces beginning at about 280 ms (old/new effect). The same subjects performed a similar task with visually presented concrete nouns as stimuli. The old/new effect in this task showed a similar distribution, amplitude and onset latency. It is thus concluded that the old/new effect is not specific to the materials to be memorized. In contrast, the old/new effect in an implicit face repetition experiment (with the detection of famous persons being the task) showed a different distribution. It is argued that the differential distribution might reflect the different requirements of the two tasks (explicit vs. implicit task). Recent interpretations of the old/new effects are discussed.

Adult↗

The spatiotemporal dynamics of the face inversion effect: a magneto- and electro-encephalographic study.

The neurophysiological basis of the face inversion effect was studied with magneto- and electro-encephalography in 10 normal subjects. Spatiotemporal analyses using dipole modeling was performed on combined evoked magneto and electro-encephalography data to hemifield presentation of upright and inverted faces and objects. Inferior temporal cortex, i.e. fusiform gyrus, and lateral temporal cortex near the superior temporal sulcus were activated simultaneously, but independently, at 140-200 ms post-stimulus to upright and inverted unfamiliar faces. Right hemisphere inferior temporal cortex and lateral temporal cortex were active in all subjects, and in the left hemisphere in half the subjects. Latencies to inverted relative to upright faces were longer in the right hemisphere, and shorter in the left hemisphere. For right hemifield stimulation ipsilateral activation delay was around 18-19 ms for both upright and inverted faces and was calculated from all 10 subjects. For left hemifield stimulation, and the data from 7 of 10 subjects, it was 22 and 29 ms to upright and inverted faces, respectively. In sum, the methods used in this study did not identify clear differences in anatomical location of activated regions to upright and inverted faces. We believe, however, that the differences in processing upright versus inverted faces are attributable to temporal processing differences rather than to processing of information by different brain regions.

Adult↗

A neural network reflecting decisions about human faces.

Anatomic structures have been linked to the mnemonic component of working memory, but the neural network underlying associated decision processes remains elusive. Here we present an event-related functional magnetic resonance imaging study that measured activity during the decision period of a delayed face recognition task. A double dissociation of activity between anterior cingulate cortex (ACC), and a network including left fusiform face area (FFA) and left dorsolateral prefrontal cortex (DLPFC), reflected whether a probe face matched the remembered face at the time of decision. Greater activity in the left FFA and left DLPFC correlated with probe faces that matched the remembered face; in contrast, activity in ACC was greater when the probe face did not match the remembered face. These results support a model where frontal regions act in concert with stimulus-specific temporal structures to make recognition decisions about visual stimuli.

Adult↗

Self-face recognition is affected by schizotypal personality traits.

The right cortical hemisphere appears to be important for processing self-face images and we have hypothesized that self-face processing is compromised in schizophrenia. As a way of testing this hypothesis, we investigated how reaction times to one's own face varied as a function of scores on the Schizotypal Personality Questionnaire (SPQ). Left-hand reaction times to self-face images were positively correlated to scores on the SPQ. In addition, people who scored 20 or below on the SPQ showed shorter reaction times to self-face images than stranger faces when responding with their left-hand, whereas those who scored 21 or above on the SPQ showed a left-hand disadvantage. These results imply that self-face processing in the right hemisphere is impaired in individuals with schizotypal traits. Our data are the first to show that traits associated with a schizophrenic spectrum disorder in a non-clinical population may compromise self-face recognition.

Adult↗

Representations in learning new faces: evidence from prosopagnosia.

We report the performance of a prosopagnosic patient on face learning tasks under different encoding instructions (i.e., levels of processing manipulations). R.J. performs at chance when given no encoding instructions or when given "shallow" encoding instruction to focus on facial features. By contrast, he performs relatively well with "deep" encoding instructions to rate faces in terms of personality traits or when provided with semantic and name information during the study phase. We propose that the improvement associated with deep encoding instructions may be related to the establishment of distinct visually derived and identity-specific semantic codes. The benefit associated with deep encoding in R.J., however, was found to be restricted to the specific view of the face presented at study and did not generalize to other views of the same face. These observations suggest that deep encoding instructions may enhance memory for concrete or pictorial representations of faces in patients with prosopagnosia, but that these patients cannot compensate for the inability to construct abstract structural codes that normally allow faces to be recognized from different orientations. We postulate further that R.J.'s poor performance on face learning tasks may be attributable to excessive reliance on a feature-based left hemisphere face processing system that operates primarily on view-specific representations.

Aged↗

A normed study of face recognition in autism and related disorders.

Although the interpretation of studies of face recognition in older children, adolescents, and adults with autism is complicated by the fact that participating samples and adopted methodologies vary significantly, there is nevertheless strong evidence indicating processing peculiarities even when task performance is not deficient. Much less is known about face recognition abilities in younger children with autism. This study employed a well-normed task of face recognition to measure this ability in 102 young children with autism, pervasive developmental disorder not otherwise specified (PDDNOS), and non-PDD disorders (mental retardation and language disorders) matched on chronological age and nonverbal mental age, and in a subsample of 51 children divided equally in the same three groups matched on chronological age and verbal mental age. There were pronounced deficits of face recognition in the autistic group relative to the other nonverbally matched and verbally matched groups. Performance on two comparison tasks did not reveal significant differences when verbal ability was adequately controlled. We concluded that young children with autism have face recognition deficits that cannot be attributed to overall cognitive abilities or task demands. In contrast to controls, there was a lower correlation between performance on face recognition and nonverbal intelligence, suggesting that in autism face recognition is less correlated with general cognitive capacity. Contrary to our expectation, children with PDDNOS did not show face recognition deficits.

Adult↗

Influence of task and input factors on hemispheric involvement in face processing.

Two experiments examined the respective role of the cerebral hemispheres in face perception and the nature of their contribution depending on task demands and on the spatial-frequency composition of the stimuli. Sixteen faces of members of the subjects' department were presented as stimuli, with men and women, and professors and nonprofessors being equally represented. In Experiment 1, high-resolution black-and-white photographs of faces were used in three reaction-time tasks: verbal identification, manual membership categorization, and manual male/female categorization, in a within-subject design. Identification and membership categorization were significantly better performed in right-visual-field presentations, whereas the male/female categorization yielded a nonsignificant left-visual-field superiority. In Experiment 2, two versions of the same faces were used: digitized low-pass (0 to 2 cycles/degree of visual angle) and digitized broad-pass (0 to 32 cycles/degree) faces. Broad-pass faces produced the same laterality pattern as in Experiment 1, while low-pass faces were better processed in left-visual-field presentations for all three tasks. The results suggest that the two hemispheres play a role in face perception, and their contribution may vary as a function of the task demands and of the spatial-frequency components of the incoming information.

Adult↗

Race as a visual feature: using visual search and perceptual discrimination tasks to understand face categories and the cross-race recognition deficit.

One of the most familiar empirical phenomena associated with face recognition is the cross-race (CR) recognition deficit whereby people have difficulty recognizing members of a race different from their own. Most researchers assume that the CR deficit is caused by failure to generalize perceptual encoding expertise from same-race (SR) faces to CR faces. However, this explanation ignores critical differences in the social cognitions and feature coding priorities associated with SR and CR faces. On the basis of data from visual search and perceptual discrimination tasks, it appears that the deficit occurs because people emphasize visual information specifying race at the expense of individuating information when recognizing CR faces. In particular, it is possible to observe a paradoxical improvement in both detection and perceptual discrimination accuracy for CR faces that is limited to those who recognize them poorly. These findings support a new explanation for the CR recognition deficit based on feature coding differences between CR and SR faces, and appear incompatible with similarity-based models of face categories.

Adult↗

Aging and memory for pictures of faces.

The hypothesis that pictorial aspects of face-recognition memory are lower in old age was tested in 2 studies. Young and elderly Ss viewed 48 face pictures, and then took a test containing identical copies of input faces, pictorially changed versions of input faces, and entirely new faces. Replicating prior findings, Experiment 1 showed that false recognitions of entirely new faces were higher among elderly Ss. However, there were no age differences in distinguishing identical from pictorially changed faces. Using a modified test, Experiment 2 showed that although the elderly Ss had good knowledge that changed faces were changed, they had relatively poor knowledge of how they were changed. There appears to be age differences in analytical matching of pictorial information against information in memory.

Adult↗

Hemispheric interactions during a face--word Stroop-analog task.

A Stroop-analog task with faces and words was developed to investigate intrahemispheric and interhemispheric Stroop effects (SEs). Lateralized faces and words were used in an attempt to invoke right- and left-hemispheric specialization, respectively. A prototypical male face, female face, and baby face and the corresponding words man, woman, and baby were presented as congruent or incongruent face-word pairs either to the same visual field (i.e., unilateral presentations) or to separate visual fields (i.e., bilateral presentations). Bidirectional SEs were found. Word distractors interfered with the identification of face targets, and, somewhat surprisingly, an even greater SE was obtained when words were the target and faces were ignored. Laterality effects were most pronounced for bilateral trials, whereby the SE was larger for right-hemisphere than for left-hemisphere target presentations, irrespective of type of target. This finding suggests that the left hemisphere is generally better shielded than the right from interhemispheric interference effects.

Adolescent↗

The effect of the cognitive interview on face identification accuracy: release from verbal overshadowing.

Three experiments tested the effect of verbal description on face identification accuracy. Based on verbal overshadowing research, it was predicted that enhancing verbal description of a face would reduce subsequent face identification accuracy. Experiment 1 tested and confirmed this hypothesis using the cognitive interview to enhance verbal description; face identification accuracy was reduced significantly following the cognitive interview, compared with a standard police interview. Experiments 2 and 3 tested and confirmed the hypothesis that verbal overshadowing would be reduced when a delay is inserted between verbal description and face identification, hence resulting in "release from verbal overshadowing." These results suggest that in the verbal overshadowing task, the verbal description does not overwrite the visually based representation of the face in memory but rather makes it less accessible at the time of face identification. The cognitive interview reduces face identification accuracy only when the identification follows description immediately--a rare situation in real criminal cases.

Adult↗

Stages of processing in face perception: an MEG study.

Here we used magnetoencephalography (MEG) to investigate stages of processing in face perception in humans. We found a face-selective MEG response occurring only 100 ms after stimulus onset (the 'M100'), 70 ms earlier than previously reported. Further, the amplitude of this M100 response was correlated with successful categorization of stimuli as faces, but not with successful recognition of individual faces, whereas the previously-described face-selective 'M170' response was correlated with both processes. These data suggest that face processing proceeds through two stages: an initial stage of face categorization, and a later stage at which the identity of the individual face is extracted.

Adolescent↗