Eifuku, Satoshi, Wania C. De Souza, Ryoi Tamura, Hisao Nishijo, and Taketoshi Ono. Neuronal correlates of face identification in the monkey anterior temporal cortical areas. J Neurophysiol 91: 358 -371, 2004; 10.1152/jn.00198.2003. To investigate the neuronal basis underlying face identification, the activity of face neurons in the anterior superior temporal sulcus (STS) and the anterior inferior temporal gyrus (ITG) of macaque monkeys was analyzed during their performance of a face-identification task. The face space was composed by the activities of face neurons during the face-identification task, based on a multidimensional scaling (MDS) method; the face space composed by the anterior STS neurons represented facial views, whereas that composed by the anterior ITG neurons represented facial identity. The temporal correlation between the behavioral reaction time of the animal and the latency of face-related neuronal responses was also analyzed. The response latency of some of the face neurons in the anterior ITG exhibited a significant correlation with the behavioral reaction time, whereas this correlation was not significant in the anterior STS. The correlation of the latency of face-related neuronal responses in the anterior ITG with the behavioral reaction time was not found to be attributed to the correlation between the response latency and the magnitude of the neuronal responses. The present results suggest that the anterior ITG is closely related to judgments of facial identity, and that the anterior STS is closely related to analyses of incoming perceptual information; face identification in monkeys might involve interactions between the two areas. I N T R O D U C T I O NThe identification of faces is a distinctive cognitive ability of primates and it plays an important role in social communication Bruce and Young 1998). Face neurons that respond selectively to the sight of faces were first identified in a region of the anterior temporal cortex in monkeys in the 1980s (Bruce et al. 1981;Perrett et al. 1982); such neurons have subsequently been identified in various areas of the monkey brain (Desimone et al. 1984;Harries and Perrett 1992;Hasselmo et al. 1989;Nakamura et al. 1992;Perrett et al. 1985;Scalaidhe et al. 1997;Yamane et al. 1988). In these previous studies, neuronal activity in response to faces was recorded in anesthetized immobilized monkeys or in alert monkeys that performed passive viewing or face-discrimination tasks. Some studies reported the existence of face neurons that might encode facial identity Sugase et al. 1999). However, it remains unclear how face neurons are related to the process of face identification; to determine this relationship in an animal model, we would need to have the animals perform face-identification tasks.Functional imaging (Halgren et al. 1999;Haxby et al. 1999;Hoffman and Haxby 2000;Ishai et al. 1999;Kanwisher et al. 1997) and evoked potential studies McCarthy et al. 1997McCarthy et al. , 1999Puce et al. 1999) of human brains revealed that multiple regions ...

. Differential characteristics of face neuron responses within the anterior superior temporal sulcus of macaques. J Neurophysiol 94: 1252-1266, 2005. doi:10.1152/jn.00949.2004. The anterior superior temporal sulcus (STS) of macaque monkeys is thought to be involved in the analysis of incoming perceptual information for face recognition or identification; face neurons in the anterior STS show tuning to facial views and/or gaze direction in the faces of others. Although it is well known that both the anatomical architecture and the connectivity differ between the rostral and caudal regions of the anterior STS, the functional heterogeneity of these regions is not well understood. We recorded the activity of face neurons in the anterior STS of macaque monkeys during the performance of a face identification task, and we compared the characteristics of face neuron responses in the caudal and rostral regions of the anterior STS. In the caudal region, facial views that elicited optimal responses were distributed among all views tested; the majority of face neurons responded symmetrically to right and left views. In contrast, the face neurons in the rostral region responded optimally to a single oblique view; right-left symmetry among the responses of these neurons was less evident. Modulation of the face neuron responses according to gaze direction was more evident in the rostral region. Some of the face neuron responses were specific to a certain combination of a particular facial view and a particular gaze direction, whereas others were associated with the relative spatial relationship between facial view and gaze direction. Taken together, these results indicated the existence of a functional heterogeneity within the anterior STS and suggested a plausible hierarchical organization of facial information processing.

The adequate interpretation of facial expressions of emotion is crucial for social functioning and human interaction. New methods are being applied, and a review of the methods that are used to evaluate facial emotion recognition is timely for the field. An extensive review was conducted using the Web of Science, PsycINFO, and PubMed databases. The following keywords were used to identify articles that were published within the past 20 years: emotion recognition, face, expression, and assessment. The initial search yielded 291 articles. After applying the exclusion criteria, 115 articles were included in this review. Articles were analyzed using 3 different approaches: (a) non-behavior-dependent methodologies (MRI and electroencephalography [EEG]), (b) behavioral instruments that were used to assess facial emotion recognition, and (c) instruments or methods that were used to assess facial recognition impairment in health conditions. The behavioral instruments were further subdivided into 7 groups. Static human face stimuli were the most frequently used method, although there are some criticisms concerning the ecological validity of these types of stimuli. Nonvalidated instruments were also commonly used, especially in psychopathological studies. Computer-based morphing has been used to develop new visual stimuli, and brief videos are also being applied. Drawings, which may have lower validity, were often used for assessment in children. Research that uses functional and structural MRI or EEG as methodological alternatives has increased in the last decade. This is a rapidly changing field, and more studies are needed to compare methodologies that are used to explore impairments in facial emotion recognition.

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Significant advances in the understanding of processes involved in face perception have been achieved. This study aims to review the literature of face perception in neurobiological and social contexts. The review focused on the mechanisms of mediation of face perception by neural substrates, and discussed some of the social signals provided by faces. We showed that psychological, neurophysiological and neuroimaging studies have demonstrated that a dedicated neural system for face perception exists in primates, which includes the fusiform face area (FFA), anterior superior temporal sulcus (STS) and anterior inferior temporal gyrus (ITG). But it remains to be understood how the integration of face perception occurs in the neurobiological context and in the social context.

To investigate the neural representations of faces in primates, particularly in relation to their personal familiarity or unfamiliarity, neuronal activities were chronically recorded from the ventral portion of the anterior inferior temporal cortex (AITv) of macaque monkeys during the performance of a facial identification task using either personally familiar or unfamiliar faces as stimuli. By calculating the correlation coefficients between neuronal responses to the faces for all possible pairs of faces given in the task and then using the coefficients as neuronal population-based similarity measures between the faces in pairs, we analyzed the similarity/dissimilarity relationship between the faces, which were potentially represented by the activities of a population of the face-responsive neurons recorded in the area AITv. The results showed that, for personally familiar faces, different identities were represented by different patterns of activities of the population of AITv neurons irrespective of the view (e.g., front, 90° left, etc.), while different views were not represented independently of their facial identities, which was consistent with our previous report. In the case of personally unfamiliar faces, the faces possessing different identities but presented in the same frontal view were represented as similar, which contrasts with the results for personally familiar faces. These results, taken together, outline the neuronal representations of personally familiar and unfamiliar faces in the AITv neuronal population.

ResumoA literatura vem discutindo acerca da percepção de emoções faciais evidentes em idosos com Doença de Alzheimer (DA). Alguns autores sugerem que os défi cits apresentados são decorrentes de problemas visuoespaciais; outros sugerem que são por difi culdades no processamento das emoções; e há os que defendem que esse défi cit perceptivo é secundário à evolução da demência. Esta pesquisa buscou investigar os aspectos neuropsicológicos da expressão emocional facial, por meio da aplicação da Escala de Inteligência Wechsler para Adultos-III (WAIS-III) e de um programa de computador desenvolvido pelo Laboratório de Psicobiologia denominado Teste de Percepção de Expressões Faciais (TEPEF), que avalia a percepção de faces emocionais em idosos. Os resultados sugerem que o WAIS-III foi sensível para a diferenciação entre os grupos experimental e controle, mas apresentou pouca especifi cidade. O TEPEF apresentou consistência para avaliar as expressões faciais de alegria, tristeza, nojo, surpresa e raiva. Além disso, ele mostrou que a percepção de alegria em idosos com DA em fase moderada está relativamente preservada. Conclui-se, portanto, que os prejuízos relacionam-se às emoções negativas evidenciadas pela percepção das faces emocionais, demandando supervisão continuada para os idosos com essas alterações. Palavras-chave: Doença de Alzheimer, face, percepção visual. AbstractLiterature has been discussing the perception of emotional facial expressions in elderly suffering from Alzheimer's Disease (AD). Some authors suggest that defi cits occur due to visuospatial problems; others suggest that the diffi culty is related to emotional processing; still others argue that this perceptive defi cit is secondary to dementia evolution. This study aimed to investigate the neuropsychological aspects of the perception of facial emotional expression by applying the Wechsler Adult Intelligence Scale-III (WAIS-III) test, as well as a software named Perception Test of Facial Emotional Expressions (TEPEF), which analyzes the perception of emotional faces by the elderly. The results suggest that WAIS-III was sensible in discriminating the differences between experimental and control groups, but presented little specifi city. The TEPEF presented consistency to evaluate facial expressions of happiness, sadness, disgust, surprise and anger. Furthermore, it showed that the perception of happiness in the elderly with mild AD is relatively preserved. The expressions more easily perceived -such as happiness and sadness -had correlations with few WAIS-III subtests. Therefore, the study concluded that the losses are related to negative emotions evidenced by the perception of emotional faces, which requires continued supervision for the elderly with these changes.

Down syndrome (DS) is one of the most common chromosomal abnormalities. Delays in cognitive development are found in the first years of life. As years pass, it may turn into intellectual deficiencies that unfold into several aspects, including difficulty recognizing emotional facial expressions. The present study investigated the recognition of six universal facial emotional expressions in a population of children aged 6-11 years who were divided into two groups: DS group and typically developing children (TDC) group. We used the Perception Test of Facial Emotional Expressions (Teste de Percepção de Emoções Faciais; TEPEF) and Wechsler Intelligence Scale for Children (WISC-III) and found that children with DS presented alterations in the recognition of expressions of disgust, surprise, and fear, whereas the recognition of happiness, sadness, and anger was maintained at a level comparable to the TDC group. Participants with DS presented significant positive correlations between sadness and Picture completion, Mazes, Arithmetic, Vocabulary, Digits, Verbal IQ, Verbal Comprehension Index, and Working Memory Index. All other facial expressions showed significant negative correlations with the Intelligence Quotient and WISC-III factorial index subtests. Absence of correlations was found among the TEPEF's six facial expressions and Information, Coding, Symbols, and Working Memory Index. The contribution of this study is related to understanding the characteristics of the recognition of facial emotions in children with DS, an important component of social relationships with their peers, schools, and families.