Processing Of Facial Information Research Articles

Neuronal responses to face-like and facial stimuli in the monkey superior colliculus

The superficial layers of the superior colliculus (sSC) appear to function as a subcortical visual pathway that bypasses the striate cortex for the rapid processing of coarse facial information. We investigated the responses of neurons in the monkey sSC during a delayed non-matching-to-sample (DNMS) task in which monkeys were required to discriminate among five categories of visual stimuli [photos of faces with different gaze directions, line drawings of faces, face-like patterns (three dark blobs on a bright oval), eye-like patterns, and simple geometric patterns]. Of the 605 sSC neurons recorded, 216 neurons responded to the visual stimuli. Among the stimuli, face-like patterns elicited responses with the shortest latencies. Low-pass filtering of the images did not influence the responses. However, scrambling of the images increased the responses in the late phase, and this was consistent with a feedback influence from upstream areas. A multidimensional scaling (MDS) analysis of the population data indicated that the sSC neurons could separately encode face-like patterns during the first 25-ms period after stimulus onset, and stimulus categorization developed in the next three 25-ms periods. The amount of stimulus information conveyed by the sSC neurons and the number of stimulus-differentiating neurons were consistently higher during the 2nd to 4th 25-ms periods than during the first 25-ms period. These results suggested that population activity of the sSC neurons preferentially filtered face-like patterns with short latencies to allow for the rapid processing of coarse facial information and developed categorization of the stimuli in later phases through feedback from upstream areas.

Autistic traits predict weaker visual influence in the McGurk effect

The McGurk effect is a well-known illustration that demonstrates the influence of visual information to hearing in speech perception. Individuals with Autism Spectrum Disorder (ASD) show weaker visual influence in the McGurk effect. This might result from abnormalities in the processing of facial information. In this study, we examined the effect of face perception (holistic vs part-based processing) and the individual differences in the McGurk effect among 48 healthy students. The McGurk tasks were tested under 3 presentation conditions of visual images: mouth only, mouth and eyes, and face. The result revealed that individuals with higher scores for autistic traits respectively might report less visually captured responses in all conditions. This suggests that autistic traits might be related to “weak central coherence” in speech perception rather than abnormalities in face perception.

Feature Tracking and Expression Recognition of Face Using Dynamic Bayesian Network

The human face plays a central role in social interaction, hence it is not surprising that facial information processing is an important and highly active subfield of cognitive science research. The face is a complex stimulus displaying information about identity, age, gender, as well as emotional and attention state. Here we consider the problem of extracting information about emotional state (facial expression) from single images. Due to the difficulty of obtaining controlled video sequences of standard facial expressions, many psychological and neurophysiologic studies of facial expression processing have used single image motivations. In proposed system, in contrast to the mainstream approaches, we are trying to build a probabilistic model based on the Dynamic Bayesian Network (DBN) to capture the facial interactions at different levels. Hence the proposed system deal with the identification of facial expression on the image captured through camera.

The neural representation of faces and bodies in motion and at rest

The neural organization of person processing relies on brain regions functionally selective for faces or bodies, with a subset of these regions preferring moving stimuli. Although the response properties of the individual areas are well established, less is known about the neural response to a whole person in a natural environment. Targeting an area of cortex that spans multiple functionally-selective face and body regions, we examined the relationship among neural activity patterns elicited in response to faces, bodies, and people in static and moving displays. When both stimuli were static or moving, pattern classification analyses indicated highly discriminable responses to faces, bodies, and whole people. Neural discrimination transferred in both directions between representations created from moving or static stimuli. It transferred also to stimuli experienced across static and dynamic presentations (one static and the other dynamic). In both transfer cases, however, discrimination accuracy decreased relative to the case where the representations were both created and tested with static or moving forms. Next, we examined the relative contribution of activity pattern and response magnitude to discrimination by comparing classifiers that operated with magnitude-normalized scans with classifiers that retained pattern and magnitude information. When both stimuli were moving or static, response magnitude contributed to classification, but the spatially distributed activity pattern accounted for most of the discrimination. Across static and moving presentations, activity pattern accounted completely for the discriminability of neural responses to faces, bodies, and people, with no contribution from response magnitude. Combined, the results indicate redundant and flexible access to person-based shape codes from moving and static presentations. The transfer of shape information across presentation types that preferentially access dorsal and ventral visual processing streams indicates that a common shape code may ground functional divisions in the processing of face and body information.

Assessing the Utility of a Virtual Environment for Enhancing Facial Affect Recognition in Adolescents with Autism

Teenagers with autism spectrum disorder (ASD) and age-matched controls participated in a dynamic facial affect recognition task within a virtual reality (VR) environment. Participants identified the emotion of a facial expression displayed at varied levels of intensity by a computer generated avatar. The system assessed performance (i.e., accuracy, confidence ratings, response latency, and stimulus discrimination) as well as how participants used their gaze to process facial information using an eye tracker. Participants in both groups were similarly accurate at basic facial affect recognition at varied levels of intensity. Despite similar performance characteristics, ASD participants endorsed lower confidence in their responses and substantial variation in gaze patterns in absence of perceptual discrimination deficits. These results add support to the hypothesis that deficits in emotion and face recognition for individuals with ASD are related to fundamental differences in information processing. We discuss implications of this finding in a VR environment with regards to potential future applications and paradigms targeting not just enhanced performance, but enhanced social information processing within intelligent systems capable of adaptation to individual processing differences.

自闭症患者面部信息加工的研究简述

自闭症患者面部信息加工的研究简述

Noninvasive detection of face perception characteristics in children with autism spectrum disorders

AbstractChildren with autism spectrum disorders (ASD) have delayed or deviant social interaction and communication skills. Recent neuroimaging studies have corroborated unique behaviors and patterns of facial information processing in children with ASD, such as less attention toward faces, atypical gaze pattern and face inversion effect, and difficulty in understanding facial expressions and identification of faces. The findings suggest that these specific face recognition characteristics are the result of detail‐focused processing and/or a distinctive cognitive style in dealing with visual inputs. This paper reviews our recent work evaluating social perception of faces using noninvasive neuroimaging techniques in children with ASD.

‘Faceness’ and affectivity: Evidence for genetic contributions to distinct components of electrocortical response to human faces

The ability to recognize a variety of different human faces is undoubtedly one of the most important and impressive functions of the human perceptual system. Neuroimaging studies have revealed multiple brain regions (including the FFA, STS, OFA) and electrophysiological studies have identified differing brain event-related potential (ERP) components (e.g., N170, P200) possibly related to distinct types of face information processing. To evaluate the heritability of ERP components associated with face processing, including N170, P200, and LPP, we examined ERP responses to fearful and neutral face stimuli in monozygotic (MZ) and dizygotic (DZ) twins. Concordance levels for early brain response indices of face processing (N170, P200) were found to be stronger for MZ than DZ twins, providing evidence of a heritable basis to each. These findings support the idea that certain key neural mechanisms for face processing are genetically coded. Implications for understanding individual differences in recognition of facial identity and the emotional content of faces are discussed.

Dissociable neural correlates of item and context retrieval in the medial temporal lobes

Although it is generally accepted that the medial temporal lobe (MTL) is critical for episodic memory, the contributions of cortical regions in the MTL, such as the perirhinal (PRc) and parahippocampal (PHc) cortices, remain unresolved. Recent studies have asserted that the PRc supports the processing of object and face information, whereas the PHc supports the processing of scene information. These findings have been used to characterize the PRc and PHc as being important for the memory of objects and scenes, respectively. However, these results are also consistent with the idea that these MTL regions are critical for the memory of stimuli that are processed as either items or contexts. It has been difficult to differentiate between these two accounts given that in most studies, item and context are operationalized as different types of memoranda (e.g., memory for objects compared to memory for background scenes). Here, we tested the extent to which different MTL regions are involved in the retrieval of item or context information when the material type is held constant. Participants encoded pairs of fractal images and were oriented to encode one fractal as an item and the other as a context. At test, they were cued with previously studied item or context fractals and asked to retrieve the corresponding associate. Results indicated that on test trials, PRc activity was increased during recall of fractals that were encoded as items, whereas PHc activity was greater during recall of fractals that were encoded as contexts. These results provide direct evidence that, even when stimulus type is held constant, the PRc and PHc are preferentially involved in supporting memory for item and context information, respectively.

Dynamic connectivity laterality of the amygdala under negative stimulus in depression: A MEG study

Depression is a mental disorder characterized by emotional and cognitive dysfunction, which is related to the abnormal activity in brain regions involving emotion processing such as amygdala (AMYG). The laterality of AMYG during emotional information processing has always been a controversial issue in any depression study, however, the dynamic characteristic of laterality in the AMYG has been ignored. In this paper, we proposed to explore the time-varying functional coupling between the anterior cingulate cortex (ACC) and the bilateral AMYG in the time–frequency domain. As a result, an emotional facial expression paradigm was undertaken in this study. Using magnetoencephalogram (MEG) data acquired from 16 patients with major depression disorder and 16 matched healthy controls, we calculated the wavelet coherence. The research led to the conclusion that, after sad facial stimuli, the ACC–bilateral AMYG connectivity in depressive patients showed a significant decrease in the beta band during the first 100ms. In addition, the ACC–left AMYG connectivity led to a significant increase in the gamma band around 400ms and in beta band around 700ms. Our work suggests a lack of sufficient inhibition of the ACC on the bilateral AMYG in the early period and the lateralized dysregulation of the ACC on the left AMYG in late period during the sad facial information processing task. We hypothesized that the clinical manifestations of depression may partly result from it.

Coalescence of dominance motivation and responses to facial anger in resting-state and event-related electrophysiology

People vary in their proneness to dominate as a function of their motivation to fulfill their need for reward and social status. Recent research suggests that in humans dominant individuals respond vigilantly to angry faces, whereas non-dominant individuals rapidly signal submission. Dominance motivation has been suggested to reside in asymmetrical patterns of cortical and subcortical processing. The ratio between δ and β band oscillations has been proposed as a proxy for this asymmetry, which we here aimed to map onto individual patterns of the event-related potentials (N170) as well as behavioral responses to facial anger in the context of dominance motivation. Results show that dominance motivation indeed predicts increased δ in the δ/β asymmetry; a pattern that further translates into behavioral vigilance as well as attenuation of the event-related response to angry faces. The present data are interpreted to suggest that dominance motivation is related to increased subcortical and decreased cortical processing, and that this translates into increased vigilance in dominance challenges. This motivational state is further characterized by less detailed processing of facial information as reflected in the attenuation of N170 amplitude.

Recognition of Facial Expressions and Prosodic Cues with Graded Emotional Intensities in Adults with Asperger Syndrome

This study investigated the ability of adults with Asperger syndrome to recognize emotional categories of facial expressions and emotional prosodies with graded emotional intensities. The individuals with Asperger syndrome showed poorer recognition performance for angry and sad expressions from both facial and vocal information. The group difference in facial expression recognition was prominent for stimuli with low or intermediate emotional intensities. In contrast to this, the individuals with Asperger syndrome exhibited lower recognition accuracy than typically-developed controls mainly for emotional prosody with high emotional intensity. In facial expression recognition, Asperger and control groups showed an inversion effect for all categories. The magnitude of this effect was less in the Asperger group for angry and sad expressions, presumably attributable to reduced recruitment of the configural mode of face processing. The individuals with Asperger syndrome outperformed the control participants in recognizing inverted sad expressions, indicating enhanced processing of local facial information representing sad emotion. These results suggest that the adults with Asperger syndrome rely on modality-specific strategies in emotion recognition from facial expression and prosodic information.

Intermixed structure of voxels with different hemispheric characteristics in the fusiform face area

The fusiform face area, a high-level visual area, is pivotal in processing facial information. This area receives inputs from the left and right visual fields unlike the primary visual area, which only receives inputs from its contralateral visual field. Response of the fusiform face area to ipsilateral stimulation depends on the signals crossing over at the corpus callosum. We investigated the distribution of voxel-wise activation to determine whether ipsilateral-dominant voxels exist in the fusiform face area using high spatial resolution functional MRI at 7 T. We further examined the possible functional differences between ipsilateral-dominant and contralateral-dominant voxels. By unilateral visual field stimulation, we detected ipsilateral-dominant voxels in the right fusiform face area. Their distribution was spatially heterogeneous. We tested upright and inverted facial stimulation confined to unilateral visual fields and found that these ipsilateral-dominant voxels had a different functional nature from contralateral-dominant voxels.

Do neural correlates of face expertise vary with task demands? Event-related potential correlates of own- and other-race face inversion

We are typically more accurate at remembering own- than other-race faces. This “own-race bias” has been suggested to result from enhanced expertise with and more efficient perceptual processing of own-race than other-race faces. In line with this idea, the N170, an event-related potential correlate of face perception, has been repeatedly found to be larger for other-race faces. Other studies, however, found no difference in N170 amplitude for faces from diverse ethnic groups. The present study tested whether these seemingly incongruent findings can be explained by varying task demands. European participants were presented with upright and inverted European and Asian faces (as well as European and Asian houses), and asked to either indicate the ethnicity or the orientation of the stimuli. Larger N170s for other-race faces were observed in the ethnicity but not in the orientation task, suggesting that the necessity to process facial category information is a minimum prerequisite for the occurrence of the effect. In addition, N170 inversion effects, with larger amplitudes for inverted relative to upright stimuli, were more pronounced for own- relative to other-race faces in both tasks. Overall, the present findings suggest that the occurrence of ethnicity effects in N170 for upright faces depends on the amount of facial detail required for the task at hand. At the same time, the larger inversion effects for own- than other-race faces occur independent of task and may reflect the fine-tuning of perceptual processing to faces of maximum expertise.

Neuronal responses to face‐like stimuli in the monkey pulvinar

The pulvinar nuclei appear to function as the subcortical visual pathway that bypasses the striate cortex, rapidly processing coarse facial information. We investigated responses from monkey pulvinar neurons during a delayed non-matching-to-sample task, in which monkeys were required to discriminate five categories of visual stimuli [photos of faces with different gaze directions, line drawings of faces, face-like patterns (three dark blobs on a bright oval), eye-like patterns and simple geometric patterns]. Of 401 neurons recorded, 165 neurons responded differentially to the visual stimuli. These visual responses were suppressed by scrambling the images. Although these neurons exhibited a broad response latency distribution, face-like patterns elicited responses with the shortest latencies (approximately 50 ms). Multidimensional scaling analysis indicated that the pulvinar neurons could specifically encode face-like patterns during the first 50-ms period after stimulus onset and classify the stimuli into one of the five different categories during the next 50-ms period. The amount of stimulus information conveyed by the pulvinar neurons and the number of stimulus-differentiating neurons were consistently higher during the second 50-ms period than during the first 50-ms period. These results suggest that responsiveness to face-like patterns during the first 50-ms period might be attributed to ascending inputs from the superior colliculus or the retina, while responsiveness to the five different stimulus categories during the second 50-ms period might be mediated by descending inputs from cortical regions. These findings provide neurophysiological evidence for pulvinar involvement in social cognition and, specifically, rapid coarse facial information processing.

N170 response to facial expressions is modulated by the affective congruency between the emotional expression and preceding affective picture

Does contextual affective information influence the processing of facial expressions already at the relatively early stages of face processing? We measured event-related brain potentials to happy and sad facial expressions primed by preceding pictures with affectively positive and negative scenes. The face-sensitive N170 response amplitudes showed a clear affective priming effect: N170 amplitudes to happy faces were larger when presented after positive vs. negative primes, whereas the N170 amplitudes to sad faces were larger when presented after negative vs. positive primes. Priming effects were also observed on later brain responses. The results support an early integration in processing of contextual and facial affective information. The results also provide neurophysiological support for theories suggesting that behavioral affective priming effects are based, at least in part, on facilitation of encoding of incoming affective information.

Neural mechanism of dynamic responses of neurons in inferior temporal cortex in face perception

Understanding the neural mechanisms of object and face recognition is one of the fundamental challenges of visual neuroscience. The neurons in inferior temporal (IT) cortex have been reported to exhibit dynamic responses to face stimuli. However, little is known about how the dynamic properties of IT neurons emerge in the face information processing. To address this issue, we made a model of IT cortex, which performs face perception via an interaction between different IT networks. The model was based on the face information processed by three resolution maps in early visual areas. The network model of IT cortex consists of four kinds of networks, in which the information about a whole face is combined with the information about its face parts and their arrangements. We show here that the learning of face stimuli makes the functional connections between these IT networks, causing a high spike correlation of IT neuron pairs. A dynamic property of subthreshold membrane potential of IT neuron, produced by Hodgkin-Huxley model, enables the coordination of temporal information without changing the firing rate, providing the basis of the mechanism underlying face perception. We show also that the hierarchical processing of face information allows IT cortex to perform a "coarse-to-fine" processing of face information. The results presented here seem to be compatible with experimental data about dynamic properties of IT neurons.

The face-selective N170 component is modulated by facial color

Faces play an important role in social interaction by conveying information and emotion. Of the various components of the face, color particularly provides important clues with regard to perception of age, sex, health status, and attractiveness. In event-related potential (ERP) studies, the N170 component has been identified as face-selective. To determine the effect of color on face processing, we investigated the modulation of N170 by facial color. We recorded ERPs while subjects viewed facial color stimuli at 8 hue angles, which were generated by rotating the original facial color distribution around the white point by 45° for each human face. Responses to facial color were localized to the left, but not to the right hemisphere. N170 amplitudes gradually increased in proportion to the increase in hue angle from the natural-colored face. This suggests that N170 amplitude in the left hemisphere reflects processing of facial color information.

Higher sensitivity for low spatial frequency expressions in social anxiety: Evident in indirect but not direct tasks?

We tested whether socially anxious individuals perform better in processing facial information with low spatial frequencies (LSFs). For this, we presented socially anxious and nonanxious participants with hybrid face stimuli that contained independent facial expressions in high (HSF) and LSF bands. In two tasks, participants either rated the images according to "angriness" or had to learn how hybrid facial expressions predicted the location of an upcoming target. We found mostly additive effects of LSF and HSF information in the rating task for both groups. In contrast, socially anxious participants showed better prediction performance for LSF expressions in the implicit learning task. We conclude that socially anxious participants are more sensitive to facial information within LSFs, but this higher sensitivity may become mostly evident in indirect tasks.

Differing Processing Abilities for Specific Face Properties in Mid-Childhood and Adulthood

The ability to process facial information is vital for social interactions. Previous research has shown that mature face processing depends on the extraction of featural and configural face information. It has been also shown that the acquisition of these processing skills is prolonged in children. The order in which different face properties are processed is currently less understood. Namely, while some research has supported a parallel-route model which groups different properties according to their variability, other studies have shown that specific invariant properties, such as facial identity, can serve as a reference frame for interpreting more dynamic aspects, such as facial expression or eye gaze direction. The current study tested a different approach, which proposes that face property processing varies with task requirements. Sixteen adults did a same-different task where the second face could differ from the first in the identity, expression, or gaze, or any combination of those. We found that reaction times increased and accuracy rates decreased when the identity was repeated, suggesting that changes in facial identity were the most salient ones. Finally, we tested two groups of 7-to 8- and 10- to 11-year-old children and found lower accuracy rates for those face properties that rely in particular on configural information processing strategies. This suggests that while overall, face processing strategies are adult-like from 7 years of age, the processing of specific face properties develops continuously throughout mid-childhood.