Non-face Processing Research Articles

Special Patterns of Dynamic Brain Networks Discriminate Between Face and Non-face Processing: A Single-Trial EEG Study.

Face processing is a spatiotemporal dynamic process involving widely distributed and closely connected brain regions. Although previous studies have examined the topological differences in brain networks between face and non-face processing, the time-varying patterns at different processing stages have not been fully characterized. In this study, dynamic brain networks were used to explore the mechanism of face processing in human brain. We constructed a set of brain networks based on consecutive short EEG segments recorded during face and non-face (ketch) processing respectively, and analyzed the topological characteristic of these brain networks by graph theory. We found that the topological differences of the backbone of original brain networks (the minimum spanning tree, MST) between face and ketch processing changed dynamically. Specifically, during face processing, the MST was more line-like over alpha band in 0–100 ms time window after stimuli onset, and more star-like over theta and alpha bands in 100–200 and 200–300 ms time windows. The results indicated that the brain network was more efficient for information transfer and exchange during face processing compared with non-face processing. In the MST, the nodes with significant differences of betweenness centrality and degree were mainly located in the left frontal area and ventral visual pathway, which were involved in the face-related regions. In addition, the special MST patterns can discriminate between face and ketch processing by an accuracy of 93.39%. Our results suggested that special MST structures of dynamic brain networks reflected the potential mechanism of face processing in human brain.

Reduced Reliance on Optimal Facial Information for Identity Recognition in Autism Spectrum Disorder

Previous research into face processing in autism spectrum disorder (ASD) has revealed atypical biases toward particular facial information during identity recognition. Specifically, a focus on features (or high spatial frequencies [HSFs]) has been reported for both face and nonface processing in ASD. The current study investigated the development of spatial frequency biases in face recognition in children and adolescents with and without ASD, using nonverbal mental age to assess changes in biases over developmental time. Using this measure, the control group showed a gradual specialization over time toward middle spatial frequencies (MSFs), which are thought to provide the optimal information for face recognition in adults. By contrast, individuals with ASD did not show a bias to one spatial frequency band at any stage of development. These data suggest that the “midband bias” emerges through increasing face-specific experience and that atypical face recognition performance may be related to reduced specialization toward optimal spatial frequencies in ASD.

To the trained eye: perceptual expertise alters visual processing.

Perceptual expertise refers to learning that is specific to a domain, that transfers to new items within the trained domain, and that leads to automatic processing in the sense that expertise effects can be measured across a variety of tasks. It can be argued that most of us possess some degree of perceptual expertise in a least one, if not several domains, thereby giving the study of perceptual expertise broad application. Some object categories may in fact be objects of perceptual expertise to the majority of people: Faces appear to be one such example. Thus, the use of face stimuli, or the comparison of face and object perception, can be a powerful way to ask whether a given process is influenced by perceptual expertise. Here, we emphasize one characteristic way that face processing appears to differ from nonface processing: that is, the degree to which they recruit a "holistic" rather than a "featural" perceptual strategy. This review brings evidence that expertise influences perceptual processing together with recent findings that the capacity of visual short-term memory is greater in perceptual experts and explores the relationship between the two.

The roles of visual expertise and visual input in the face inversion effect: Behavioral and neurocomputational evidence

Research has shown that inverting faces significantly disrupts the processing of configural information, leading to a face inversion effect. We recently used a contextual priming technique to show that the presence or absence of the face inversion effect can be determined via the top–down activation of face versus non-face processing systems [Ge, L., Wang, Z., McCleery, J., & Lee, K. (2006). Activation of face expertise and the inversion effect. Psychological Science, 17(1), 12–16]. In the current study, we replicate these findings using the same technique but under different conditions. We then extend these findings through the application of a neural network model of face and Chinese character expertise systems. Results provide support for the hypothesis that a specialized face expertise system develops through extensive training of the visual system with upright faces, and that top–down mechanisms are capable of influencing when this face expertise system is engaged.

A Bottleneck in Face Identification

There is evidence that face processing is capacity-limited in distractor interference tasks and in tasks requiring overt recognition memory. We examined whether capacity limits for faces can be observed with a more sensitive measure of visual processing, by measuring repetition priming of flanker faces that were presented alongside a face or a nonface target. In Experiment 1, we found identity priming for face flankers, by measuring repetition priming across a change in image, during task-relevant nonface processing, but not during the processing of a concurrently-presented face target. Experiment 2 showed perceptual priming of the flanker faces, across identical images at prime and test, when they were presented alongside a face target. In a third Experiment, all of these effects were replicated by measuring identity priming and perceptual priming within the same task. Overall, these results imply that face processing is capacity limited, such that only a single face can be identified at one time. Merely attending to a target face appears sufficient to trigger these capacity limits, thereby extinguishing identification of a second face in the display, although our results demonstrate that the additional face remains at least subject to superficial image processing.

Face processing in schizophrenia: defining the deficit.

Abnormalities of face affect naming and face recognition occur in schizophrenia but it is not clear whether the deficits reflect wider underlying impairments of perception, memory, language or executive function. Twenty-six patients with schizophrenia were compared with 23 healthy volunteers on neuropsychological tests and tests of face and affect processing. Face and non-face tests were compared at four levels of processing: visuo-spatial perception, recognition memory, language and naming, and executive function. We examined relationships with drug dose, duration of illness and pre-morbid and current IQ. Patients and controls did not differ in estimated pre-morbid IQ but current IQ was 12 points lower in patients. At each level of processing there were correlated deficits of face and non-face processing in the patients that were mostly independent of IQ decline. Impaired face and non-face visuo-spatial function and recognition performance were generally correlated with drug dose. Impairments in naming face emotions were correlated with other non-face naming tasks independently of drug dose. Patients performed less well than controls in classifying faces by emotion while ignoring identity and this was associated with poorer performance in Wisconsin Card Sorting. The pattern of results suggests that deficits in face processing reflect three wider neuropsychological impairments: a drug-related impairment of visual imagery, and disease-related impairments of semantic retrieval and executive function.