Investigating the Influence of Autism Spectrum Traits on Face Processing Mechanisms in Developmental Prosopagnosia.

Autism traits are common exclusionary criteria in developmental prosopagnosia (DP) studies. We investigated whether autism traits produce qualitatively different face processing in 43 DPs with high vs. low autism quotient (AQ) scores. Compared to controls (n = 27), face memory and perception were similarly deficient in the high- and low-AQ DPs, with the high-AQ DP group additionally showing deficient face emotion recognition. Task-based fMRI revealed reduced occipito-temporal face selectivity in both groups, with high-AQ DPs additionally demonstrating decreased posterior superior temporal sulcus selectivity. Resting-state fMRI showed similar reduced face-selective network connectivity in both DP groups compared with controls. Together, this demonstrates that high- and low-AQ DP groups have very similar face processing deficits, with additional facial emotion deficits in high-AQ DPs.

Investigating the perception of face identity in adults on the autism spectrum using behavioural and electrophysiological measures.

In the present study, we investigated face processing in individuals with self-reported Autism Spectrum Disorder (ASD, n = 16) and typically developing control participants (n = 16) using behavioural and electrophysiological measures. As a measure of their face memory, we administered the Cambridge Face Memory Test to participants in the ASD group. The results showed that the scores of the ASD participants were reliably below the age- and gender-matched norms of neurotypical individuals. To measure brain responses to faces, we used the fast periodic visual stimulation method, presenting photographs of a same-identity face (i.e., base face) at a constant frequency of 6 Hz (F) interleaved with different-identity faces (i.e., the oddball faces) presented at 1.2 Hz. The 6 Hz presentation of the base face and 1.2 Hz presentation of the oddball face elicited periodic brain responses corresponding to face detection and face individuation processes, respectively. Participants viewed four blocks of upright faces and four blocks of inverted faces. The results showed an enhanced EEG response to upright base faces at 6 Hz frequency and its harmonics compared to inverted faces, and the response was most focal over medial occipital channels. An enhanced response was found to upright oddball faces at 1.2 Hz and its harmonics compared to the inverted faces, and the response was centred over occipito-temporal channels in the right hemisphere. Critically, no differences or interactions were found between the ASD and typically developing groups in the responses to either the 6 Hz base faces or the 1.2 oddball faces. These results suggest that in individuals with ASD, the earlier stage of face perception, as measured by the fast periodic visual stimulation paradigm, can be dissociated from the later memory stage of face processing, as assessed by the Cambridge Face Memory Test.

The perception and identification of facial emotions in individuals with autism spectrum disorders using the Let's Face It! Emotion Skills Battery.

BACKGROUND: Although impaired social-emotional ability is a hallmark of autism spectrum disorder (ASD), the perceptual skills and mediating strategies contributing to the social deficits of autism are not well understood. A perceptual skill that is fundamental to effective social communication is the ability to accurately perceive and interpret facial emotions. To evaluate the expression processing of participants with ASD, we designed the Let's Face It! Emotion Skills Battery (LFI! Battery), a computer-based assessment composed of three subscales measuring verbal and perceptual skills implicated in the recognition of facial emotions. METHODS: We administered the LFI! Battery to groups of participants with ASD and typically developing control (TDC) participants that were matched for age and IQ. RESULTS: On the Name Game labeling task, participants with ASD (N = 68) performed on par with TDC individuals (N = 66) in their ability to name the facial emotions of happy, sad, disgust and surprise and were only impaired in their ability to identify the angry expression. On the Matchmaker Expression task that measures the recognition of facial emotions across different facial identities, the ASD participants (N = 66) performed reliably worse than TDC participants (N = 67) on the emotions of happy, sad, disgust, frighten and angry. In the Parts-Wholes test of perceptual strategies of expression, the TDC participants (N = 67) displayed more holistic encoding for the eyes than the mouths in expressive faces whereas ASD participants (N = 66) exhibited the reverse pattern of holistic recognition for the mouth and analytic recognition of the eyes. CONCLUSION: In summary, findings from the LFI! Battery show that participants with ASD were able to label the basic facial emotions (with the exception of angry expression) on par with age- and IQ-matched TDC participants. However, participants with ASD were impaired in their ability to generalize facial emotions across different identities and showed a tendency to recognize the mouth feature holistically and the eyes as isolated parts.

Mixed emotions: holistic and analytic perception of facial expressions.

In the face literature, it is debated whether the identification of facial expressions requires holistic (i.e., whole face) or analytic (i.e., parts-based) information. In this study, happy and angry composite expressions were created in which the top and bottom face halves formed either an incongruent (e.g., angry top + happy bottom) or congruent composite expression (e.g., happy top + happy bottom). Participants reported the expression in the target top or bottom half of the face. In Experiment 1, the target half in the incongruent condition was identified less accurately and more slowly relative to the baseline isolated expression or neutral face conditions. In contrast, no differences were found between congruent and the baseline conditions. In Experiment 2, the effects of exposure duration were tested by presenting faces for 20, 60, 100 and 120 ms. Interference effects for the incongruent faces appeared at the earliest 20 ms interval and persisted for the 60, 100 and 120 ms intervals. In contrast, no differences were found between the congruent and baseline face conditions at any exposure interval. In Experiment 3, it was found that spatial alignment impaired the recognition of incongruent expressions, but had no effect on congruent expressions. These results are discussed in terms of holistic and analytic processing of facial expressions.

Using computerized games to teach face recognition skills to children with autism spectrum disorder: the Let's Face It! program.

BACKGROUND: An emerging body of evidence indicates that relative to typically developing children, children with autism are selectively impaired in their ability to recognize facial identity. A critical question is whether face recognition skills can be enhanced through a direct training intervention. METHODS: In a randomized clinical trial, children diagnosed with autism spectrum disorder were pre-screened with a battery of subtests (the Let's Face It! Skills battery) examining face and object processing abilities. Participants who were significantly impaired in their face processing abilities were assigned to either a treatment or a waitlist group. Children in the treatment group (N = 42) received 20 hours of face training with the Let's Face It! (LFI!) computer-based intervention. The LFI! program is comprised of seven interactive computer games that target the specific face impairments associated with autism, including the recognition of identity across image changes in expression, viewpoint and features, analytic and holistic face processing strategies and attention to information in the eye region. Time 1 and Time 2 performance for the treatment and waitlist groups was assessed with the Let's Face It! Skills battery. RESULTS: The main finding was that relative to the control group (N = 37), children in the face training group demonstrated reliable improvements in their analytic recognition of mouth features and holistic recognition of a face based on its eyes features. CONCLUSION: These results indicate that a relatively short-term intervention program can produce measurable improvements in the face recognition skills of children with autism. As a treatment for face processing deficits, the Let's Face It! program has advantages of being cost-free, adaptable to the specific learning needs of the individual child and suitable for home and school applications.

Why does selective attention to parts fail in face processing?

One hallmark of holistic face processing is an inability to selectively attend to 1 face part while ignoring information in another part. In 3 sequential matching experiments, the authors tested perceptual and decisional accounts of holistic processing by measuring congruency effects between cued and uncued composite face halves shown in spatially aligned or disjointed configurations. The authors found congruency effects when the top and bottom halves of the study face were spatially aligned, misaligned (Experiment 1), or adjacent to one another (Experiment 2). However, at test, congruency effects were reduced by misalignment and abolished for adjacent configurations. This suggests that manipulations at test are more influential than manipulations at study, consistent with a decisional account of holistic processing. When encoding demands for study and test faces were equated (Experiment 3), the authors observed effects of study configuration suggesting that, consistent with a perceptual explanation, encoding does influence the magnitude of holistic processing. Together, these results cannot be accounted for by current perceptual or decisional accounts of holistic processing and suggest the existence of an attention-dependent mechanism that can integrate spatially separated face parts.

A holistic account of the own-race effect in face recognition: evidence from a cross-cultural study.

A robust finding in the cross-cultural research is that people's memories for faces of their own race are superior to their memories for other-race faces. However, the mechanisms underlying the own-race effect have not been well defined. In this study, a holistic explanation was examined in which Caucasian and Asian participants were asked to recognize features of Caucasian and Asian faces presented in isolation and in the whole face. The main finding was that Caucasian participants recognized own-race faces more holistically than Asian faces whereas Asian participants demonstrated holistic recognition for both own-race and other-race faces. The differences in holistic recognition between Caucasian and Asian participants mirrored differences in their relative experience with own-race and other-race faces. These results suggest that the own-race effect may arise from the holistic recognition of faces from a highly familiar racial group.

Holistic and part-based face recognition in children with autism.

BACKGROUND: There is substantial evidence that children with autism are impaired in face recognition. Although many researchers have suggested that this impairment derives from a failure of holistic face processing and a tendency to represent and encode faces on a part-by-part basis, this hypothesis has not been tested directly. METHOD: Holistic face processing was assessed by comparing children's ability to recognize a face part (eyes, nose, or mouth) in the context of the whole face in which it was learned with their ability to recognize the same face part in isolation. RESULTS: In Study 1, as expected, typically developing 9-year-olds (n = 27) and 11-year-olds (n = 30) were significantly better at recognizing face parts presented in the whole than in the part test condition, and this effect was limited to upright faces and not found for inverted faces. Consistent with prior findings, typically developing children were most accurate when face recognition depended on the eyes. In Study 2, high-functioning children with autism (n = 22) evidenced a whole-test advantage for mouths only, and were markedly deficient when face recognition depended on the eyes. Their pattern of performance diverged from age- and IQ-matched comparison participants (n = 20), who performed similarly to the typically developing children in Study 1. CONCLUSIONS: These findings suggest that face recognition abnormalities in autism are not fully explained by an impairment of holistic face processing, and that there is an unusual significance accorded to the mouth region when children with autism process information from people's faces.