Face perception in autism spectrum disorder: Modulation of holistic processing by facial emotion

Autistic adults exhibit typical sensitivity to changes in interpersonal distance

The visual processing differences seen in autism often impede individuals' visual perception of the social world. In particular, many autistic people exhibit poor face recognition. Here, we sought to determine whether autistic adults also show impaired perception of dyadic social interactions-a class of stimulus thought to engage face-like visual processing. Our focus was the perception of interpersonal distance. Participants completed distance change detection tasks, in which they had to make perceptual decisions about the distance between two actors. On half of the trials, participants judged whether the actors moved closer together; on the other half, whether they moved further apart. In a nonsocial control task, participants made similar judgments about two grandfather clocks. We also assessed participants' face recognition ability using standardized measures. The autistic and nonautistic observers showed similar levels of perceptual sensitivity to changes in interpersonal distance when viewing social interactions. As expected, however, the autistic observers showed clear signs of impaired face recognition. Despite putative similarities between the visual processing of faces and dyadic social interactions, our results suggest that these two facets of social vision may dissociate.

No influence of emotional expression on size underestimation of upright faces

Faces are a primary means of conveying social information between humans. One important factor modulating the perception of human faces is emotional expression. Face inversion also affects perception, including judgments of emotional expression, possibly through the disruption of configural processing. One intriguing inversion effect is an illusion whereby faces appear to be physically smaller when upright than when inverted. This illusion appears to be highly selective for faces. In this study, we investigated whether the emotional expression of a face (neutral, happy, afraid, and angry) modulates the magnitude of this size illusion. Results showed that for all four expressions, there was a clear bias for inverted stimuli to be judged as larger than upright ones. This demonstrates that there is no influence of emotional expression on the size underestimation of upright faces, a surprising result given that recognition of different emotional expressions is known to be affected unevenly by inversion. Results are discussed considering recent neuroimaging research which used population receptive field (pRF) mapping to investigate the neural mechanisms underlying face perception features and which may provide an explanation for how an upright face appears smaller than an inverted one. Elucidation of this effect would lead to a greater understanding of how humans communicate.

Inferential Emotion Tracking reveals impaired context-based emotion processing in individuals with high Autism Quotient scores

Emotion perception is essential for successful social interactions and maintaining long-term relationships with friends and family. Individuals with autism spectrum disorder (ASD) experience social communication deficits and have reported difficulties in facial expression recognition. However, emotion recognition depends on more than just processing face expression; context is critically important to correctly infer the emotions of others. Whether context-based emotion processing is impacted in those with Autism remains unclear. Here, we used a recently developed context-based emotion perception task, called Inferential Emotion Tracking (IET), and investigated whether individuals who scored high on the Autism Spectrum Quotient (AQ) had deficits in context-based emotion perception. Using 34 videos (including Hollywood movies, home videos, and documentaries), we tested 102 participants as they continuously tracked the affect (valence and arousal) of a blurred-out, invisible character. We found that individual differences in Autism Quotient scores were more strongly correlated with IET task accuracy than they are with traditional face emotion perception tasks. This correlation remained significant even when controlling for potential covarying factors, general intelligence, and performance on traditional face perception tasks. These findings suggest that individuals with ASD may have impaired perception of contextual information, it reveals the importance of developing ecologically relevant emotion perception tasks in order to better assess and treat ASD, and it provides a new direction for further research on context-based emotion perception deficits in ASD.

Impaired grouping of ambient facial images in autism

Ambient facial images depict individuals from a variety of viewing angles, with a range of poses and expressions, under different lighting conditions. Exposure to ambient images is thought to help observers form robust representations of the individuals depicted. Previous results suggest that autistic people may derive less benefit from exposure to this exemplar variation than non-autistic people. To date, however, it remains unclear why. One possibility is that autistic individuals possess atypical perceptual learning mechanisms. Alternatively, however, the learning mechanisms may be intact, but receive low-quality perceptual input from face encoding processes. To examine this second possibility, we investigated whether autistic people are less able to group ambient images of unfamiliar individuals based on their identity. Participants were asked to identify which of four ambient images depicted an oddball identity. Each trial assessed the grouping of different facial identities, thereby preventing face learning across trials. As such, the task assessed participants’ ability to group ambient images of unfamiliar people. In two experiments we found that matched non-autistic controls correctly identified the oddball identities more often than our autistic participants. These results imply that poor face learning from variation by autistic individuals may well be attributable to low-quality perceptual input, not aberrant learning mechanisms.

The autistic brain can process local but not global emotion regularities in facial and musical sequences

Whether autism spectrum disorder (ASD) is associated with a global processing deficit remains controversial. Global integration requires extraction of regularity across various timescales, yet little is known about how individuals with ASD process regularity at local (short timescale) versus global (long timescale) levels. To this end, we used event-related potentials to investigate whether individuals with ASD would show different neural responses to local (within trial) versus global (across trials) emotion regularities extracted from sequential facial expressions; and if so, whether this visual abnormality would generalize to the music (auditory) domain. Twenty individuals with ASD and 21 age- and IQ-matched individuals with typical development participated in this study. At an early processing stage, ASD participants exhibited preserved neural responses to violations of local emotion regularity for both faces and music. At a later stage, however, there was an absence of neural responses in ASD to violations of global emotion regularity for both faces and music. These findings suggest that the autistic brain responses to emotion regularity are modulated by the timescale of sequential stimuli, and provide insight into the neural mechanisms underlying emotional processing in ASD.

Use of the Oxford face matching test reveals an effect of ageing on face perception but not face memory

Effects of ageing on both face perception and face memory have previously been reported. Previous studies, however, have not controlled for the effects of face perception when assessing face memory, meaning that apparent effects of ageing on face memory may actually be due to effects of ageing on face perception. Here, both face perception and face memory were assessed in a sample of adults ranging in age from 18 to 93, and the effect of age on face memory was assessed after controlling for face perception. Face perception was assessed using both a standard test and the Oxford face matching test (OFMT), deliberately designed to avoid the bias towards younger, neurotypical samples that may be present in other tests. An effect of ageing on face perception was found using both tests, with the unbiased OFMT being more sensitive to the effect of age. Importantly, when controlling for face perception using the OFMT, no effect of age on face memory was found. Indicative scores on the OFMT from a sample of 989 participants are provided, broken down by age and gender.

The Oxford Face Matching Test: A non-biased test of the full range of individual differences in face perception

Tests of face processing are typically designed to identify individuals performing outside of the typical range; either prosopagnosic individuals who exhibit poor face processing ability, or super recognisers, who have superior face processing abilities. Here we describe the development of the Oxford Face Matching Test (OFMT), designed to identify individual differences in face processing across the full range of performance, from prosopagnosia, through the range of typical performance, to super recognisers. Such a test requires items of varying difficulty, but establishing difficulty is problematic when particular populations (e.g., prosopagnosics, individuals with autism spectrum disorder) may use atypical strategies to process faces. If item difficulty is calibrated on neurotypical individuals, then the test may be poorly calibrated for atypical groups, and vice versa. To obtain items of varying difficulty, we used facial recognition algorithms to obtain face pair similarity ratings that are not biased towards specific populations. These face pairs were used as stimuli in the OFMT, and participants were required to judge whether the face images depicted the same individual or different individuals. Across five studies the OFMT was shown to be sensitive to individual differences in the typical population, and in groups of both prosopagnosic individuals and super recognisers. The test-retest reliability of the task was at least equivalent to the Cambridge Face Memory Test and the Glasgow Face Matching Test. Furthermore, results reveal, at least at the group level, that both face perception and face memory are poor in those with prosopagnosia, and are good in super recognisers.

Transdiagnostic Predictors of Impaired Recognition of Facial Emotion Expression in Adults with Autism Spectrum Disorder and Intellectual Disability

This study aims to evaluate the predictive capacity of executive dysfunction and social adaptation in performance in facial emotion recognition. The sample consisted of 31 adults with Intellectual Disabilities (ID) and Autism Spectrum Disorder (ASD). The variables that maintain significant correlations with emotional perception were taken as independent variables. Multiple regression analysis was used to identify the predictors of the facial stimuli perception in population with ASD. The results demonstrated a relationship between social maturity and emotional perception. Better scores in communication, socialization and daily life skills predict better performance in the perception of facial stimuli, both emotional and non-emotional.

ADOS-Eye-Tracking: The Archimedean Point of View and Its Absence in Autism Spectrum Conditions

Face perception and emotion categorization are widely investigated under laboratory conditions that are devoid of real social interaction. Using mobile eye-tracking glasses in a standardized diagnostic setting while applying the Autism Diagnostic Observation Schedule (ADOS-2), we had the opportunity to record gaze behavior of children and adolescents with and without Autism Spectrum Conditions (ASCs) during social interaction. The objective was to investigate differences in eye-gaze behavior between three groups of children and adolescents either (1) with ASC or (2) with unconfirmed diagnosis of ASC or (3) with neurotypical development (NTD) during social interaction with an adult interviewer in a diagnostic standard situation using the ADOS-2. In a case control study, we used mobile eye-tracking glasses in an ecologically valid and highly standardized diagnostic interview to investigate suspected cases of ASC. After completion of the ASC diagnostic gold standard including the ADOS-2, the participants were assigned to two groups based on their diagnosis (ASC vs. non-ASC) and compared with a matched group of neurotypically developed controls. The primary outcome measure is the percentage of total dwell times assessed for different areas of interest (AOI) with regard to the face and body of a diagnostic interviewer and the surrounding space. Overall, 65 children and adolescents within an age range of 8.3-17.9 years were included in the study. The data revealed significant group differences, especially in the central-face area. Previous investigations under laboratory conditions gave preferential attention to the eye region during face perception to describe differences between ASC and NTD. In this study - using an ecologically valid setting within a standard diagnostic procedure - the results indicate that neurotypically developed controls seem to process faces and facial expressions in a holistic manner originating from the central-face region. Conversely, participants on the Autism Spectrum (tAS) seem to avoid the central-face region and show unsystematic gaze behavior, not using the preferred landing position in the central-face region as the Archimedean point of face perception. This study uses a new approach, and it will be important to replicate these preliminary findings in future research.

Autism, autistic traits and creativity: a systematic review and meta-analysis

Psychometric, historiometric and psychiatric studies are controversial on a hypothetical link between psychopathology and creativity. In this study, we will try to contribute to this debate by analysing the case of autism. Is there a relationship between autism and creativity? If so, can we find the same relationship in a watered-down form in subjects with autistic traits? In order to answer these questions, we carried out a systematic literature review of the studies on this topic published in the last 10 years. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We also conducted a meta-analysis of data. We found that in the clinical population there are fewer creative performances than in control groups; nonetheless, it is possible to delineate a medium creative profile of subjects with autism. The average creative profile of people with autism shows that they are inhibited in fluency and flexibility, but that they display a high level of detail and a particularly high level of originality in works either generated during tests or created in private time. In particular, the level of detail reached in the latter condition seems to be higher in the autistic population than in the control groups. Better linguistic skills appear to be linked to better creative performances. Linguistic tests, if compared with visual and performative tests, seem to favour the expression of originality in subjects with autism. Although our data on autistic traits are compatible with the hypothesis that a high level of autistic traits is a watered-down replica of the cognitive profile of subjects with autism, we have no sufficient data to support this hypothesis.