Blink and You Will Miss It: a Core Role for Fast and Dynamic Visual Processing in Social Impairments in Autism Spectrum Disorder

Testing the Hard to Test: A Pilot Study Examining the Role of Questionnaires in Eliciting Visual Behaviours in Children with Autistic Spectrum Disorder

PURPOSE

There is a higher prevalence of visual problems in children with Autistic Spectrum Disorder (ASD) compared with the neuro-typical population. Issues relating to visual perception can be evident as atypical visual behaviours (ViBes). The aim of the study was to compare findings of parents and eye health professionals using questionnaires to describe visual function in young children with ASD.

MATERIALS AND METHODS

Parents/Caregivers of patients diagnosed with ASD attending routine hospital eye clinics were invited to participate. A questionnaire to draw out presence of ViBes was completed by the parent prior to attending clinic. The clinician independently completed the same questionnaire and undertook a clinical ocular assessment.

RESULTS

32 children were recruited (mean age 7 years, range 4-11). Most caregivers indicated they had noted at least one atypical ViBe (97%, median 5, range 0-8). Parental-reported ViBe8 scores were higher than clinician-reported scores (p = 0.04). The most commonly reported ViBes by both groups related to use of vision at the same time as other senses, and atypical fixation (e.g. looking away during speech or side viewing). There was weak correlation between visual acuity and parental ViBe8 score (rho = 0.364) and no correlation between refractive error and parental ViBe8 score (rho = 0.047).

CONCLUSION

Clinicians were likely to under-report atypical visual function compared with parent. Refraction and visual acuity alone do not detect all visual problems in children with ASD. A Visual Behaviour (ViBe) questionnaire offers a structured approach and shared language to allow documentation of functional visual assessment for both parents, carers, and educational professionals. Use of the ViBe questionnaire may promote understanding between caregiver and professional and provide a baseline for visual behaviours.

The influence of dynamism and expression intensity on face emotion recognition in individuals with autistic traits

Face emotion recognition (FER) ability varies across the population, with autistic traits in the general population reported to contribute to this variation. Previous studies used photographs of posed facial expressions, while real social encounters involve dynamic expressions of varying intensity. We used static photographs and dynamic videos, showing peak and partial facial expressions to investigate the influence of dynamism and expression intensity on FER in non-clinical adults who varied in autistic traits. Those with high autistic traits had lower accuracy with both static peak and dynamic partial intensity expressions, when compared to low autistic trait participants. Furthermore, high autistic traits were linked to an accuracy advantage for dynamic compared with static stimuli in both partial and peak expression conditions, while those with low autistic traits demonstrated this dynamic advantage only for partial expressions. These findings reveal the differing importance of dynamism and expression intensity for FER across the non-clinical population and appear linked to self-reported social-communication skills. Furthermore, FER difficulties in autism might relate to the ability to integrate subtle, dynamic information, rather than static emotion categorisation alone.

A Role for Visual Memory in Vocabulary Development: A Systematic Review and Meta-Analysis

Although attention and early associative learning in preverbal children is predominantly driven by rapid eye-movements in response to moving visual stimuli and sounds/words (e.g., associating the word "bottle" with the object), the literature examining the role of visual attention and memory in ongoing vocabulary development across childhood is limited. Thus, this systematic review and meta-analysis examined the association between visual memory and vocabulary development, including moderators such as age and task selection, in neurotypical children aged 2-to-12 years, from the brain-based perspective of cognitive neuroscience. Visual memory tasks were classified according to the visual characteristics of the stimuli and the neural networks known to preferentially process such information, including consideration of the distinction between the ventral visual stream (processing more static visuo-perceptual details, such as form or colour) and the more dynamic dorsal visual stream (processing spatial temporal action-driven information). Final classifications included spatio-temporal span tasks, visuo-perceptual or spatial concurrent array tasks, and executive judgment tasks. Visuo-perceptual concurrent array tasks, reliant on ventral stream processing, were moderately associated with vocabulary, while tasks measuring spatio-temporal spans, associated with dorsal stream processing, and executive judgment tasks (central executive), showed only weak correlations with vocabulary. These findings have important implications for health professionals and researchers interested in language, as they advocate for the development of more targeted language learning interventions that include specific and relevant aspects of visual processing and memory, such as ventral stream visuo-perceptual details (i.e., shape or colour).

Faster social attention disengagement in individuals with higher autism traits

INTRODUCTION

Atypical visual and social attention has often been associated with clinically diagnosed autism spectrum disorder (ASD), and with the broader autism phenotype. Atypical social attention is of particular research interest given the importance of facial expressions for social communication, with faces tending to attract and hold attention in neurotypical individuals. In autism, this is not necessarily so, where there is debate about the temporal differences in the ability to disengage attention from a face.

METHOD

Thus, we have used eye-tracking to record saccadic latencies as a measure of time to disengage attention from a central task-irrelevant face before orienting to a newly presented peripheral nonsocial target during a gap-overlap task. Neurotypical participants with higher or lower autism-like traits (AT) completed the task that included central stimuli with varied expressions of facial emotion as well as an inverted face.

RESULTS

High AT participants demonstrated faster saccadic responses to detect the nonsocial target than low AT participants when disengaging attention from a face. Furthermore, faster saccadic responses were recorded when comparing disengagement from upright to inverted faces in low AT but not in high AT participants.

CONCLUSIONS

Together, these results extend findings of atypical social attention disengagement in autism and highlight how differences in attention to faces in the broader autism phenotype can lead to apparently superior task performance under certain conditions. Specifically, autism traits were linked to faster attention orienting to a nonsocial target due to the reduced attentional hold of the task irrelevant face stimuli. The absence of an inversion effect in high AT participants also reinforces the suggestion that they process upright or inverted faces similarly, unlike low AT participants for whom inverted faces are thought to be less socially engaging, thus allowing faster disengagement.

The “Primitive Brain Dysfunction” Theory of Autism: The Superior Colliculus Role

A better understanding of the pathogenesis of autism will help clarify our conception of the complexity of normal brain development. The crucial deficit may lie in the postnatal changes that vision produces in the brainstem nuclei during early life. The superior colliculus is the primary brainstem visual center. Although difficult to examine in humans with present techniques, it is known to support behaviors essential for every vertebrate to survive, such as the ability to pay attention to relevant stimuli and to produce automatic motor responses based on sensory input. From birth to death, it acts as a brain sentinel that influences basic aspects of our behavior. It is the main brainstem hub that lies between the environment and the rest of the higher neural system, making continuous, implicit decisions about where to direct our attention. The conserved cortex-like organization of the superior colliculus in all vertebrates allows the early appearance of primitive emotionally-related behaviors essential for survival. It contains first-line specialized neurons enabling the detection and tracking of faces and movements from birth. During development, it also sends the appropriate impulses to help shape brain areas necessary for social-communicative abilities. These abilities require the analysis of numerous variables, such as the simultaneous evaluation of incoming information sustained by separate brain networks (visual, auditory and sensory-motor, social, emotional, etc.), and predictive capabilities which compare present events to previous experiences and possible responses. These critical aspects of decision-making allow us to evaluate the impact that our response or behavior may provoke in others. The purpose of this review is to show that several enigmas about the complexity of autism might be explained by disruptions of collicular and brainstem functions. The results of two separate lines of investigation: 1. the cognitive, etiologic, and pathogenic aspects of autism on one hand, and two. the functional anatomy of the colliculus on the other, are considered in order to bridge the gap between basic brain science and clinical studies and to promote future research in this unexplored area.

Atypically slow processing of faces and non-faces in older autistic adults

Face recognition is a fundamental function that requires holistic processing. Differences in face processing have been consistently identified in autistic children, but it is unknown whether these differences persist across the adult lifespan. Using event-related functional magnetic resonance imaging, we measured holistic face processing with a rapid Mooney faces task in 50 autistic and 49 non-autistic participants (30–74 years). Behavioral tasks included a self-paced version of the same paradigm and a global–local processing task (Navon). Reduced detection rates for faces, but not non-faces, were found in autistic adults, including slower responses on all conditions. Without time constraints, differences in accuracy disappeared between groups, although reaction times in correctly identifying faces remained higher in autistic adults. The functional magnetic resonance imaging results showed lower activation in the left and right superior frontal gyrus in the autism group but no age-related differences. Overall, our findings point toward slower information processing speed rather than a face recognition deficit in autistic adults. This suggests that face-processing differences are not a core feature of autism across the adult lifespan.

The conceptual understanding of depth rather than the low-level processing of spatial frequencies drives the corridor illusion

Our objective was to determine how different spatial frequencies affect the perceptual size rescaling of stimuli in the corridor illusion. Two experiments were performed using the method of constant stimuli. In experiment 1, the task required participants to compare the size of comparison and standard rings displayed over the same background image. ANOVA on the points of subject equality (PSEs) revealed that the perceived size of the top and bottom standard rings changed as a function of the availability of the high, medium, and low spatial frequency information. In experiment 2, the task required participants to compare the size of a comparison ring presented outside of the background image with a standard ring presented inside it. ANOVA on the PSEs revealed that the apparent size of the top and not the bottom standard ring changed depending on the availability of medium spatial frequency information. Eye-tracking revealed that the spatial frequency range of the background image in the periphery affected participants' eye positioning, which may explain why the effects of different spatial frequencies fluctuated across experiments. Nonetheless, when we consider these findings together, we propose that the conceptual understanding of depth plays a more important role in explaining the corridor illusion than the low-level processing of depth information extracted from different spatial frequencies along separate channels.