Binocular rivalry dynamics associated with high levels of self-reported autistic traits suggest an imbalance of cortical excitation and inhibition

Abstract

An imbalance in cortical excitation and inhibition (E/I) may underlie both social and nonsocial symptoms of autism spectrum conditions (ASC). Recent work suggests that an E/I imbalance may underlie some of the sensory differences that are characteristic of ASCs such as anomalous perception. Binocular rivalry dynamics are thought to reflect the balance of E/I in the brain and could serve as a behavioural biomarker for ASC. Previous studies of clinical ASC populations have found a slower rate of binocular rivalry transitions; increased duration of the mixed percept and reduced perceptual suppression. There are some mixed reports of altered rivalry dynamics in the neurotypical population with high self-reported levels of autistic traits. Therefore, we used simple grating stimuli to measure binocular rivalry dynamics in a sample of seventy-nine adults aged 18 -55 years. We additionally measured the level of autistic traits with the AQ-10 and used CAPS as a measure of anomalous perception. Bayesian correlations showed that those with higher AQ scores had a slower rate of perceptual switching and a longer mixed percept duration. Significant regression models with CAPS and AQ score revealed that AQ score was a significant predictor of switch rate and mixed percept duration, whereas CAPS was not. We also report that CAPS significantly predicted perceptual suppression, whereas AQ score did not. Overall, our findings suggest that in a non-clinical population, autistic traits are a predictor of binocular rivalry dynamics and the cortical E/I imbalance thought to underlie symptoms of ASC may extend to the broader phenotype.

Visual consciousness dynamics in adults with and without autism

“…However, that study employed a large stimulus size, which is known to be biased toward mixed perception 20 . Later studies used smaller apertures and found longer durations of mixed perceptions (and fewer perceptual alternations) in adults with autism 31 – 33 and in neuro-typical adults with an elevated autistic symptomology 36 . Several studies have found that stereoacuity is reduced in autism compared to controls 37 , 38 and people with autism are more likely to have binocular vision disruptions due to strabismus and amblyopia 2 , 38 – 42 .…”

“…Several studies have investigated CBR in autism 30 – 36 , including mixed perception, but have not classified piecemeal or superimposition components. The first study concerning CBR and autism did not find a significant difference between autistic and control groups 30 .…”

Exploring the Relationship Between Binocular Imbalance and Myopia: Refraction with a Virtual Reality Platform

“…In recent years, BI has attracted more and more attention, especially in the field of dyslexia 11 and autism. 3 , 12 This is dependent on the imbalance of BR as one of the external manifestations of E/I balance condition, and which can be observed and studied by various tests. However, the studies focused on BI in vision problems were relatively limited, especially with myopia.…”

Excitation/Inhibition Modulators in Autism Spectrum Disorder: Current Clinical Research

“…As to the mechanisms of GABAergic inhibitory dysfunction, the link with core ASD symptoms in humans is still under investigation. The deficit in binocular rivalry, a visual function that is thought to rely on the balance of excitation/inhibition in the visual cortex, has been observed in ASD individuals ( Dunn and Jones, 2020 ). The link between GABA and binocular rivalry dynamics was found specifically absent in ASD pointing to an insufficient GABA inhibitory function ( Dunn and Jones, 2020 ).…”