Reduced perceptual exclusivity during object and grating rivalry in autism

Abstract

The dynamics of binocular rivalry may be a behavioral footprint of excitatory and inhibitory neural transmission in visual cortex. Given the presence of atypical visual features in Autism Spectrum Conditions (ASC), and the growing evidence in support of the idea of an imbalance in excitatory/inhibitory neural transmission in animal and genetic models of ASC, we hypothesized that binocular rivalry might prove a simple behavioral marker of such a transmission imbalance in the autistic brain. In support of this hypothesis, we previously reported a slower rate of rivalry in ASC, driven by longer transitional states between dominant percepts. We tested whether atypical dynamics of binocular rivalry in ASC are specific to certain stimulus features. 53 participants (26 with ASC, matched for age, sex, and IQ) participated in a binocular rivalry experiment in which the dynamics of rivalry were measured at two levels of stimulus complexity, low (grayscale gratings) and high (colored objects). Individuals with ASC experienced a slower rate of binocular rivalry, driven by longer transitional states between dominant percepts. These exaggerated transitional states were present at both low and high levels of stimulus complexity (gratings and objects), suggesting that atypical binocular dynamics in autism are robust with respect to stimulus choice. Interactions between stimulus properties and rivalry dynamics in autism indicate that achromatic grating stimuli produce stronger group differences. These results confirm the finding of atypical dynamics of binocular rivalry in ASC. These dynamics were present for stimuli of both low and high levels of visual complexity, suggesting a pervasive imbalance in competitive interactions throughout the visual system of individuals with ASC.

Hypersensitivity to low intensity fearful faces in autism when fixation is constrained to the eyes

“…We speculate that our results could reflect an imbalance between excitatory and inhibitory (E/I) influences in the socio‐affective processing system in ASD, mirroring E/I imbalance for lower level stimulus processing [Freyberg et al, ; Robertson et al, ; Rosenberg et al, ]. In a brain with an overactive subcortical system [Hadjikhani et al, ; Zürcher et al, ], and hypersensitive to emotions, a way to decrease emotional reactivity would be to use the frontal parts of the brain to inhibit the emotional response, or to disengage from the face, as previously hypothesized in ASD [Tanaka and Sung, ].…”

Binocular rivalry in children on the autism spectrum

“…Furthermore, both of these parameters of binocular rivalry were also highly predictive of clinical measures of autistic symptomatology [ADOS‐G; Lord, Rutter, DiLavore, & Risi, ]. Notably, however, more than half of the autistic participants failed to reach the cut‐off for an autism spectrum disorder on the diagnostic assessment, the ADOS‐G [but see Freyberg, Robertson, & Baron‐Cohen, , Robertson, Ratai, & Kanwisher, ].…”

“…Robertson et al's [] results have recently been replicated [Freyberg et al, ; Robertson et al, ]. Freyberg et al [] measured binocular rivalry between two types of stimuli, gratings [low complexity, as in Said et al, ] and objects [high complexity/nonsocial, as in Robertson et al, ], and tested a slightly larger sample of adult participants, which was also more rigorously assessed for autistic symptomatology. This study also showed that the altered rivalry dynamics found in the autistic group did not depend on stimulus complexity: mixed‐percept durations were longer for gratings than for objects in both groups.…”

Evidence that eye‐movement profiles do not explain slow binocular rivalry rate in bipolar disorder: support for a perceptual endophenotype

“…The blocks were separated by 110‐second rest breaks and the trials by 30‐second rest breaks. The first few minutes of BR viewing have been characterized by increases in BR rate within individuals . However, BR rates stabilize with longer BR viewing periods, yielding a more accurate recording of an individual's BR rate.…”