Enhanced Integration of Motion Information in Children With Autism

Abstract

To judge the overall direction of a shoal of fish or a crowd of people, observers must integrate motion signals across space and time. The limits on our ability to pool motion have largely been established using the motion coherence paradigm, in which observers report the direction of coherently moving dots amid randomly moving noise dots. Poor performance by autistic individuals on this task has widely been interpreted as evidence of disrupted integrative processes. Critically, however, motion coherence thresholds are not necessarily limited only by pooling. They could also be limited by imprecision in estimating the direction of individual elements or by difficulties segregating signal from noise. Here, 33 children with autism 6 -13 years of age and 33 age-and ability-matched typical children performed a more robust task reporting mean dot direction both in the presence and the absence of directional variability alongside a standard motion coherence task. Children with autism were just as sensitive to directional differences as typical children when all elements moved in the same direction (no variability). However, remarkably, children with autism were more sensitive to the average direction in the presence of directional variability, providing the first evidence of enhanced motion integration in autism. Despite this improved averaging ability, children with autism performed comparably to typical children in the motion coherence task, suggesting that their motion coherence thresholds may be limited by reduced segregation of signal from noise. Although potentially advantageous under some conditions, increased integration may lead to feelings of "sensory overload" in children with autism.

Disentangling signal and noise in autism spectrum disorder

“…Despite the improved averaging ability, however, the children with ASD performed comparably to typical children in the standard motion coherence task. Manning et al (2015) drew two main conclusions from these data. Firstly, children with ASD outperformed typically developing children in the high-variability motion direction task, suggesting enhanced integration of local motion in ASD.…”

“…The authors used an adaptive staircase method in all three tasks to estimate thresholds. Manning et al (2015) found that children with ASD, compared to the typically developing children, were as sensitive to directional differences when all elements moved in the same direction (no-variability). Crucially, the children with ASD proved more sensitive to the average direction in the presence of directional variability (high-variability) than the typically developing children.…”

“…In an exciting recent study, Manning et al (2015) present data that speak directly to this issue by investigating the sensitivity to directional differences in motion display in children with and without ASD (matched on age and IQ). Children completed a direction integration task with two interleaved conditions (novariability and high-variability) in addition to a traditional motion coherence task.…”

“…It follows that we should be careful in stating that individuals with ASD cannot form informative priors (only ''weak" or low precision priors), as several authors seem to suggest (Manning, Tibber, Charman, Dakin, & Pellicano, 2015;Pellicano & Burr, 2012;Sinha et al, 2014;Zaidel, Goin-Kochel, & Angelaki, 2015). Surely, in lots of cases individuals with ASD can detect and learn to use regularities (in the form of informative priors).…”

Local Versus Global Processing in Autism: Special Section Editorial

“…One final note is that the contribution of one group to the IMFAR symposium in 2014 is published elsewhere (Manning et al 2015), and further contributes to the debate around local versus global processing of visual motion in ASD.…”