Adaptation to the Speed of Biological Motion in Autism

Abstract

Autistic individuals often present atypicalities in adaptation-the continuous recalibration of perceptual systems driven by recent sensory experiences. Here, we examined such atypicalities in human biological motion. We used a dual-task paradigm, including a running-speed discrimination task ('comparing the speed of two running silhouettes') and a change-detection task ('detecting fixation-point shrinkages') assessing attention. We tested 19 school-age autistic and 19 age-and ability-matched typical participants, also recording eye-movements. The two groups presented comparable speed-discrimination abilities and, unexpectedly, comparable adaptation. Accuracy in the change-detection task and the scatter of eye-fixations around the fixation point were also similar across groups. Yet, the scatter of fixations reliably predicted the magnitude of adaptation, demonstrating the importance of controlling for attention in adaptation studies.

Prediction in Autism Spectrum Disorder: A Systematic Review of Empirical Evidence

“…The results further show reduced perceptual adaptation, which can be interpreted as reduced use of the expectation of stimulus repetition to improve stimulus discrimination. However, one study indicated that this effect may be attention‐dependent [Karaminis et al, 2020], as we discuss below.…”

“…Four more studies [Karaminis, Arrighi, Forth, Burr, & Pellicano, 2020; Turi et al, 2015; Turi, Karaminis, Pellicano, & Burr, 2016; van Boxtel, Dapretto, & Lu, 2016] looked at perceptual adaptation to recent stimuli. In Section 3.2.2 (Perceptual Adaptation), we describe how this effect can be understood as an effect of predicting that subsequent stimuli will be similar.…”

“…Four studies [Karaminis et al, 2020; Turi et al, 2015, 2016; van Boxtel et al, 2016] looked at the biasing influence of recent stimulus history on perception. In these studies, recent stimuli influence participants' perceptual reports by leading them to believe that the next stimulus was more different from its predecessor than it actually was.…”

“…Three of these studies showed reduced perceptual adaptation in the ASD group [Turi et al, 2015, 2016; van Boxtel et al, 2016]. The fourth found no evidence of reduced adaptation of judgements of biological motion [Karaminis et al, 2020], in apparent contradiction to the results of van Boxtel et al [2016]. The difference between these results may have been attributable to attentional differences, which, as shown by post hoc analysis of eye tracking data, had a significant impact on perceptual adaptation.…”

“…In both, neural responses were stronger in the ASD group for attended prediction errors but weaker for unattended prediction errors, suggesting that attention plays a powerful mediating role in predictive processes or prediction‐modulated responses in ASD. Karaminis et al [2020] provided evidence suggesting that perceptual adaptation in ASD participants may be normalized by attention. These results are not consistent with a uniform difficulty contextually modulating precision; rather, they suggest that top‐down attention may play an oversized role in precision modulation.…”