Internal noise measures in coarse and fine motion direction discrimination tasks, and the correlation with autism traits

Abstract

People with autism spectrum disorder (ASD) display abnormalities in motion processing. Motion perception abnormalities in ASD have been linked to high levels of internal noise (unreliable neuronal fluctuations), and deficits in motion pooling (integrating local motion into a global percept). However, the literature overall is equivocal. Traditionally, internal noise in ASD has been investigated through additive internal noise, comparing ASD and control groups. To date, multiplicative internal noise has not been investigated in ASD, and neither type of internal noise has been investigated in relation to traits of autism in the typically-developing population.Here, we investigate how additive and multiplicative internal noise and motion pooling vary across number of autistic traits in typically developed adults. We employed a visual motion integration task with a typically developed population, measuring autistic traits with the Autism Spectrum Questionnaire (AQ). Additive and multiplicative internal noise and motion pooling were calculated from task accuracy and consistency across a range of external noise levels, using a double-pass paradigm.We found that multiplicative noise (but not additive noise, or motion pooling) correlated with AQ. Specifically, multiplicative noise increased with AQ in a coarse motion discrimination task, while it decreased with AQ in a fine motion discrimination task. We suggest that the differences in multiplicative noise may be indicative of decision-variable fluctuations, which are smaller in individuals with a higher number of autistic traits, i.e., they are more focused. Our findings indicate that looking beyond additive noise and incorporating multiplicative noise estimation paradigms can help establish whether there are differences in internal noise levels between individuals with ASD and those without.

Does stochastic resonance improve performance for individuals with higher autism-spectrum quotient?

“…The degree to which an individual exhibits autistic traits can be measured using the Autism-spectrum Quotient (AQ), introduced by Baron-Cohen et al (2001), or the Social Responsiveness Scale (SRS-2) (Constantino and Gruber, 2012). Vilidaite et al (2017) showed, using a psychophysical double-pass paradigm, that the amount of internal noise was positively correlated with the degree to which participants exhibited autistic traits on the AQ [see also (Orchard et al, 2021)].…”