Neural correlates of impaired motor-auditory prediction in Autism Spectrum Disorder

Individuals with autism spectrum disorder (ASD) have difficulties with the unexpected and unpredictable nature of external events. Prior knowledge of the statistics of the environment (i.e. priors, in terms of Bayesian statistical framework) can aid resolving these uncertainties. In individuals with ASD, these priors may either be ill-constructed or not appropriately combined with the actual sensory information, resulting in less-precise or attenuated priors (Pellicano and Burr, 2012). These ‘hypo-priors’ may cause a greater reliance on bottom-up incoming sensory signals, which in turn leads to every stimulus being experienced afresh. Here, we tested the hypo-priors hypothesis by examining the neural underpinnings of prediction of sensory consequences of motor actions in individuals with ASD and individuals with typical development (TD). In this experiment, subjects pressed a button at a steady pace, which generated a sound. In another condition, the sounds were replayed at the same pace. In individuals with TD, the auditory N1 potential induced by the sound was attenuated in the motor-auditory condition compared to the auditory-only condition, indicating that - as expected - the motor action predicted the sound and dampened the sensation (Bäss et al., 2008). In individuals with ASD, there was no auditory N1 attenuation, indicating that they relied more strongly on bottom-up auditory cues. These results show that individuals with ASD make less use of their priors to interpret the sensory environment and support the notion of hypo-priors as the underlying cause of atypical multisensory processing in ASD.