Sub-second timing irregularities in a simple motor task in autism spectrum disorder: preliminary effects of intermittent light stimulation.

BACKGROUND: Several authors have now contributed to the neurocognitive understanding of timing. In Autism Spectrum Disorder (ASD) on the other hand little is known about timing representations and its functioning. In this study we have adapted a simple finger-tapping motor task, with a timing component, as we aim at understanding whether the processing of time is preserved in this population. METHODS: We have tested a group of people on the spectrum of autism without intellectual disabilities and a control sample recruited from the general population, matched for age, gender, schooling and general cognitive abilities on this task with a learning and testing phase. In the testing phase we have added two exploratory conditions where participants were exposed to intermittent light stimulation of 4Hz and 8Hz. RESULTS: Results show that both in the learning and testing phase, besides troubles in the motor component encountered by the people on the spectrum, their timing component performance was also problematic. This reveals to be specially true for time intervals below the 1 second range, whereas performance in longer intervals is clearly preserved. It was also observed that, the exposure to intermittent light stimulation specifically overcomes the difficulties observed in the autistic group, at the timing components at this millisecond time range.CONCLUSION: The observed timing difficulties in this group seem to be restricted to the system responsible for the processing of time intervals in the milliseconds range, which helps accommodating disparate findings in the literature.