Adults on the autism spectrum differ from neurotypical peers when self-generating but not passively-experiencing somatosensation: a high-density electrophysiological (EEG) mapping and virtual reality study.

Little is known about how different features of tactile inputs affect somatosensory perception in autism. In this study we combined high-density electroencephalography (EEG) and virtual reality (VR) to assess how the volition and pattern consistency of somatosensory stimulation influenced the electrophysiological responses in neurotypical (n = 30) and autistic (n = 30) adults. Specifically, we compared N1 and P300 amplitudes when vibrotactile stimulation were actively triggered by self-motion (Active) versus passively triggered by target-motion (Passive). We also measured the mismatch negativity (MMN) to assess how deviations in the pattern of stimulus duration affected the electrophysiological responses. We observed comparable responses regardless of pattern deviation in the MMN time window between groups, but different patterns of amplitude in this time frame based on whether the stimulation was Active or Passive. In the autism group we observed smaller N1 amplitudes in response to Passive, but not Active, vibrations as compared to the control group. Conversely, there were overall larger magnitude P300 amplitudes in the autism group, but comparable levels of Passive-to-Active attenuation between groups. Overall, the autism cohort demonstrated variation from the neurotypical cohort with respect to the volition of the stimuli, but there were comparable results between groups in response to pattern deviation. These findings suggest that there are subtle differences in how adults with and without autism handle self-generated and externally-generated somatosensory sensations.