Hearing the world differently: examining predictive coding accounts of autism using MEG

Predictive coding accounts of autism suggest that autistic perception is characterised by divergent precision weighting. The precise nature of this divergence, however, is debated. Here, we sought to disentangle competing predictive coding accounts of autism by testing them at a neural level. To this end, we used paediatric magnetoencephalography to record the auditory evoked fields of 10 young autistic children (M = 6.2 years, range = 4.2– 8.6) and 63 neurotypical children (M = 6.1 years, range = 3.0– 9.8) as they listened to a roving auditory oddball paradigm. For each participant, we subtracted the evoked responses to the ‘standard’ from the ‘deviant’ pure tones to calculate the mismatch field ‘MMF’: an electrophysiological component that is widely interpreted as a neural signature of predictive coding. We found no significant differences between the two groups’ MMF amplitudes, p > .05. An exploratory analysis indicated larger MMF amplitudes in most of the autistic children compared to their average-age-matched neurotypical counterparts, p < .05. We interpret these findings as preliminary evidence in support of the ‘inflexibly high prior and sensory precision’ account, and against the ‘inflexibly low prior-relative-to-sensory precision’ accounts of autistic perception.