Walking delays auditory processing in humans alongside a global shift in aperiodic neural activity

Natural sensory processing unfolds during movement, yet human electrophysiology is usually measured under enforced stillness. Here, we used mobile EEG to test whether walking changes the timing of auditory processing. Thirty adults listened to lateralised pure tones while walking freely or standing. Walking led to a delay in auditory N1 latency (< 10 ms). Control analyses ruled out the possibility that the N1 delay was contaminated by foot strike related noise in EEG. Multivariate decoding further indicated a later emergence of sound location information during walking in the subset of participants with reliable decoding in both states. Walking also produced a scalp wide decrease in the aperiodic exponent of neural responses. A larger global exponent decrease was associated with a larger N1 delay across participants. Together, these findings show that natural walking reorganises the temporal dynamics of human auditory processing and link early sensory slowing to a global change in ongoing cortical state.