Neurophysiological correlates of short-term recognition of sounds: Insights from magnetoencephalography

This study employed a same versus different auditory paradigm to investigate short-term auditory recognition within a predictive coding (PC) framework. Using magnetoencephalography (MEG), we captured the neurophysiological correlates associated with a single-sound, short-term memory task. Twenty-six healthy participants were tasked with recognizing presented sounds as same or different compared to strings of standards. Awhite noise interlude separated targets from standards. MEG sensor-level results revealed that recognition of same sounds elicited two significantly stronger negative components of the event-related field compared to different sounds. The first, N1m, peaking 100 ms post-sound onset, while the second corresponded to a slower negative component arising between 300 and 600 ms. This effect was observed in several significant clusters of MEG sensors, especially temporal and parietal regions. Conversely, different sounds produced scattered and smaller clusters of stronger activity than same sounds, peaking later than 600 ms after sound onset. Source reconstruction using beamforming algorithms revealed involvement of auditory cortices, hippocampus, and cingulate gyrus in both conditions. Overall, results are coherent with PC principles and previous results on the brain mechanisms underlying auditory recognition, highlighting the relevance of early and later negative brain responses for successful prediction of previously listened sounds in the context of conscious short-term memory.