Time may be compressed in sound representation as replicated in sensory memory

The flow of time in the real world may differ from the one in the neural representation of auditory scene stored in the sensory memory, because the encoded information is free from the rule of actual time. The sensory memory underlying the automatic discriminative system is reflected by the mismatch negativity (MMN). The time-wise image of preceding sounds is integrated into the sensory memory as a 160-170 ms epoch. We measured the mismatch field (MMNm) and the reaction time responding to the omitted segments incorporated into a complex sound. The main result was that the encoded period from early to late omitted segment was shorter than the actual one, suggesting that time may be compressed in the sound representation.