Recalibration of temporal order perception by exposure to audio-visual asynchrony.

The perception of simultaneity between auditory and visual information is of crucial importance for maintaining a coordinated representation of a multisensory event. Here we show that the perceptual system is able to adaptively recalibrate itself to audio-visual temporal asynchronies. Participants were exposed to a train of sounds and light flashes with a constant time lag ranging from -200 (sound first) to +200 ms (light first). Following this exposure, a temporal order judgement (TOJ) task was performed in which a sound and light were presented with a stimulus onset asynchrony (SOA) chosen from 11 values between -240 and +240 ms. Participants either judged whether the sound or the light was presented first, or whether the sound and light were presented simultaneously or successively. The point of subjective simultaneity (PSS) was, in both cases, shifted in the direction of the exposure lag, indicative of recalibration.