Sensory integration in parietal but not auditory cortex mediates multisensory integration and recalibration
* Presenting author
During the ventriloquist effect (VE) a sound is mislocalized towards a visual cue. This VE induces a change in the perceived location of a subsequent unisensory sound - the ventriloquist after-effect, a form of multisensory recalibration (VAE). We investigated the neural mechanisms of these phenomena. We measured magnetoencephalography (MEG) while participants performed an auditory localization task. Psychometric data confirmed both VE and VAE. We used cross-validated classification to localize MEG source activity encoding current and previous sensory information, and regression modelling to determine when and where neural activity reflecting auditory encoding is influenced by the previous sensory information, and where this is predictive of the VE and VAE response biases.We found neural signatures of audio-visual integration (the VE bias) in superior temporal and parietal cortex. Of these, activity in parietal regions mediated the behavioural recalibration of unisensory auditory perception (the VAE bias). This suggests that parietal, but not auditory cortex, integrates audio-visual information and combines this with persistent representations about prior stimuli to guide adaptive multisensory behaviour.