McGurk illusion recalibrates subsequent auditory perception.
Visual information can alter auditory perception. This is clearly illustrated by the well-known McGurk illusion, where an auditory/aba/ and a visual /aga/ are merged to the percept of 'ada'. It is less clear however whether such a change in perception may recalibrate subsequent perception. Here we asked whether the altered auditory perception due to the McGurk illusion affects subsequent auditory perception, i.e. whether this process of fusion may cause a recalibration of the auditory boundaries between phonemes. Participants categorized auditory and audiovisual speech stimuli as /aba/, /ada/ or /aga/ while activity patterns in their auditory cortices were recorded using fMRI. Interestingly, following a McGurk illusion, an auditory /aba/ was more often misperceived as 'ada'. Furthermore, we observed a neural counterpart of this recalibration in the early auditory cortex. When the auditory input /aba/ was perceived as 'ada', activity patterns bore stronger resemblance to activity patterns elicited by /ada/ sounds than when they were correctly perceived as /aba/. Our results suggest that upon experiencing the McGurk illusion, the brain shifts the neural representation of an /aba/ sound towards /ada/, culminating in a recalibration in perception of subsequent auditory input.
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, the Netherlands.
Claudia S
CS
Lüttke
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, the Netherlands.
Matthias
M
Ekman
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, the Netherlands.
Marcel A J
MA
van Gerven
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, the Netherlands.
Floris P
FP
de Lange
D000328:Adult; D001303:Auditory Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007088:Illusions; D008279:Magnetic Resonance Imaging; D008297:Male; D055815:Young Adult