Repeatedly experiencing the McGurk effect induces long-lasting changes in auditory speech perception.

Area of Science:

• Cognitive Science
• Neuroscience
• Speech Perception

Background:

• The McGurk effect demonstrates audiovisual speech integration, where conflicting auditory and visual cues create a novel percept.
• Understanding the plasticity of speech perception is crucial for language acquisition and processing.

Purpose of the Study:

• To investigate whether repeated exposure to the McGurk effect can induce lasting changes in auditory-only speech perception.
• To characterize the nature and persistence of this induced perceptual change.

Main Methods:

• Participants experienced the McGurk effect daily for 14 days.
• Auditory-only speech perception was assessed before, during, and after the exposure period.
• A causal inference model was used to predict individual differences in recalibration.

Main Results:

• Repeated McGurk effect exposure led to fusion-induced recalibration (FIR), where auditory stimuli alone evoked the fused percept.
• FIR was talker- and syllable-specific and persisted for over a year in some participants.
• FIR was absent in participants who did not experience the McGurk effect, indicating it was driven by multisensory prediction error.

Conclusions:

• The study demonstrates that multisensory experiences can induce persistent, long-lasting changes in auditory speech perception.
• Fusion-induced recalibration highlights the dynamic nature of speech perception and its susceptibility to audiovisual integration.
• These findings have implications for understanding neural plasticity in language networks and potential applications in language learning interventions.