Neural correlates of interindividual differences in children's audiovisual speech perception

Area of Science:

• Neuroscience
• Developmental Psychology
• Speech Perception

Background:

• Children integrate auditory and visual cues for speech comprehension.
• The McGurk effect demonstrates multisensory integration, where auditory perception changes with visual input.
• Significant individual differences exist in children's susceptibility to the McGurk effect.

Purpose of the Study:

• To investigate if activity in the posterior superior temporal sulcus (STS) predicts susceptibility to the McGurk effect in children.
• To identify neural correlates of interindividual variability in audiovisual speech perception.

Main Methods:

• Used BOLD fMRI in 17 children (aged 6-12 years).
• Measured brain responses to McGurk incongruent, non-McGurk incongruent, and congruent audiovisual syllables.
• Employed independent functional localizers and whole-brain voxel-based regression analyses.

Main Results:

• Found significant differences in the left STS between McGurk perceivers and non-perceivers.
• Perceivers showed greater and prolonged STS hemodynamic responses to McGurk syllables compared to non-perceivers.
• Observed weaker differences in the fusiform face area and extrastriate visual cortex.

Conclusions:

• The posterior superior temporal sulcus (STS) plays a critical role in audiovisual speech perception.
• STS activity differences account for interindividual variability in children's McGurk effect perception.
• Findings highlight the neural basis of multisensory integration in speech comprehension.