Sensorimotor contributions to working memory differ between the discrimination of Same and Different syllable pairs

Area of Science:

• Neuroscience
• Cognitive Science
• Speech Perception Research

Background:

• Sensorimotor activity during speech perception is variable and influenced by cognitive task demands.
• Understanding sensorimotor contributions to working memory during speech processing is crucial.

Purpose of the Study:

• To investigate if discriminating same (matched) and different (unmatched) syllable pairs evokes distinct sensorimotor activity patterns.
• To examine how sensorimotor activity supports working memory encoding and maintenance during speech discrimination.

Main Methods:

• Utilized electroencephalography (EEG) data from 42 participants.
• Applied independent component analysis to isolate bilateral sensorimotor mu rhythms in 36 subjects.
• Performed time-frequency decomposition of mu rhythms to analyze event-related desynchronization (ERD) in alpha and beta bands.

Main Results:

• Observed concurrent event-related desynchronization (ERD) in alpha and beta bands, indicating sensorimotor involvement in working memory.
• Found stronger left hemisphere alpha/beta ERD in Different trials compared to Same trials post-stimulus.
• Identified stronger right hemisphere alpha/beta ERD in Same trials than Different trials post-stimulus.

Conclusions:

• Repetition suppression in Same trials may result from predictive coding mechanisms.
• Mismatches in Different trials shift working memory processing to the left hemisphere.
• Sensorimotor activity differentially supports working memory stages in speech discrimination, informing models of speech perception.