Sensorimotor activity during speech perception is both pervasive and highly variable, changing as a function of the cognitive demands imposed by the task. The purpose of the current study was to evaluate whether the discrimination of Same (matched) and Different (unmatched) syllable pairs elicit different patterns of sensorimotor activity as stimuli are processed in working memory. Raw EEG data recorded from 42 participants were decomposed with independent component analysis to identify bilateral sensorimotor mu rhythms from 36 subjects. Time frequency decomposition of mu rhythms revealed concurrent event related desynchronization (ERD) in alpha and beta frequency bands across the peri- and post-stimulus time periods, which were interpreted as evidence of sensorimotor contributions to working memory encoding and maintenance. Left hemisphere alpha/beta ERD was stronger in Different trials than Same trials during the post-stimulus period, while right hemisphere alpha/beta ERD was stronger in Same trials than Different trials. A between-hemispheres contrast revealed no differences during Same trials, while post-stimulus alpha/beta ERD was stronger in the left hemisphere than the right during Different trials. Results were interpreted to suggest that predictive coding mechanisms lead to repetition suppression effects in Same trials. Mismatches arising from predictive coding mechanisms in Different trials shift subsequent working memory processing to the speech-dominant left hemisphere. Findings clarify how sensorimotor activity differentially supports working memory encoding and maintenance stages during speech discrimination tasks and have potential to inform sensorimotor models of speech perception and working memory.

言语感知期间的感觉运动既普遍又高度可变，随着任务施加的认知需求而变化。当前研究的目的是评估相同（匹配）和不同（不匹配）音节对的区分是否会在工作记忆中处理刺激时引发不同的感觉运动模式。从 42 名参与者记录的原始 EEG 数据通过独立成分分析进行分解，以识别 36 名受试者的双侧感觉运动 mu 节律。mu 节律的时间频率分解揭示了刺激前后时间段内 alpha 和 beta 频带中的并发事件相关去同步 (ERD)，这被解释为感觉运动对工作记忆编码和维持的贡献的证据。在刺激后期间，不同试验中左半球 α/β ERD 比相同试验更强，而右半球 α/β ERD 在相同试验中比不同试验更强。半球之间的对比显示在相同试验中没有差异，而在不同试验期间，左半球的刺激后 α/β ERD 比右半球更强。结果被解释为表明预测编码机制导致相同试验中的重复抑制效应。不同试验中由预测编码机制引起的不匹配将随后的工作记忆处理转移到以语音为主的左半球。