The Role Of The Left Primary Motor Cortex In Processing Chinese Action Verbs

Background: The motor cortex is responsible for controlling the sound of the vocal organs and plays an important role in the process of language production.However,whether it is involved in semantic processing has been a controversial issue in the field of language cognition.Repetitive transcranial magnetic stimulation(rTMS)provides a new perspective to explore this problem.In this study,This study aims to explore the effect of the left primary motor cortex on semantic processing of vocabulary by using rTMS technology,in order to understand the role and mechanism of motor cortex in semantic processing.Methods: 24 participants(healthy,regularly active undergraduate)were recruited(data from 3 participants were discarded: two participants in the intervention group voluntarily quit the experiment,and 1 participant due to extremely low accuracy rate in word recognition task.Finally,21 participants’ data were included in statistical analysis).The left primary motor cortex(M1)was selected as the target brain region,c-TBS paradigm in rTMS technique was used to intervene the participants.The control intervention was sham stimulation.Before and after rTMS intervention,the measurements of the word recognition task and Flanker task were performed.Results:(1)In the semantic categorization task,the RT of difference of action verbs was significantly greater than that of nouns in the experimental group;there was no significant difference in the RT of difference between action verbs and nouns in the control group.(2)In the Flanker task,ACC of consistent stimulus was significantly higher than that of inconsistent stimulus,and RT of consistent stimulus condition was significantly lower than that of inconsistent stimulus;Conclusion: The findings support the theory that M1 is directly involved in the representation of action verbs.