Inhibitory Control Mechanisms In Voluntary Language Switching: Evidence From Behavior And Electrophysiolog

Basing on the Inhibitory Control Model(Green,1998),previous studies have systematically explored the internal processing mechanism of language switching and found that inhibitory control is an important processing mechanism of bilingual language switching.However,findings of previous studies were mainly based on the mandatory language switching,which had low ecological validity.The processing mechanism of the voluntary language switching,which occurs more frequently in daily life,remains controversial.Based on the controversy between the inhibitory control model and the lexical accessibility-only account,the present study aimed to investigate if the inhibitory control processing existed in the voluntary language switching and how the inhibition control processing was implemented in the voluntary language switching,by comparing the internal cognitive processing mechanism underlying the voluntary and mandatory language switching through the event related potential(ERP)technique.This dissertation aimed to investigate whether the inhibitory control processing mechanism exists in the voluntary language switching and the discrepancy of voluntary and mandatory language switching from ERPs level.In the first study,we examined whether there is a mechanism of inhibitory control in voluntary language switching from the behavioral level.In this experiment,inexperienced Chinese-English bilinguals were recruited to complete a behavioral experiment of voluntary language switching.The results showed that there were classical effects of language switching cost and reversed language dominance effect in the voluntary language switching,indicating that the inexperienced bilinguals had inhibition control processing in the voluntary language switching task.In the second study,we investigated whether there were differences in the inhibitory control processing mechanism between voluntary and mandatory language switching.In this experiment,inexperienced Chinese-English bilinguals were recruited to complete the behavioral experiment of voluntary and mandatory language switching.At the same time,the physiological electrical signals of the participants were measured by ERP technology.Experiment 2’s behavioral results showed that the inhibitory control exists in both mandatory language switching and voluntary language switching.And the inhibitory control consisting in the mandatory language switching is larger than voluntary language switching.Taken the mandatory language switching as a reference,from the ERP result,we can find that for reactive inhibitory control,the switch cost of N2 and LPC indicator in the mandatory language switching was significantly different from that in the voluntary language switching.In contrast,for proactive inhibitory control,significant difference on reversed language dominance effect between both tasks was only observed on LPC indicator.In conclusion,this study found that inhibitory control is an important processing mechanism of voluntary language switching,and its inhibitory control processing is significantly different from that of mandatory language switching.