Functional Mechanism of Multiple Cerebral Cortices on Task Switching:an ERP Study

This paper aims to investigate the task switching ERPs under the conditions of foreknowledge and non-foreknowledge,by using "task-switching" paradigm and taking the classification of Chinese characters or digits as tasks.Participants performed two tasks consecutively which were either task repetition(AA,BB,…) or task switching(AB,BA,…) in the experiment.The results indicated that the predecessor tasks of digit/word and succedent tasks of digit/word all evoked a negative-going wave which was larger for switching trials compared to repeating trials under foreknowledge conditions,and the difference waves in central regions were N-D320.However,under non-foreknowledge conditions,the succedent tasks of digit/word in switching trials evoked a negative-going wave compared to repeating trials only,and the difference waves in central regions were also N-D320.The results of Dipole Source Localization Analysis to difference waves disclosed that the endogenous preparation derived from left temporal region(Left BA20);the exogenous adjustment derived from right parietal region(Right BA19) under foreknowledge conditions while it derived from left frontal region(Left BA47) and right frontal region(Right BA10) under non-foreknowledge conditions.These results suggested that the nature of task switching was cognitive conflict and the corresponding ERP component was D-N320.Under foreknowledge conditions,task switching was solely in charge of temporal and parietal regions successively.It was the advance preparation that made task switching accomplishment in primary cortex,whereas under non-foreknowledge conditions task switching was accomplished in wilder senior cortex and activates left frontal region and right frontal region at the same time.The cortex for endogenous preparation and exogenous adjustment was dissociative under foreknowledge and non-foreknowledge conditions.