The Research Of Brain Rule-adjustability Based On Electroencephalogram (EEG)

In daily production and life,human beings will face some unexpected situations or changes in the living environment,which requires individual cognitive behaviors to make corresponding adaptive adjustments to adapt to the new environment.This adaptive adjustment of cognitive behavior is cognitive flexibility.Cognitive flexibility runs through all aspects of human social life.Cognitive flexibility can be evaluated qualitatively and quantitatively through some psychological experimental paradigms.The classic experimental paradigm is mainly Task-switch,of which task cuing is an effective paradigm for assessing brain cognitive flexibility and is widely used in research of Brain Cognition and Brain Disease.The cue and subsequent target ratio in experiments is usually set as 1:1,1:2,1:4,and 1:8.In the experimental paradigm of 1:2,1:4 and 1:8,there are a more common phenomenon which is the reaction time of the 1th target is significantly longer than the reaction time of the subsequent target(2th target,3th target,...),and the accuracy of target1 task is significantly smaller than the subsequent target.Researchers generally believe that this phenomenon is caused by the update of cue.This study defines this phenomenon as the rule adaptability of the brain,and defines the difference between 1th target and subsequent target reaction time as the rule's adaptation cost.In order to deeply study the cognitive mechanism of the rule adjustability of brain,Task cuing of the dual task(rule 1: color;rule 2: shape)is designed,in which the ratio of cue and the subsequent target is 1:8.Electroencephalography(EEG)of 40 normal subjects were recorded,using event-related potential(ERP),power spectral density(PSD),and time-frequency analysis.Cognitive Mechanism of brain rule adjustability is deeply and meticulously researched in many ways,such as Event-related potential(ERP),Power spectral density(PSD),Time-frequency analysis,Phase Locking Value(PLV)and Brain Network.The finding of this thesis as follow:(1)For P200,the speed of the S-R mapping retrieval in 1th target was significantly slower than the 2-8th target,and the difference in reaction time is mainly caused by the difference in this retrieval speed.That is the more difference in this retrieval speed and the more difference in reaction time.Furthermore,1th target occupies more dorsal prefrontal cortex(DPFC)resources than 2-8th target,and the communication intensity between the dorsal and ventral frontoparietal network in 1th target was significantly greater than that of 2-8th target.(2)For N200,the conflict inhibition of the 1th target was significantly greater than the conflict inhibition of the 2-8th target.The speed of conflict inhibition in 1th target is significantly than the speed in 2-8th target,and the difference in reaction time is mainly caused by the difference of the speed of conflict inhibition.That is the more difference in this conflict inhibition and the more difference in reaction time.(3)For P300,the task difficulty in 1th target was greater than in 2-8th target.Furthermore,it is found that the speed of response selection in 1th target was significantly lower than in 2-8th target.(4)The frontoparietal network plays an important role in the cognitive process of this experiment,and 1th target occupies more frontoparietal network cognitive resources than 2-8th target.(5)In the cognitive process,the brain network information transmission efficiency in 1th target is higher than in 2-8th target.The above findings in this article provide a new way to understand the rule adjustability,and help us to understand the cognitive neural mechanisms related to the rule adjustability.