The Cognitive Neural Mechanisms Of Response Inhibition In The Count/No-Count Task

Response inhibition is an ability which can inhibit inappropriate behaviors,played an important role in the central execution.Being able to respond correctly and quickly to behaviors that needed to be suppressed is of great significance to the normal life of individuals.The Count/No-Count task is normally used to investigate the response inhibition,most studies on clinical mental disorders such as obsessive-compulsive disorder use the P3 amplitude induced by this task as an important indicator to judge the ability of response inhibition.Some studies found that No-Count stimuli induced a larger P3 amplitude than Count stimuli and believed that the P3 effect reflected the cognitive inhibition process.However,some other researchers found that No-Count stimuli evoked a smaller P3 amplitude relative to Count stimuli with no specific explains for it.Hence,the cognitive neural mechanism of P3 effect in the Count/No-Count task is unclear,that is,the cognitive neural mechanism of response inhibition is still unclear.Research on working memory suggests that P3 might be related to attention resource allocation.In the Count/No-Count task,Count stimuli evoked a working memory updating relative to No-Count stimuli,the P3 amplitude might be relative to the attention resources consumed by working memory update(counting process).This study aims to explore the role of working memory updating in the process of response inhibition in the Count/No-Count task,reveal the cognitive neural mechanism of response inhibition.In this study,we investigated the behavior and ERPs differences under different load conditions by changing the load of counting stimuli in the Count/No-Count task.If the working memory updating was included,then the different amounts of cognitive resources would be required for the different load conditions,a load effect would be founded in the response inhibition.In Experiment 1,behavioral indicators were used to investigate the differences in the consumption of cognitive resources by different response types(Count/No-Count)in the Count/No-Count task and the impact of cognitive load on response inhibition.30 undergraduates were selected.A dual task was adopted,that is,a probe task(left or right arrows)was added after the Count/No-Count stimuli.Participants were required to determine the direction of the arrow and press the button after completing the Count/No-Count task.Both high and low load conditions were set for counting stimuli.Under high load conditions,subjects were required to add 2 silently when the letter O was presented,and not respond when the letter X was presented.Under low load conditions,subjects were required to add 1 silently when the letter O was presented,and not respond when the letter X was presented.The probe stimuli was presented after the Count/No-Count stimuli,participants were required to determine the direction of the arrow,and press the “F” button when the arrow was the left,press the “J” button when the arrow was the right.By comparing the RT(reaction time)of the probe stimuli under different load conditions,the differences in the consumption of cognitive resources of different response types and the influence of cognitive load on the response inhibition were investigated.The results showed that the RTs of probe trials after No-Count stimuli were significant longer than the RTs of probe trials after Count stimuli,indicating the No-Count stimuli induced the inhibition process,more cognitive resources were required;the RTs in the high load condition(Count 2)were significant longer than the RTs in the low load condition(Count 1),revealed that the working memory updating was included when the Count stimuli was presented.Experiment 2 compared the difference of neural activity induced by Count/No-Count stimuli under different load conditions by manipulating the cognitive load during counting(P3 effect).28 undergraduates were selected.ERPs(event related potentials)technology was adopted to investigate the neural mechanism.By recording the ERPs induced by the Count/No-Count stimuli,we explored whether the Count stimulus produced a working memory updating process.The results showed that No-Count stimuli evoked a shorter N2 latency relative to Count stimuli,indicating an increased cognitive control ability for No-Count stimuli;Low load condition(Count 1)evoked a more positive parietal P3 component relative to high load condition(Count 2),indicating the parietal P3 component was consistent with the working memory updating,more cognitive resource was required with the increased of load.Taken together,the results of this study indicated that in the Count/No-Count task,response inhibition required more cognitive control than response activation.A working memory updating might be included in the Count task,the high-load task has higher cognitive requirements than the low-load task,requiring more cognitive resources.By adding a probe stimuli to the Count/No-Count task and manipulating the cognitive load,this study explored the differences in cognitive resources required for the two types of stimuli,and revealed whether the P3 effect reflected the process of working memory updating,providing evidence to support the revelation of the cognitive neural mechanism of response inhibition in the Count/No-Count task.This study starts from the neural mechanism of the brain,analyze the specific components of response inhibition in electrophysiology,explore the specific process of response inhibition and the main distribution location in the cerebral cortex.The research results have important scientific and clinical significance for the study of neurological and mental diseases.