| Response inhibition refers to the suppression of inappropriate behavior,which is very important for human survival and adaptation.Flexible adjustment of behavior is conducive to goal-oriented behavior.Some mental illnesses show deficits in response inhibition,while individual differences also exist in normal individuals.Working memory capacity(WMC)is one of the important indicators of individual cognitive function.Therefore,the study will take working memory capacity as an important indicator of individual differences to explore the brain mechanism of individual differences in response inhibition.Specifically,we will use the antisaccade task to measure the response inhibition ability of individuals and explore the mechanism of the effect of working memory capacity on the antisaccade.In this study,magnetic resonance imaging(MRI)with high spatial precision was used to investigate the differences in antisaccade behavior and brain mechanism between high and low capacity groups in healthy people from three directions: structure MRI,resting-state MRI and task-state MRI.In this study,the antisaccade paradigm was used to measure the response inhibition,and the classical word recognition memory task was used to measure the working memory capacity of individuals.In antisaccade task,the subjects were asked to inhibit reflexive saccade toward the suddenly appearing peripheral target and perform a volitional saccade toward the mirror position of the target.In this task,the accuracy and latency of the antisaccade were used as the main indexes to measure the ability of response inhibition.In the vocabulary recognition memory task,the subjects had to learn a series of words,and after a certain period of time,they had to judge whether the words presented were the words they had learned before.The detection rate of the learned words was used as the working memory capacity.The experimental results were as follows: 1)the latency of antisaccade was negatively correlated with the working memory capacity,indicating that the subjects with high capacity of working memory started antisaccade more quickly;2)in people with high working memory capacity,the performance of antisaccade increased with the decrease of gray matter volume in the middle frontal gyrus,and increased with the decrease of resting-state functional connection MRI(rs-fcMRI)in the middle frontal gyrus,while the performance of people with low working memory capacity was just the opposite;3)the greater the gray matter volume of in the left postcentral gyrus,the better the antisaccade performance of the subjects,and in population with high working memory capacity,the antisaccade performance of the subjects will be weakened with the increase of the strength of rs-fcMRI;4)in the study of event-related functional magnetic resonance imaging(fMRI),the effect of working memory capacity on the antisaccade was mainly manifested in the activation of the fronto-parietal network.The higher the activation degree of the left middle frontal gyrus and the inferior parietal lobule,the higher the performance of working memory capacity and the better the performance of the antisaccade.In this study,it was shown that young healthy people with different working memory capacity did differ in performance of response inhibition task,with high-capacity subjects performing better than low-capacity subjects.Further results of neural mechanism showed that the middle frontal gyrus of frontal lobe and the postcentral gyrus and the superior and inferior parietal lobule of the parietal lobe were the main brain areas affected by working memory capacity to antisaccade,and played different roles in people with high and low working memory capacity.These findings will provide a good reference for future research on the effects of working memory capacity on response inhibition,as well as an intermediate comparison for those studying brain mechanism differences between young patient and healthy control to exclude possible interference. |
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