Exploring The Role Of Attention Control On Fronto-parietal Cortex Based On Transcranial Magnetic Stimulation

Humans receive a large amount of visual information every day in daily life,far exceeding the information load that the cerebral cortex can process.Therefore,in visual search,selective attention processing is required.Studies have shown that there are two control methods of selective attention,one is a goal-oriented top-down method;another is a stimulus-oriented bottom-up method.Cognitive neuroimaging revealed that important core brain regions for selective attention are in the frontal and parietal lobes.Therefore,this study used Transcranial Magnetic Stimulation(TMS)to intervene in the prefrontal lobe to explore the pathway impact of attentional control in brain imaging,and to explore the temporal characteristics of the interventional prefrontal and posterior parietal brain regions to explore specific regulation of the two attentional control.Study 1 used the continuous Theta Burst Stimulation(cTBS)technique in TMS to intervene the right dorsolateral prefrontal cortex(r DLPFC)of the brain,with the Vertex as the control site,and combined with Functional Magnetic Resonance Imaging(f MRI)was used to explore the changes in the attentional pathway brain regions and their effects on behavioral performance after intervention in the frontal cortex.The experiment uses a visual search paradigm including pop-out task and non-pop-out task,and uses two stimulation methods to intervene in r DLPFC and Vertex.It is found that after cTBS stimulates r DLPFC,cTBS on r DLPFC prolongs the reaction time under pop-out task when target appearing on the left.The f MRI results showed that in the whole-brain activation analysis,both the top-down and bottom-up attention mechanisms mainly involved the fronto-parietal,temporal,and limbic lobes.cTBS altered the neural activity of the prefrontal lobe,parietal lobe,hippocampus,and insula at rest,and the activity of these brain regions was also significantly correlated with visual search behavior.Study 2 used online TMS to stimulate the r DLPFC and the right Superior Parietal Lobule(r SPL)to explore the attentional mechanism of the fronto-parietal lobe in the early and later time windows of visual search.The results showed that when TMS stimulated r SPL,there was a significant difference in the accuracy of the subjects in the early and later time windows,but TMS on r DLPFC,there was no significant difference in the accuracy of the subjects in the early and later time windows.And both in the pop-out task and the non-pop-out task,compared with the early time,TMS prolonged the behavioral response time in the later time window on r DLPFC and r SPL.This study showed that cTBS inhibited bottom-up modulation of the left visual field,affecting neural activity in the prefrontal lobe,parietal lobe,hippocampus,and insula,and was significantly correlated with behavioral performance.In addition,TMS intervention on the frontal and parietal lobes in the early and later windows also has a certain regulatory effect on the two attentional control.