Brain Mechanism Of Distractor Location Cue Triggered Distractor Suppression

In daily life,people are easily influenced by distractions that lead to inefficient allocation of attention,thus reducing productivity.Distractor Suppression is the brain's ability to filter task-irrelevant information,which helps to allocate attentional resources rationally and complete tasks quickly and accurately.As an important component of selective attention,distractor suppression has been a hot topic of research in recent years.To investigate the brain mechanisms of distractor suppression,the present study designed a visual search experimental paradigm in which distractor suppression is triggered by cues to the location of distractors.In the experiment,half of the blocks had cues to cue the location of the distractor,and the other half had no cues.In each block,the distractor was presented in only half of the trials.The experiment explored the brain basis mechanisms related to distractor suppression based on behavioral and magnetic resonance brain imaging data from 30 subjects.The behavioral results showed that the location cues of the distractor accelerated the processing of the target when the distractor was presented,indicating that the location cues triggered distractor suppression,but did not accelerate the processing of the target when no distractor was presented.The results of the task state functional imaging data showed that activity in brain regions such as the bilateral frontoparietal lobe during the cueing phase was stronger in the spatial cueing condition than in the no-cueing condition,and that the cueing effect in the left prefrontal lobe was positively correlated with the cueing effect in behavioral performance,suggesting an important role of the prefrontal lobe in distractor suppression.During the visual search phase,the presentation of distractors enhanced activity in brain regions that were more posterior compared to the cue phase,such as the bilateral temporo-occipital lobe,the right insula,and the right parietal lobe,and the cueing effect in these brain regions was associated with a weakening as the cueing effect for behavioral performance increased.Further analysis revealed a stronger activation in the left middle occipital gyrus for distractions rather than targets in the right visual field,indicating a stronger processing state in the visual cortex for the location of the distractor.In contrast,the location cue of the distractor inhibited right insula activity in the absence of the distractor,suggesting that it may be involved in reducing the processing of the distractor.Based on these results,a dynamic causal analysis of the four brain regions(frontal middle gyrus,superior parietal lobule,occipital middle gyrus,and insula)revealed that distractor location cues enhanced the mutual inhibitory connections from the frontal lobe to the occipital lobe,the inhibitory connections from the parietal lobe to the insula,and the excitatory connections from the frontal and occipital lobes to the insula,indicating that the insula plays an important role in the directed connections to the frontoparietal and occipital lobes.Finally,voxel-based morphometric analysis revealed that gray matter volume in the right postcentral gyrus decreased with enhanced distractor suppression and gray matter volume in the left lingual gyrus increased with enhanced distractor suppression,reflecting the relationship between gray matter volume of brain structures and distractor suppression.In summary,this paper mainly identified brain regions such as frontoparietal,occipital and insula involved in distractor suppression and revealed the importance of the functional activity relationship between them.In addition,this paper identified the contribution of anatomical features of brain regions such as postcentral gyrus and lingual gyrus to individual differences in distractor suppression.