Neural mechanism of salient target processing in college students / 中华行为医学与脑科学杂志

ABSTRACT

ObjectiveTo investigate the neural mechanism of processing the salient target during the visual search task with spatiotemporal patterns of event-related potential(ERP).MethodsSixteen subjects were asked to judge the existence of a low or high salient target from 4 items,in which one distractor might be also salient or not.A two-way repeated-measure ANOVA was carried out for behavioral performance and ERP data( distractor saliencyYES,NO)*( targetnone,low salient,high salient).ResultsSignificant interaction was found between target and distractor for the reaction time (F( 1.99,29.79) =21.56,P=0.00).For the low salient target,significant difference of reaction time was found between the YES (552.57 ± 82.32 ms) and NO (540.47 ± 75.68 ms)of distractor saliency( t (15) =- 2.489,P =0.025 ).However,such difference of reaction time was not significant for the high salient target.The statistical parametric mapping of F-value of ERP suggested the effect of the distractor saliency revealed in the right fronto-parietal-temporal areas related to stimulus novelty and the effect of the target saliency appeared in the parietal-occipital regions related to visual processing during the same stage ( 350 ～ 450ms ).The significant interaction occurred in the left temporal regions (450 ～ 600 ms ) related to stimulus familiarity and its classification.ConclusionDue to both mechanisms of the parallel processing for the target and the distractor during the perceptual stage and the effective classification of the familiar network within left hemisphere during the stage of pattern classification,the salient target can be processed quickly in spite of the interference from the salient distractor.