Brain Mechanism for Exogenous Facilitation and Inhibition of Return in Visual Search
基于视觉搜索的外源易化和返回抑制脑机制研究

Exogenous orienting plays an important role in orienting to visual space. In this study, the authors investigated the different effects of exogenous attention in parallel and serial visual search tasks by recording event-related brain potentials (ERPs) from subjects detecting probes following a search task. When exogenous attention remained at the serial search locations, a delayed response was observed (i.e., IOR) and three ERP components appeared: a Pd200 at he posterior parietal areas, an Nd240 at the left prefrontal areas, and an Nd280 at the bilateral temporoparietal areas. When exogenous attention remained at parallel search locations, a faster response was observed (exogenous facilitation). At this time, one ERP component appeared: an Nd280 at the middle occipito-parietal areas. It is found that the exogenous facilitation-related neural process occurs at approximately 280 ms, and the neural processes which occur around 200 and 240 ms were inhibitory-specific events in the serial search task. These results suggest that the exogenous facilitation and IOR involve different brain areas and/or neural processes that may appear independently and are therefore most likely two dissociable processes.