关键词: 视觉搜索, 选择性注意, Posner范式, 奖赏, 功能磁共振成像

Abstract: The ability to actively locate potential reward in our environment is highly adaptive. The interaction between reward and visual search was manifested at two levels in recent studies. On the one hand, exerting reward outcome could affect search reaction time and percent correct rate. On the other hand, the to-be-searched target itself with rewarding feature (e.g., food or money) could also affect behavioral performance. However, it is not clear how reward information dynamically switches on and modulates human fronto-parietal attentional network in visual search. In this project, by combining Posner spatial cueing paradigm and visual search paradigm, we manipulate the cue either predicting the target feature (rewarded vs. non-rewarded) or the target location (directional vs. non-directional), and the target feature (rewarded vs. non-rewarded) in visual search task. By using fast event-related functional magnetic resonance imaging (fMRI) technique, we aim at examining the following two questions: 1) at cue-period, the neural substrates of top-down attentional bias toward rewarding information, and how these substrates differed from the neural substrates subserving spatial attentional bias; 2) at target-period, the dynamic interaction between rewarding information and fronto-parietal attentional network, specifically, the neural correlates for orienting to correctly-informed target and for re-orienting from the incorrectly-informed target.

Key words: visual search, selective attention, Posner paradigm, reward, fMRI