中文摘要：

局部注意干扰效应（Localized attentional interference, LAI）是指在视觉搜索任务中同时搜索在空间上分离的两个目标时,或者目标周围存在一个无关奇异项时,这两个关键刺激相距较近时产生的干扰现象。本实验采用视觉搜索范式,探讨了奖赏预期对局部注意干扰效应的影响。实验1采用双目标搜索任务,要求被试判断搜索画面中两个奇异项刺激的形状是否相同。结果显示奖赏条件和无奖赏条件都表现出显著的距离主效应,随着目标间距离增大,被试的正确率提高,反应时下降。同时,在远距离时,奖赏条件下的正确率高于无奖赏条件,而在近距离时,奖赏条件下的正确率反而低于无奖赏条件,即,奖赏条件下局部注意干扰效应反而增大。高动机状态增强了两个目标的表征,反而不利于解决局部注意干扰效应。实验2采用单目标搜索任务,要求被试判断特定目标的方位并忽略另一无关奇异项刺激。与实验1不同的是,实验2仅在无奖赏条件下观察到显著的距离主效应,即被试行为表现在远距离时更好；而在奖赏条件下,被试在近距离和远距离的表现一样好,即没有局部注意干扰效应。这说明在奖赏预期条件,个体可以有效抑制分心物刺激的干扰,将注意集中于目标刺激的加工,从而对局部注意干扰效应产生调节。整个研究表明,奖赏整体上能够提高对任务相关刺激的表征,并抑制任务无关刺激,虽然这并不总是能够提高任务表现。

英文摘要：

It is well documented that monetary reward improves performance of cognitive tasks by increasing task concentration and engagement. In the current study, we investigated the effect of reward expectation on the localized attentional interference effect （LAI）. LAI occurs when attending to a visual object degrades the processing of nearby objects, with the interference subsiding with increasing distance from the attended item. The reason for LAI is that, as the separation between the attended items decreases, stimuli presented within receptive fields of the same sets of neurons are processed in a mutually suppressive manner, competing for neural representation. We carried out three experiments combining cuing paradigm and visual search paradigm. A cue indicating the reward condition of each trial （incentive vs. non-incentive） was followed by the presentation of a search array containing two target items （in Experiment 1） or a target item and a salient distractor （in Experiments 2a and 2b）. In Experiment 1, participants were asked to discriminate whether the two shape singletons among a set of non-target items were of the same shape or not. The results showed that participants’ performance declined as the target separation reduced in both the incentive and the non-incentive conditions. The response accuracy in identifying the two targets was higher in the incentive condition than that in the non-incentive condition when the two targets were distant from each other, but the pattern was reversed when they were close to each other. Namely, the LAI effect was larger in the incentive condition than that in the non-incentive condition. In Experiments 2a and 2b, participants were asked to discriminate the orientation of a target while a salient distractor was presented in the search array. In contrast to Experiment 1, results from Experiment 2b revealed LAI effect in the non-incentive condition, but not in the incentive condition. In addition, shorter reaction times and higher response accuracy were observ