Effect of task set-modulating attentional capture depends on the distractor cost in visual search: evidence from N2pc
Effect of task set-modulating attentional capture depends on the distractor cost in visual search: evidence from N2pc
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DOI：
10.1097/wnr.0000000000000163
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发表时间：
2014-07
期刊：
影响因子：
1.7
通讯作者：
Dandan Zhao;Shengnan Liang;Zhenlan Jin;Ling Li
中科院分区：
文献类型：
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作者：
Dandan Zhao;Shengnan Liang;Zhenlan Jin;Ling Li
先前的研究已经证实，注意力可以被当前的任务集调节，同时不由自主地被突出项目所吸引。然而，当呈现不同任务集的相同刺激时，注意捕获的调节依赖于哪些因素，这一点尚不清楚。在本研究中，被试通过不同的目标和干扰物设置进行了两个具有相同搜索阵列的视觉搜索任务（颜色单一为目标，起始单一为干扰物，称为颜色任务，反之亦然）。同侧和对侧颜色干扰物分别在两个任务中产生两种不同的相对显著性。反应时间（RTs）和n2 -后对侧（N2pc）结果表明，同侧和对侧颜色干扰物在启动任务中没有差异。然而，与对侧起效的牵张器相比，RTs和N2pc的潜伏期对同侧起效的牵张器都有延迟。此外，在对侧干扰条件下，在颜色任务中观察到的N2pc被逆转，其振幅被减弱。在这些结果的基础上，我们提出了一个参数，称为分心物成本（DC），通过从同侧条件中减去对侧分心物条件下的RTs来计算。结果表明，DC增强可能与N2pc在寻找颜色目标时的修饰有关。综上所述，这些发现提供了视觉搜索中任务集调节注意力捕获的效果与DC相关的证据。
Previous studies have confirmed that attention can be modulated by the current task set while involuntarily captured by salient items. However, little is known on which factors the modulation of attentional capture is dependent on when the same stimuli with different task sets are presented. In the present study, participants conducted two visual search tasks with the same search arrays by varying target and distractor settings (color singleton as target, onset singleton as distractor, named as color task, and vice versa). Ipsilateral and contralateral color distractors resulted in two different relative saliences in two tasks, respectively. Both reaction times (RTs) and N2-posterior-contralateral (N2pc) results showed that there was no difference between ipsilateral and contralateral color distractors in the onset task. However, both RTs and the latency of N2pc showed a delay to the ipsilateral onset distractor compared with the contralateral onset distractor. Moreover, the N2pc observed under the contralateral distractor condition in the color task was reversed, and its amplitude was attenuated. On the basis of these results, we proposed a parameter called distractor cost (DC), computed by subtracting RTs under the contralateral distractor condition from the ipsilateral condition. The results suggest that an enhanced DC might be related to the modification of N2pc in searching for the color target. Taken together, these findings provide evidence that the effect of task set-modulating attentional capture in visual search is related to the DC.