Feldmann-Wüstefeld Tobias, Schubö Anna
Philipps-University Marburg, Germany.
Philipps-University Marburg, Germany.
Brain Res. 2015 Dec 10;1629:196-209. doi: 10.1016/j.brainres.2015.10.018. Epub 2015 Oct 17.
Searching a target was shown to be facilitated when embedded in a homogeneous compared to a heterogeneous context. This study investigated extended attention deployment after visual search for a target that observers had to discriminate in contexts of varying heterogeneity. Results showed more efficient attention deployment towards targets in homogeneous contexts as evident in higher accuracy and larger N2pc amplitudes than in random contexts. RTs to subsequently presented probes were shorter and a larger posterior positivity was observed in the ERP when probes were presented at the target location compared to other locations. This on-target advantage was larger for homogeneous contexts at ISIs of 90ms, but not for shorter (30ms) or longer (150ms) ISIs. These results show that visual search tasks induce an accelerated attention deployment after homogeneous contexts, however with a delay after target discrimination compared to less demanding target detection.
与异质背景相比，当目标嵌入同质背景中时，搜索目标的过程会更顺利。本研究调查了在视觉搜索目标后注意力的扩展部署情况，观察者必须在不同异质性的背景中辨别该目标。结果表明，在同质背景中对目标的注意力部署更有效，这体现在与随机背景相比，具有更高的准确性和更大的N2pc波幅。与其他位置相比，当探测刺激出现在目标位置时，对随后呈现的探测刺激的反应时更短，并且在事件相关电位（ERP）中观察到更大的后部正波。在90毫秒的刺激间隔（ISI）下，这种目标位置优势在同质背景中更大，但在较短（30毫秒）或较长（150毫秒）的ISI下则不然。这些结果表明，视觉搜索任务在同质背景后会引发加速的注意力部署，然而与要求较低的目标检测相比，在目标辨别后会有延迟。
