Department of Experimental and Biological Psychology, Philipps-University Marburg, Marburg, Germany.
Psychophysiology. 2013 Aug;50(8):722-33. doi: 10.1111/psyp.12061. Epub 2013 Jun 4.
In visual search, similar nearby stimuli can be grouped and thus enhance processing of an embedded target. The aim of the present study was to examine the time course of attention deployment after a brief presentation of stimulus arrays of different heterogeneity. Targets in less heterogeneous, grouped contexts yielded higher accuracy and larger N2pc amplitudes than targets in more heterogeneous, random contexts, indicating more efficient selection in the former. Subsequently presented probes yielded shorter reaction times and a larger posterior positivity when presented at the target location. This advantage was more pronounced after grouped compared to random contexts at the shorter compared to the longer interstimulus interval. The results show that less heterogeneous contexts that allow for grouping not only enhance processing of stimuli within that context, but have a sustained effect on visual attention.
在视觉搜索中，类似的邻近刺激可以被分组，从而增强对嵌入目标的处理。本研究的目的是考察在呈现不同同质性的刺激数组后，注意力部署的时间进程。在同质性较低、分组的情况下，目标的准确性更高，N2pc 波幅更大，而在同质性较高、随机的情况下，目标的准确性和 N2pc 波幅则较低，这表明前者的选择更有效。随后呈现的探测刺激在目标位置时，反应时间更短，后正成分更大。与较长的刺激间间隔相比，在较短的刺激间间隔下，分组的情况下比随机的情况下，这种优势更为明显。研究结果表明，允许分组的同质性较低的上下文不仅增强了对该上下文内刺激的处理，而且对视觉注意力具有持续的影响。
