Luck S J, Hillyard S A
Department of Neurosciences, University of California, San Diego.
J Exp Psychol Hum Percept Perform. 1994 Oct;20(5):1000-14. doi: 10.1037//0096-1523.20.5.1000.
The identification of targets in visual search arrays may be improved by suppressing competing information from the surrounding distractor items. The present study provided evidence that this hypothetical filtering process has a neural correlate, the "N2pc" component of the event-related potential waveform. The N2pc was observed when a target item was surrounded by competing distractor items but was absent when the array could be rejected as a nontarget on the basis of simple feature information. In addition, the N2pc was eliminated when filtering was discouraged by removing the distractor items, making the distractors relevant, or making all items within an array identical. Combined with previous topographic analyses, these results suggest that attentional filtering occurs in occipital cortex under the control of feedback from higher cortical regions after a preliminary feature-based analysis of the stimulus array.
通过抑制周围干扰项的竞争信息，视觉搜索阵列中目标的识别可能会得到改善。本研究提供了证据，表明这种假设的过滤过程具有神经关联物，即事件相关电位波形的“N2pc”成分。当目标项被竞争性干扰项包围时会观察到N2pc，但当基于简单特征信息可将阵列判定为非目标时则不存在N2pc。此外，通过移除干扰项、使干扰项具有相关性或使阵列中的所有项都相同来抑制过滤时，N2pc会消失。结合先前的地形分析，这些结果表明，在对刺激阵列进行初步的基于特征的分析之后，注意力过滤在枕叶皮层中发生，并受来自更高皮层区域的反馈控制。
