Eimer M
Universität München, Institut für Psychologie, Germany.
Psychophysiology. 1994 Mar;31(2):154-63. doi: 10.1111/j.1469-8986.1994.tb01035.x.
Visual event-related potentials were measured for peripheral target stimuli that were preceded by a peripheral square. Targets appeared either at the same location as the square or in the opposite visual hemifield. In Experiment 1, 75% of the trials were same-location trials, and in Experiment 2, same- and opposite-location trials were equiprobable. The subject's overt response was dependent either on the identity or on the location of the target. In both experiments, opposite-location targets elicited an enhanced P1 at posterior electrodes ipsilateral to the position of the letter. This enhancement may be due to a sensory inhibition of same-location targets. Same-location targets elicited an enhanced negativity between 130 and 300 ms, with a first peak located parietally and a second peak broadly distributed over midline electrodes. This effect was larger in Experiment 1 than in Experiment 2 and is interpreted as enhanced processing of same-location targets due to an attentional orienting process elicited by the peripheral square.
针对外周方形刺激之前出现的外周目标刺激，测量了视觉事件相关电位。目标刺激要么出现在与方形相同的位置，要么出现在对侧视觉半视野。在实验1中，75%的试验为同位置试验，而在实验2中，同位置和对侧位置试验的概率相等。受试者的明显反应取决于目标的特性或位置。在两个实验中，对侧位置的目标在字母位置同侧的后部电极上引发增强的P1波。这种增强可能是由于对同位置目标的感觉抑制。同位置目标在130至300毫秒之间引发增强的负波，第一个峰值位于顶叶，第二个峰值广泛分布在中线电极上。这种效应在实验1中比在实验2中更大，被解释为由于外周方形引发的注意定向过程，对同位置目标的加工增强。
