Luck S J, Heinze H J, Mangun G R, Hillyard S A
Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093-0608.
Electroencephalogr Clin Neurophysiol. 1990 Jun;75(6):528-42. doi: 10.1016/0013-4694(90)90139-b.
Event-related potentials (ERPs) were recorded from 12 subjects as they attended to the left or right hemifield of a visual display while fixating a central point. Stimuli were presented to the left or right visual fields on separate trials (unilateral stimuli) or to both fields simultaneously (bilateral stimuli). In different conditions, the stimulus sequences contained only bilateral stimuli, only unilateral stimuli, or a mixture of unilateral and bilateral stimuli. Bilateral stimuli elicited an enhanced positivity lasting from about 75 to 250 msec that was largest at posterior electrode sites contralateral to the attended hemifield. The early phase of this attention-related positivity appeared to be an enhancement of the exogenous P1 component. In contrast, both the posterior P1 and N1 components were enhanced in response to attended unilateral stimuli. Moreover, the N1 attention effect was reduced when the preceding stimulus contained elements in the attended field. It was concluded that modulations of the N1 and P1 components in these experiments represent different aspects of visual spatial attention: N1 may represent the orienting of attention to a task-relevant stimulus, whereas P1 may represent a facilitation of early sensory processing for items presented to a location where attention is already focused.
在12名受试者注视中心点的同时，记录他们关注视觉显示器左半视野或右半视野时的事件相关电位（ERP）。刺激分别呈现给左视野或右视野（单侧刺激），或同时呈现给两个视野（双侧刺激）。在不同条件下，刺激序列仅包含双侧刺激、仅包含单侧刺激，或单侧和双侧刺激的混合。双侧刺激引发了一种增强的正电位，持续时间约为75至250毫秒，在与被关注半视野对侧的后电极部位最大。这种与注意力相关的正电位的早期阶段似乎是外源性P1成分的增强。相比之下，对被关注的单侧刺激的反应中，后P1和N1成分均增强。此外，当前一个刺激在被关注视野中包含元素时，N1注意力效应会降低。得出的结论是，这些实验中N1和P1成分的调制代表了视觉空间注意力的不同方面：N1可能代表将注意力定向到与任务相关的刺激上，而P1可能代表对呈现到注意力已经聚焦的位置的项目的早期感觉处理的促进。
