Wijers A A, Lange J J, Mulder G, Mulder L J
University of Groningen, The Netherlands.
Psychophysiology. 1997 Sep;34(5):553-65. doi: 10.1111/j.1469-8986.1997.tb01742.x.
The event-related potential (ERP) effects of visual spatial attention and letter target detection for stimuli presented against a (nonisoluminant) dark background or against an isoluminant grey background were investigated. The goal was to study how the perceptual variable of luminance would influence early ERP reflections of selective attention. Such effects could further substantiate the claim that selective attention operates at the level of early perceptual processing and could provide evidence regarding the role of different visual routes in selective attention. Isoluminance increased the peak latency of the early ERP deflections (NP80, P1, and N1) by 40-50 ms. The ERP effects of spatial attention, consisting of P1 and N1 amplitude enhancements, were similarly delayed by isoluminance, supporting the idea that early selective processing is strongly dependent on bottom-up perceptual processing. P300 latency and reaction time were delayed by 70-75 ms, the additional delay probably reflecting that isoluminance affected decision processes in addition to perceptual processes. Isoluminance left the scalp topographies of the early ERP deflections largely unaffected, although a slight shift of the N1 topography in the isoluminant condition toward more inferior lateral posterior regions of the scalp could have reflected an increased contribution from ventral (occipitotemporal) brain areas. Relative to nontarget letters, targets presented at both attended and unattended spatial positions elicited an early contralaterally dominant lateral occipitotemporal negativity (N2pc). This ERP component is proposed to reflect an early, partly automatic process of template matching, consistent with indications from spatiotemporal dipole modelling that the N2pc was generated in inferior occipitotemporal brain regions.
研究了在（非等亮度的）暗背景或等亮度灰色背景下呈现刺激时，视觉空间注意和字母目标检测的事件相关电位（ERP）效应。目的是研究亮度这一感知变量如何影响选择性注意的早期ERP反映。此类效应可进一步证实选择性注意在早期感知处理水平上起作用的观点，并可为不同视觉通路在选择性注意中的作用提供证据。等亮度使早期ERP偏转（NP80、P1和N1）的峰值潜伏期增加了40 - 50毫秒。由P1和N1振幅增强组成的空间注意的ERP效应同样因等亮度而延迟，这支持了早期选择性处理强烈依赖自下而上的感知处理这一观点。P300潜伏期和反应时间延迟了70 - 75毫秒，额外的延迟可能反映出等亮度除了影响感知过程外，还影响了决策过程。等亮度在很大程度上未改变早期ERP偏转的头皮地形图，尽管在等亮度条件下N1地形图向头皮更下外侧后部区域略有偏移，这可能反映了腹侧（枕颞）脑区的贡献增加。相对于非目标字母，在注意和未注意的空间位置呈现的目标均引发了早期对侧优势的枕颞外侧负波（N2pc）。该ERP成分被认为反映了早期部分自动的模板匹配过程，这与时空偶极子模型的结果一致，即N2pc是在枕颞下部脑区产生的。
