Handy T C, Mangun G R
Center for Cognitive Neuroscience, Dartmouth College, Hanover, NH 03755-3547, USA.
Percept Psychophys. 2000 Jan;62(1):175-86. doi: 10.3758/bf03212070.
Behavioral data have suggested that perceptual load can modulate spatial selection by influencing the allocation of attentional resources at perceptual-level processing stages (Lavie & Tsal, 1994). To directly test this hypothesis, event-related potentials (ERPs) were recorded for both low- and high-perceptual-load targets in a probabilistic spatial cuing paradigm. The results from three experiments showed that, as measured by the lateral occipital P1 and N1 ERP components, the magnitude of spatially selective processing in extrastriate visual cortex increased with perceptual load. Furthermore, these effects on spatial selection were found in the P1 at lower levels of perceptual load than in the N1. The ERP data thus provide direct electrophysiological support for proposals that link perceptual load to early spatial selection in visual processing. However, our findings suggest a relatively broader model--where perceptual load is but one of many factors mediating early selection.
行为数据表明，知觉负载能够通过在知觉水平加工阶段影响注意资源的分配来调节空间选择（拉维 & 察尔，1994）。为了直接验证这一假设，在概率性空间线索范式中，记录了低知觉负载和高知觉负载目标的事件相关电位（ERP）。三个实验的结果表明，以外侧枕叶P1和N1 ERP成分衡量，纹外视觉皮层中空间选择性加工的幅度随知觉负载增加。此外，在比N1更低的知觉负载水平下，P1中就发现了这些对空间选择的影响。因此，ERP数据为将知觉负载与视觉加工中的早期空间选择联系起来的观点提供了直接的电生理支持。然而，我们的研究结果表明了一个相对更宽泛的模型——其中知觉负载只是介导早期选择的众多因素之一。
