Ito M, Westheimer G, Gilbert C D
The Rockefeller University, New York, New York 10021, USA.
Neuron. 1998 Jun;20(6):1191-7. doi: 10.1016/s0896-6273(00)80499-7.
Brightness discrimination thresholds and facilitation by lateral interaction were measured in five human observers and two monkeys. The subjects judged the brightness of one of four peripherally seen lines against a reference. This experiment was performed both when the observer was cued to the position of the test line (focused attention) and when there was no cue (distributed attention). Discrimination was better with focused than with distributed attention. When the test line had a collinear flank, its brightness was enhanced; this enhancement was four times more prominent with distributed than with focused attention. After training, thresholds improved and collinear facilitation decreased under distributed but not under focused attention. The findings show that there are fewer benefits from contextual interaction once attention is directed toward a visual location, and that the attentional effects are subject to training.
在五名人类观察者和两只猴子身上测量了明度辨别阈值以及侧向相互作用产生的促进作用。受试者根据一个参考标准判断四条外周可见线条中某一条的明度。该实验在观察者被提示测试线条位置（集中注意力）时以及未给予提示（分散注意力）时均进行。集中注意力时的辨别比分散注意力时更好。当测试线条有共线侧翼时，其明度会增强；这种增强在分散注意力时比集中注意力时显著四倍。经过训练后，在分散注意力而非集中注意力的情况下，阈值提高且共线促进作用减弱。研究结果表明，一旦注意力指向一个视觉位置，情境相互作用带来的益处就会减少，并且注意力效应会受到训练的影响。
