Kurtz D, Leiby C C, Butter C M
J Comp Physiol Psychol. 1982 Feb;96(1):35-46. doi: 10.1037/h0077864.
Rhesus monkeys discriminated between two color-differentiated stimuli presented on a screen only when they fixated the center of the screen. The stimuli were presented 8 degrees, 20 degrees, or 32 degrees from the screen's center, for 2 sec or 100 msec, a duration too brief to permit their fixation. Performance declined when the response sites, located either centrally (8 degrees eccentricity) or peripherally (32 degrees eccentricity), were separated from the stimuli, whether they were presented for 2 sec or 100 msec. These findings suggest that the stimulus-response separation effect is due to selective attention to the response sites and not to fixating them during stimulus presentation. Following superior colliculus lesions, the monkeys were impaired in discriminating between peripheral stimuli, but only when they responded centrally. This deficit was not due to (a) a failure to fixate the stimuli, for it occurred when the stimuli were 100 msec or 2 sec or (b) reduced sensory capacities, for it disappeared when the subjects responded peripherally. This deficit may reflect deficient attentional shifts from the response sites to the stimuli.
恒河猴只有在注视屏幕中心时，才能区分屏幕上呈现的两种颜色不同的刺激。刺激物呈现于距离屏幕中心8度、20度或32度的位置，持续时间为2秒或100毫秒，该持续时间过短，无法让它们进行注视。当位于中央（8度偏心度）或周边（32度偏心度）的反应部位与刺激物分开时，无论刺激呈现2秒还是100毫秒，表现都会下降。这些发现表明，刺激-反应分离效应是由于对反应部位的选择性注意，而不是在刺激呈现期间对它们进行注视。上丘损伤后，猴子在区分周边刺激方面受损，但仅当它们在中央做出反应时。这种缺陷不是由于（a）未能注视刺激物，因为当刺激物持续100毫秒或2秒时就会出现这种情况，也不是由于（b）感觉能力下降，因为当受试者在周边做出反应时这种情况就消失了。这种缺陷可能反映了从反应部位到刺激物的注意力转移不足。
