Brown V J, Robbins T W
Department of Experimental Psychology, University of Cambridge, United Kingdom.
J Neurosci. 1989 Mar;9(3):983-9. doi: 10.1523/JNEUROSCI.09-03-00983.1989.
Hungry rats were trained to report the occurrence and location of brief, unpredictable visual stimuli presented to the left of their heads in 1 of 2 response locations. After training, they received unilateral infusions of 6-hydroxydopamine, depleting dopamine throughout the head of the caudate putamen, either on the left or the right side, that is, either ipsilateral or contralateral to the side on which they were required to respond. Following an ipsilateral lesion there were no impairments in localization of the visual discriminanda and there was no lengthening of reaction time. The contralaterally lesioned rats, however, showed considerably lengthened reaction times to both stimuli and a profound bias to the nearer of the 2 response locations. Evidence from probe trials in which the visual stimuli were presented separately or simultaneously showed that the impairment was not due to a failure to localize the stimuli in contralateral space but, rather, resulted from a deficit in directing responses in contralateral space. It is suggested that this may be due to a distortion in the representation of response space.
饥饿的大鼠经过训练，以报告在其头部左侧呈现的短暂、不可预测的视觉刺激的出现和位置，刺激出现在两个反应位置中的一个。训练后，它们接受单侧注射6-羟基多巴胺，使尾状壳核头部的多巴胺耗尽，注射部位在左侧或右侧，即与它们需要做出反应的一侧同侧或对侧。同侧损伤后，视觉辨别物的定位没有受损，反应时间也没有延长。然而，对侧损伤的大鼠对两种刺激的反应时间都显著延长，并且对两个反应位置中较近的位置有明显的偏向。在视觉刺激分别或同时呈现的探测试验中得到的证据表明，损伤不是由于无法在对侧空间中定位刺激，而是由于在对侧空间中引导反应的缺陷。有人认为，这可能是由于反应空间表征的扭曲。
