Dean P, Redgrave P, Molton L
J Neurophysiol. 1984 Oct;52(4):625-37. doi: 10.1152/jn.1984.52.4.625.
It is unclear whether rats with lesions of the superior colliculus (SC) neglect visual stimuli because a) they fail to notice the stimuli or b) they notice the stimuli but fail to make specific orienting movements of the eyes and head toward them. To investigate this issue, we used an index of "noticing" that does not involve overt orienting movements, namely, desynchronization of the cortical electroencephalogram (EEG) in drowsy animals. In the first experiment, large collicular lesions with some invasion of surrounding areas severely impaired EEG desynchronization to a brief overhead flash of light but did not significantly affect desynchronization to brief bursts of white noise. No impairment was found after control lesions of cerebral cortex overlying the superior colliculus or of striate cortex. A subsequent experiment found that the visual impairment was still present when lesions were confined to the superior colliculus. It appears that rats with lesions of the superior colliculus can, in certain circumstances, fail to notice visual stimuli and that in rats, the superior colliculus is concerned not only with specific orienting movements to visual stimuli but also with visual desynchronization of the cortical EEG.
上丘（SC）受损的大鼠是否忽视视觉刺激尚不清楚，原因如下：a）它们未注意到刺激；b）它们注意到了刺激，但未能做出眼睛和头部朝向刺激的特定定向动作。为了研究这个问题，我们使用了一种“注意”指标，该指标不涉及明显的定向动作，即在昏昏欲睡的动物中皮层脑电图（EEG）的去同步化。在第一个实验中，大面积的丘脑部损伤并伴有周围区域的一些侵犯，严重损害了EEG对头顶短暂闪光的去同步化，但对EEG对短暂白噪声爆发的去同步化没有显著影响。在上丘上方的大脑皮层或纹状皮层进行对照损伤后未发现损伤。随后的实验发现，当损伤局限于上丘时，视觉损伤仍然存在。看来，上丘受损的大鼠在某些情况下可能无法注意到视觉刺激，并且在大鼠中，上丘不仅与对视觉刺激的特定定向动作有关，还与皮层EEG的视觉去同步化有关。
