CEREBRAL CORTICAL MECHANISMS FOR EYE MOVEMENTS AND VISUAL ATTENTION

通过逆向刺激脑内上级丘神经元， 弓形额眼野，确定了细胞轴承眼 运动或注视信号，但不是那些周边视觉信号 信息从额叶皮层投射到上级丘。 这意味着大脑皮层只向大脑皮层发送运动信息。 脑干扫视眼动系统 接受扫视适应范式训练的猴子很快学会改变 他们对扫视内刺激的扫视幅度 步 在适应的情况下刺激上级丘产生 和不适应的情况下一样的扫视。 单个神经元的活动 也没有适应的证据：视觉和运动信号 从丘发出的是刺激的真实信号， 运动，而不是视觉帧中的运动信号， 被脑干刺穿 因此，扫视幅度的变化，这发生在一个 适应的结果在神经链中的早期位置得到补偿 从刺激到反应 一小部分有阅读障碍的人有注视现象， 不稳定性表现为扫视侵入或方波抽搐， 试图固定一个光点。 一剂哌醋甲酯 减少或消除扫视侵入， 提高了口头阅读和阅读的视觉力学 性能本身。

By antidromic stimulation in the superior colliculus of neurons in the arcuate frontal eye fields, it was determined that cells bearing eye movement or fixation signals but not those with peripheral visual information project to the superior colliculus from the frontal cortex. This implies that the cerebral cortex sends only a motor message to the brainstem saccadic eye movement system. Monkeys trained on a saccadic adaptation paradigm learn quickly to change the amplitude of their saccades in response to intrasaccadic stimulus steps. Stimulation of the superior colliculus in the adapted case yields the same saccades as the unadapted case. The activity of single neurons also shows no evidence of adaptation: the visual and movement signals emanating from the colliculus are the veridical signals for stimulus and movement, rather than movement signals in a visual frame which are modified by the brainstem. Thus the change in saccade amplitude which occurs as a result of adaptation is compensated for at early sites in the neural chain from stimulus to response. A small percentage of humans with reading disorders have fixational instability manifest by saccadic intrusions or square-wave jerks while they attempt to fixate a spot of light. A single dose of methylphenidate decreases or eliminates the saccadic intrusions and results in temporary improves in both the ocular mechanics of oral reading and the reading performance itself.