University of California, Davis.
J Cogn Neurosci. 1994 Summer;6(3):267-75. doi: 10.1162/jocn.1994.6.3.267.
Abstract Hemispheric specialization and subcortical processes in visual anention were investigated in callosotomy (split-brain) patients by measuring reaction times to lateralized stimuli in a spatial cuing paradigm. Cuing effects were obtained for targets presented to the right hemisphere (left visual hemifield) but not for those presented to the left hemisphere. These cuing effects were manifest as faster reaction times when the cue correctly indicated the location of the subsequent target (valid trials), as compared to trials in which the cue and target appeared in opposite hemifields (invalid trials). This pattern suggests that the right hemisphere allocated attention to cued locations in either visual hemifield, whereas the left hemisphere allocated attention predominantly to the right hemifield. This finding is consistent with a body of evidence from studies in patients with cortical lesions who display different attentional deficits for right versus left hemisphere damage. Because the present pattern occurs in patients whose cerebral hemispheres are separated at the cortical level, it suggests that right hemisphere attentional allocation to events in the ipsilateral visual half-field is mediated in part via intact subcortical systems.
摘要 通过在空间提示范式中测量对侧化刺激的反应时间，研究了大脑半球分工和视觉注意力的皮质下过程在胼胝体切开术（裂脑）患者中的情况。对于呈现给右半球（左视觉半视野）的目标，可以获得提示效应，但对于呈现给左半球的目标则没有提示效应。与提示和目标出现在相反半视野（无效试验）的试验相比，当提示正确指示随后目标的位置时，这些提示效应表现为更快的反应时间（有效试验）。这种模式表明，右半球将注意力分配到两个视觉半视野中的提示位置，而左半球主要将注意力分配到右半视野。这一发现与来自皮质损伤患者的研究证据一致，这些患者显示出对右半球和左半球损伤的不同注意力缺陷。由于目前的模式发生在大脑半球在皮质水平分离的患者中，因此表明右半球对同侧视觉半视野中事件的注意力分配部分是通过完整的皮质下系统介导的。
