Walsh V, Ellison A, Ashbridge E, Cowey A
Department of Experimental Psychology, University of Oxford, UK.
Neuropsychologia. 1999 Feb;37(2):245-51. doi: 10.1016/s0028-3932(98)00099-2.
Our previous studies of the role of the parietal cortex in visual learning and attention showed that the right parietal cortex is required for normal performance on conjunction visual search tasks but that its role depends on whether subjects are naive or trained on the task. Here we extend these findings in two Experiments. Experiment 1 shows that magnetic stimulation of the left parietal cortex also impairs performance (measured as reaction time) on conjunction visual search tasks, but only when the target is present in the right (contralateral) visual field. Stimulation of the same region on a feature detection task speeds up performance significantly when the target is in the left (ipsilateral) visual field. Experiment 2 explores further the role of the right parietal cortex in learning conjunction search tasks. Stimulation of the right parietal cortex in subjects who had already trained on some visual search tasks did not impair performance on a novel motion/form conjunction task even though the search was clearly serial. Stimulation of area V5, however, severely disrupted performance on the same task. These data indicate that the role of the parietal cortex may change much earlier in the course of training than initially thought.
我们之前关于顶叶皮层在视觉学习和注意力方面作用的研究表明，右侧顶叶皮层对于联合视觉搜索任务的正常表现是必需的，但其作用取决于受试者是新手还是经过该任务训练。在此，我们通过两个实验扩展了这些发现。实验1表明，对左侧顶叶皮层进行磁刺激也会损害联合视觉搜索任务的表现（以反应时间衡量），但仅当目标出现在右侧（对侧）视野时。当目标在左侧（同侧）视野时，对同一区域进行刺激会显著加快特征检测任务的表现。实验2进一步探究了右侧顶叶皮层在学习联合搜索任务中的作用。在已经接受过一些视觉搜索任务训练的受试者中，对右侧顶叶皮层进行刺激并不会损害新的运动/形状联合任务的表现，即便该搜索明显是序列性的。然而，对V5区域进行刺激会严重干扰同一任务的表现。这些数据表明，顶叶皮层的作用在训练过程中可能比最初认为的更早发生变化。
