University of California, Davis, VA, Medical Center, Martinez.
J Cogn Neurosci. 1997 Jan;9(1):75-91. doi: 10.1162/jocn.1997.9.1.75.
The contribution of prefrontal and posterior association cortex to voluntary and involuntary visual attention was as sessed using electrophysiological techniques in patients with focal lesions in prefrontal (n = 11), temporal-parietal (n = 10), or lateral parietal cortex (n = 7). Subjects participated in a task requiring detection of designated target stimuli embedded in trains of repetitive stimuli. Infrequent and irrelevant novel visual stimuli were randomly interspersed with the target and background stimuli. Controls generated attention dependent N1 (170 msec) and N2 (243 msec) potentials maximal over extrastriate cortex. Anterior and posterior association cortex lesions reduced the amplitude of both the N1 and N2 potentials recorded over extrastriate cortex of the lesioned hemisphere. The pattern of results obtained reveals that an intrahemispheric network involving prefrontal and posterior association cortex modulates early visual processing in extrastriate regions. Voluntary target detection generated a parietal maximal P300 response (P3b) and irrelevant novel stimuli generated a more frontocentrally distributed P300 (P3a). Cortical lesions had differential effects on P3a and P3b potentials. The P3b was not significantly reduced in any cortical lesioned group. Conversely, the P3a was reduced by both prefrontal and posterior lesions with decrements most severe throughout the lesioned hemisphere. These data provide evidence that an association cortex network involving prefrontal and posterior regions is activated during orientation to novel events. The lack of a significant effect on the visual target P3b in patients with novelty P3a reductions supports the notion that different neural systems are engaged during voluntary vs involuntary atten- tion to visual stimuli.
使用电生理学技术，评估了前额叶和后联合皮层对自愿和非自愿视觉注意的贡献，研究对象为前额叶（n=11）、颞顶叶（n=10）或外侧顶叶皮层（n=7）局灶性病变患者。受试者参与了一项需要检测嵌入重复刺激序列中的指定目标刺激的任务。罕见和不相关的新视觉刺激随机与目标和背景刺激混合。对照组产生了依赖于注意力的 N1（170ms）和 N2（243ms）电位，其最大值位于外侧纹状皮层。前联合和后联合皮层病变降低了病变半球外侧纹状皮层记录的 N1 和 N2 电位的振幅。获得的结果模式表明，涉及前额叶和后联合皮层的半球内网络调节了外侧纹状区域的早期视觉处理。自愿目标检测产生了顶叶最大 P300 反应（P3b），而不相关的新刺激产生了更额中央分布的 P300（P3a）。皮质病变对 P3a 和 P3b 电位有不同的影响。在任何皮质病变组中，P3b 都没有明显减少。相反，前额叶和后顶叶病变均降低了 P3a，病变半球的减少最为严重。这些数据提供了证据，表明涉及前额叶和后叶区域的联合皮层网络在定向新事件时被激活。在具有新颖 P3a 减少的患者中，对视觉目标 P3b 没有显著影响，这支持了不同的神经系统在自愿和非自愿注意视觉刺激时被激活的观点。
