Yamaguchi S, Tsuchiya H, Kobayashi S
Third Division of Internal Medicine, Shimane Medical University, Izumo, Japan.
Brain. 1994 Jun;117 ( Pt 3):553-62. doi: 10.1093/brain/117.3.553.
The neural processes underlying shifts of visuospatial attention were studied in normal adults by non-invasive recording of brain electrical activity. Event-related evoked potentials (ERPs) were recorded during target detection tasks with targets preceded by central or peripheral directional cues in the visual field, which are hypothesized to provoke voluntary and reflexive shifts of spatial attention. Reaction time to targets varied as a function of cue type and cue-target interval, indicating that the tasks induced shifts of spatial attention across the visual field. Event-related evoked potential recordings showed that central cues elicited negative potential shifts starting 240 ms after cue onset over posterior scalp sites contralateral to the cued visual field, which spread to anterior scalp sites over time. After 500 ms post cue, negative potentials were more negative in right temporal parietal sites regardless of cue direction. Peripheral cues enhanced the N1 component (140-200 ms post cue) over the contralateral hemisphere. Following N1 enhancement, a sustained negative potential shift appeared after 460 ms post cue at posterior scalp sites contralateral to cued field and spread over the temporal and central regions. These results suggest that the neural processes underlying spatial selection are initiated in the posterior region and that other cortical activities are recruited in a serial fashion. Symmetrical early activation of each contralateral hemisphere suggest independent involvement of the hemispheres in the early stages of shifting attention toward the contralateral visual field. A predominant contribution of the right hemisphere to sustained spatial attention was demonstrated in the late stage of cue processing at the right temporal and parietal regions. Different ERP patterns generated by central and peripheral cues support the hypothesis that distinct neural systems are involved in voluntary and reflexive mechanisms of attention shift.
通过对大脑电活动进行无创记录，研究了正常成年人视觉空间注意力转移背后的神经过程。在目标检测任务中记录事件相关诱发电位（ERP），目标之前有视野中的中央或外周方向线索，据推测这些线索会引发空间注意力的自愿和反射性转移。对目标的反应时间随线索类型和线索 - 目标间隔而变化，表明这些任务诱导了整个视野的空间注意力转移。事件相关诱发电位记录显示，中央线索在提示开始后240毫秒，在提示视野对侧的后头皮部位引发负电位转移，并随着时间扩散到前头皮部位。在提示后500毫秒，无论提示方向如何，右侧颞顶叶部位的负电位更负。外周线索增强了对侧半球的N1成分（提示后140 - 200毫秒）。在N1增强之后，在提示后460毫秒，在提示视野对侧的后头皮部位出现持续的负电位转移，并扩散到颞叶和中央区域。这些结果表明，空间选择背后的神经过程始于后部区域，并且其他皮质活动以连续方式被募集。每个对侧半球的对称早期激活表明，半球在向对侧视野转移注意力的早期阶段独立参与。在右侧颞叶和顶叶区域的提示处理后期，证明了右半球对持续空间注意力的主要贡献。中央和外周线索产生的不同ERP模式支持了这样的假设，即不同的神经系统参与了注意力转移的自愿和反射机制。
