McCarthy G, Luby M, Gore J, Goldman-Rakic P
Neuropsychology Laboratory, Veterans Affairs Medical Center, West Haven 06516, USA.
J Neurophysiol. 1997 Mar;77(3):1630-4. doi: 10.1152/jn.1997.77.3.1630.
P300 is an event-related potential elicited by infrequent target events whose amplitude is dependent on the context provided by the immediately preceding sequence of stimuli, suggesting its dependence on working memory. We employed magnetic resonance imaging sequences sensitive to blood oxygenation level to identify regional changes evoked by infrequent visual target stimuli presented in a task typically used to elicit P300. Targets evoked transient event-related activation bilaterally in the middle frontal gyrus, in the inferior parietal lobe, and near the inferior aspect of the posterior cingulate gyrus beginning within 1.5 s of target onset and peaking between 4.5 and 6 s. These regions have been identified in previous neuroimaging studies in humans, and in single-unit recordings in monkeys, as components of a neural system mediating working memory, which suggests that this system may be activated by the same events that evoke P300.
P300是一种由不频繁出现的目标事件引发的事件相关电位，其振幅取决于紧接在前的刺激序列所提供的背景，这表明它依赖于工作记忆。我们使用对血氧水平敏感的磁共振成像序列，来识别在一个通常用于诱发P300的任务中呈现的不频繁视觉目标刺激所引发的区域变化。目标刺激在目标开始后1.5秒内开始，在4.5至6秒之间达到峰值，在双侧额中回、顶下叶以及后扣带回下缘附近诱发短暂的事件相关激活。在先前对人类的神经影像学研究以及对猴子的单神经元记录中，这些区域已被确定为介导工作记忆的神经系统的组成部分，这表明该系统可能被诱发P300的相同事件所激活。
