ATTENTION, ORIENTATION AND HUMAN PREFRONTAL CORTEX

P300事件相关电位，即所谓的“决策波”，是 当注意到不常见的环境时生成 事件。P300广泛应用于临床和基础 对人类认知做出推论的心理学研究。 因此，P300的神经起源是相当重要的 引起认知神经学家和临床医生的兴趣。 我们实验室的研究表明，单侧病变在 前额叶或颞顶联合皮质可减少或 取消听觉P300的组成部分。各种各样的证据， 包括来自海马体结构的脑部记录， 提示边缘结构在P300世代中起重要作用。 灵长类动物的神经解剖学研究证明了相互作用 前额叶和颞顶皮质之间的联系 可以调节海马体的功能。头皮P300可以索引 这一联合皮质-海马区回路的参与， 在生物检测和编码过程中被激活 明显的刺激。 提出了一系列研究来调查这些贡献。 大脑皮层和海马区与P300代的关联。群组 前额叶或后叶局灶性脑梗塞的患者 联合皮质，或后海马区梗死 将会被研究。分级平行检测实验 难度较大的表演将在听觉、视觉和 躯体感觉模式。高分辨率核磁共振神经成像将 用于重建所有患者的病变范围，并 评估P300发生器可能的特定于医疗模式的元素 电路。反应时间和响应的并发分析 准确度将被用来描述认知伴随 在P300异常中。设计了建议的研究计划。 提供关于神经和行为底物的系统数据 在P300中。

A P300 event-related potential, the so-called "decision wave", is generated when attention is drawn to infrequent environmental events. The P300 is widely used in clinical and basic psychological research to draw inferences about human cognition. Therefore, the neural origin of the P300 is of considerable interest to cognitive neuroscientists and clinicians. Studies in our laboratory have shown that unilateral lesions in prefrontal or temporal-parietal association cortex can reduce or abolish components of the auditory P300. A variety of evidence, including intracranial recordings from hippocampal formation, suggests an important role of limbic structures in P300 generation. Neuroanatomical studies in primates have documented reciprocal connections through which prefrontal and temporal-parietal cortex could modulate hippocampal function. The scalp P300 may index the engagement of this association cortex-hippocampal circuit, which is activated during the detection and encoding of biologically significant stimuli. A series of studies is proposed to investigate the contributions of association cortex and hippocampus to P300 generation. Groups of patients with focal infarctions of prefrontal or posterior association cortex, or infarctions of the posterior hippocampus will be studied. Parallel detection experiments with graded levels of difficulty will be performed in auditory, visual and somatosensory modalities. High resolution MRI neuroimaging will be used to reconstruct lesion extent in all patients, and to evaluate possible modality-specific elements of P300 generator circuits. Concurrent analyses of reaction times and response accuracy will be used to characterize the cognitive concomitants of the P300 abnormalities. The proposed research plan is designed to provide systematic data on the neural and behavioral substrates of the P300.