NEURAL BASIS OF ENDOGENOUS POTENTIALS IN HUMANS

认知任务期间的EEG和单位活动将从 人内侧颞叶（MTL：海马、海马旁回和 杏仁核）。 电极植入2至5周，以定位 一个癫痫病灶 大事件相关电位（ERP）与相似任务 相关性和潜伏期范围，因为头皮N2，P3和N4已经 在MTL中识别，其中它们具有不同的电压拓扑。 MTL-N2和P3较大，以不经常参加的活动。 MTL-N4是 记录在口头处理，并下降幅度的话， 它们在延迟之后被重复。 这些和其他MTL-ERP组件将在 以其深度地形为基础，辅以同步单元 录音. 听觉辨别、单词识别和相关任务 差异性地影响MTL-ERP的潜伏期和/或振幅 组件，将被用来帮助区分，然后表征这些 件. MTL-P3和-N4可能是在MTL内生成的。 他们与头皮ERP的关系将在任务，患者， 单一的审判。 MTL-ERPs向头皮的可能容量传导 将通过：单侧ATL前后的头皮ERP记录进行评估 为缓解癫痫发作和可能有MTL损伤的遗忘症患者而切除 记录从新皮层和额边缘网站;和比较的 MTL-ERP成分与MTL癫痫样的相对头皮衰减 棘波复合体 整个海马的详细ERP分布 板层，来自单个生理学鉴定的海马的单位记录 神经元，并在东莨菪碱或纳洛酮下的头皮ERPs的变化将是 结合以帮助定义可能的MTL-ERP突触发生器 件. 将进一步检查单元记录，以寻找以下证据： 突触激活的特异性。 这些研究将有助于确定认知的神经基础 活动，特别是在最近的记忆，并评估的有效性， 提出了ERP成分的动物模型。 头皮/深度事件相关电位的研究 相关性可能导致MTL突触的非侵入性监测， 潜在的强大工具，了解正常的神经基础， 衰老和神经系统疾病。

EEG and unit activity during cognitive tasks will be recorded from the human Medial Temporal Lobe (MTL: hippocampus, parahippocampal gyrus, and amygdala). Electrodes are implanted for 2 to 5 weeks in order to localize a seizure focus. Large Event-related Potentials (ERPs) with similar task correlates and latency ranges as the scalp-N2, P3 and N4 have been identified in the MTL where they have distinct voltage topographies. MTL-N2 and P3 are larger to infrequent attended events. The MTL-N4 is recorded during verbal processing, and declines in amplitude to words as they are repeated after a delay. These and other MTL-ERP components will be further distinguished on the basis of their depth topography, supplemented by simultaneous unit recordings. Auditory discrimination, word recognition, and related tasks that differentially affect the latency and/or amplitude of MTL-ERP components, will be used to help distinguish and then characterize these components. The MTL-P3 and -N4 are probably generated within the MTL. Their relationship to scalp-ERPs will be evaluated across tasks, patients, and single trials. Possible volume-conduction of MTL-ERPs to the scalp will be evaluated by: scalp-ERP recordings before and after unilateral ATL removal for seizure relief and in amnesics with probable MTL damage; ERP recordings from neocortical and fronto-limbic sites; and comparison of the relative scalp attenuation for MTL-ERP components versus MTL epileptiform spike-wave complexes. Detailed ERP distribution across hippocampal laminae, unit recordings from single physiologically identified hippocampal neurons, and changes in scalp-ERPs under scopolamine or naloxone will be combined to help define possible synaptic generators of MTL-ERP components. Unit recordings will be further examined for evidence of specificity in synaptic activation. These studies will be useful for defining the neural basis of cognitive activity, especially in recent memory, and for evaluating the validity of proposed animal models of ERP components. Studies of scalp/depth ERP correlations may lead to noninvasive monitoring of MTL synapses, a potentially powerful tool for understanding the neural basis of normal aging and of neurological disease.