NEURAL BASIS OF ENDOGENOUS POTENTIALS IN HUMANS

认知任务期间的脑电和单位活动将从 人的内侧颞叶(MTL：海马区、海马区旁回和 杏仁核)。植入电极2至5周，以便定位 癫痫发作的焦点。具有类似任务的大事件相关电位(ERP) 与头皮的相关性和潜伏期范围--n2、p3和n4 在MTL中确定，它们具有不同的电压拓扑图。 对于不经常参加的事件，MTL-N2和P3较大。MTL-N4是 在言语处理过程中被记录，并在幅度上下降到单词，如 它们在延迟一段时间后重复。 这些组件和其他MTL-ERP组件将在 以深度地形为基础，辅以同步单位 录音。听觉辨别、单词识别和相关任务 对MTL-ERP潜伏期和/或波幅有不同影响 组件，将用来帮助区分和表征这些 组件。MTL-P3和-N4可能是在MTL内生成的。 它们与头皮ERPs的关系将在不同的任务、患者、 和单项试验。MTL-ERPs对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 抽搐解除和遗忘者可能有MTL损伤；事件相关电位 来自新皮质和额叶边缘部位的记录；以及 MTL-ERP成分与MTL癫痫样的头皮相对衰减 棘波复合波。事件相关电位在海马区的详细分布 来自单个生理学鉴定的海马层的单位记录 神经细胞和头皮-ERPs在东莨菪碱或纳洛酮作用下的变化 结合以帮助确定MTL-ERP的可能突触生成器 组件。将进一步检查单位的录音，以寻找证据 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，尤其是在最近的记忆中，并用于评估 提出了ERP组件的动物模型。头皮/深度ERP的研究 相关性可能导致对MTL突触的非侵入性监测， 理解正常神经基础的潜在有力工具 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.