NEURAL BASIS OF ENDOGENOUS POTENTIALS IN HUMANS

流经活跃的大脑突触的电流可能会相加而产生 诱发电位(EP)和磁场，可记录在一个 距离。因此，认知EP组件可以用来监控 正常和疾病受试者脑突触的非侵入性活动 正如他们所想的那样。最终，认知诱发电位可能被用来识别 信息处理的性质、顺序、持续时间和强度 包括感知、记忆和语言的各个阶段。目前，这样的 认知诱发电位因其突触而应用受限 发电机是未知的。本地化EP的唯一明确方法 发电机是从内部直接记录的发电结构。 目前的赠款建议对患有 抗惊厥药物多年后仍未得到控制的癫痫发作 治疗。植入电极是为了定位 致痫组织，从而指导手术切除。而当 在等待自发性发作之前，患者可能会同意进行 当他们的大脑脑电被监测时，他们的认知任务。水深 记录将从植入的大电极获得 枕叶、顶叶、颞叶、枕叶和额叶皮质，以及 边缘系统(杏仁核、海马结构和扣带回)， 在唤起各种认知EP成分的任务中，包括：(1) 不常见的听觉、视觉或视觉诱发的N1abc/P2/MMN/N2/P3a/P3b/Sw 体感刺激；和(2)P75/N125/P170/N230/N310/N460/P620/Slow 由面孔和词语以及它们的组成部分引起的波动。任务 变异将被用来以不同的方式唤起脸部的连续阶段 以及用于表征相关联的EP的单词识别 组件。对于每个组成部分，记录地点将被分类为： (1)焦点发生器，其中分量相对于相邻分量较大 结构，并且其幅度在连续的 导线，并可能反转；(2)可能的扩散发电机，其中 灰质中的电压梯度可能较小，但明显较大 在紧靠其下的白质中，以及(3)远离脑白质 生成结构。将使用层流记录来更好地定义 震源发生器内的电流源和电流汇。这种可能性 本地产生的EP传播到头皮的测试将由 记录治疗性皮质-边缘切除手术前后的数据。全 录音将使用基于MRI的有限差分进行解释 EP传播的计算模型。总括而言，拟议的研究 将加深和拓宽我们对人类认知诱发电位的认识。这 将允许：可使用头皮测试的集成神经认知模型 正常受试者的录音.动物的精确验证标准 认知诱发电位模型，导致基础神经生理学研究；以及 使用头皮诱发电位对特定突触系统进行直接功能测试 患有神经或精神疾病的患者。

Current flowing across active brain synapses may summate to produce Evoked Potentials (EPs) and magnetic fields which can be recorded at a distance. Thus, cognitive EP components may be used to monitor the activity of brain synapses noninvasively in normal and diseased subjects as they think. Eventually, cognitive EPs may be used to identify the nature, sequence, duration and intensity of the information-processing stages involved in perception, memory, and language. Currently, such applications of cognitive EPs are limited because their synaptic generators are unknown. The only unambiguous method for localizing EP generators is to directly record from within the generating structure. The present grant proposes to perform such recordings in patients with epileptic seizures that remain uncontrolled after years of anticonvulsant treatment. Electrodes are implanted in order to localize the epileptogenic tissue, and thus direct its surgical removal. While awaiting spontaneous seizure onset, the patient may consent to perform cognitive tasks while their intracerebral EEG is monitored. Depth recordings will be obtained from macroelectrodes implanted in the occipital, parietal, temporal, rolandic and frontal cortices, and in the limbic system (amygdala, hippocampal formation and cingulate gyrus), during tasks evoking various cognitive EP components, including: (1) the N1abc/P2/MMN/N2/P3a/P3b/SW evoked by infrequent auditory, visual or somaesthetic stimuli; and (2) the P75/N125/P170/N230/ N310/N460/P620/slow wave evoked by faces and words, and their constituent parts. Task variants will be used to differentially evoke successive stages of face and word recognition for characterization of the associated EP components. For each component, recording sites will be classified into: (1) focal generators, where the component is large relative to adjacent structures, and where its amplitude changes rapidly between successive leads, and may polarity-invert; (2) possible diffuse generators, where the voltage gradient may be small but clearly larger in the grey matter than in immediately subjacent white matter, and (3) distant from the generating structure. Laminar recordings will be used to better define the current sources and sinks within focal generators. The possibility that the locally generated EPs propagate to the scalp will be tested by recording before and after therapeutic cortico-limbic excisions. All recordings will be interpreted using an MRI-based finite difference computational model for EP propagation. Overall, the proposed studies will deepen and broaden our knowledge of cognitive EPs in humans. This will permit: integrated neurocognitive models testable using scalp recordings in normal subjects; precise validation criteria for animal models of cognitive EPs, leading to basic neurophysiological studies; and direct functional tests for specific synaptic systems using scalp EPs in patients with neurological or psychiatric disease.