Contributions of prefrontal and extrastriate cortex to the event-related potential index of attention

项目摘要 注意力通过增强视觉处理和抑制分散注意力的信息来改善行为。 对视觉注意的神经机制的研究在很大程度上依赖于大脑皮层中一个关键的事件相关电位。 脑电图（EEG）称为N2PC。N2pc可靠地指示注意力在哪里以及何时 分配。N2pc在人类中发现，在猕猴中观察到。神经元的起源 N2PC是未知的。一些研究者认为，纹外视区V4是主要的视区。 N2PC的贡献者。然而，虽然V4显示了一些对注意力的最明显的反应， 选择在枕叶皮层，它不是唯一的区域这样做。此外，并发EEG和单单位 额叶眼区（FEF）的记录显示，前额叶神经元在注意选择之前就表明了注意选择。 N2PC会在头皮上出现考虑到FEF和V4之间广泛的解剖学联系，V4可以 根据来自FEF的反馈产生N2pc。这一假设从未被验证过，因此， 这个项目的目标是阐明N2pc的神经起源。我将检验V4活动可以 N2pc（目的1）和FEF是这种注意信号的发起者的假设（目的2）。目的 1例将通过视觉期间V4区的层流记录与颅外EEG同时进行处理 搜索我将使用这些数据来确定V4活动是否可以通过估计N2pc来贡献。 净突触去极化之间的关系（即，电流源密度）和EEG信号。 此外，我将使用跨V4层测量的电流偶极子对EEG进行正向建模，以研究 在N2PC生成中的作用。目标2将通过可逆灭活V4和FEF来解决，以测试是否或 N2pc无法在这些因果操纵中幸存下来。这些研究的结果将提供明确的答案 最常用的生物物理注意力指标之一的神经发生器。主 本建议的培训目标是获得所需技能集的专业知识， 和动物神经生理学这将包括获得相关文献的专业知识，学习多站点， 多通道层状记录技术，学习执行EEG，并学习执行可逆 灭活研究。所有这些都将通过我的共同赞助人亚历山大梅尔博士和 杰弗里·伍德曼（Geoffrey Woodman）以及我的顾问合作者杰弗里·沙尔（Jeffrey Schall）博士、约翰·雷诺兹（John Reynolds）博士和豪尔赫·里埃拉（Jorge Riera）博士。

PROJECT SUMMARY Attention improves behavior by enhancing visual processing and suppressing distracting information. Research into neural mechanisms of visual attention relies heavily upon a key event-related potential in the electroencephalogram (EEG) known as the N2pc. The N2pc reliably indicates where and when attention is allocated. Discovered in humans, the N2pc has been observed in macaque monkeys. The neuronal origins of the N2pc are unknown. Several investigators have suggested that extrastriate visual area V4 is the main contributor to the N2pc. However, while V4 shows some of the most pronounced responses to attentional selection in occipital cortex, it is not the only area to do so. Moreover, concurrent EEG and single-unit recordings in the frontal eye field (FEF) revealed that prefrontal neurons indicate attentional selection before the N2pc manifests on the scalp. Given the extensive anatomical connections between FEF and V4, V4 could generate the N2pc consequent to feedback from FEF. This hypothesis has never been tested, so the research goal of this project is to elucidate the neural origins of the N2pc. I will test the hypothesis that V4 activity can contribute to the N2pc (Aim 1) and the hypothesis that FEF is the initiator of this attentional signal (Aim 2). Aim 1 will be addressed through laminar recordings of area V4 concurrent with extracranial EEG during visual search. I will use these data to determine whether V4 activity can contribute to the N2pc by estimating the relationship between net synaptic depolarizations (i.e., Current Source Density) and the EEG signal. Furthermore, I will forward model the EEG using the current dipoles measured across V4 layers to investigate their role in N2pc generation. Aim 2 will be addressed by reversibly inactivating V4 and FEF to test whether or not the N2pc survives these causal manipulations. The outcome of these studies will provide definitive answers about the neural generators of one of the most commonly used biophysical indicators of attention. The primary training objective of this proposal is to attain expertise in the required skill set, bridging between human EEG and animal neurophysiology. This will include gaining expertise in the relevant literature, learning multi-site, multi-channel laminar recording techniques, learning to perform EEG, and learning to perform reversible inactivation studies. All of this will be guaranteed via mentorship by my co-sponsors Drs. Alexander Maier and Geoffrey Woodman as well as my advisory collaborators Drs. Jeffrey Schall, John Reynolds, and Jorge Riera.