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

项目总结 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。 对视觉注意神经机制的研究在很大程度上依赖于大脑中一种关键的事件相关电位 被称为N2PC的脑电(EEG)。N2PC可可靠地显示何时何地受到关注 已分配。在人类中发现了N2PC，在猕猴身上也观察到了N2PC。神经起源的研究进展 N2PC是未知的。一些研究人员认为纹外视区V4是主要的 N2PC的贡献者。然而，虽然V4显示了对注意的一些最明显的反应 选择枕叶皮质，并不是唯一这样做的区域。此外，并发脑电和单次脑电 前额叶视野(FEF)的记录显示，前额叶神经元以前表明注意选择 N2PC出现在头皮上。鉴于FEF和V4之间广泛的解剖联系，V4可能 根据FEF的反馈生成N2PC。这一假设从未被检验过，所以这项研究 本项目的目标是阐明N2PC的神经起源。我将测试V4活动可以 有助于N2pc(目标1)和FEF是该注意信号的发起者的假设(目标2)。目标 1将通过在视觉期间同时进行颅外脑电的V4区的层状记录来寻址 搜索。我将使用这些数据来确定V4活动是否可以通过估计 净突触去极化(即电流源密度)与脑电信号之间的关系。 此外，我将使用跨V4层测量的当前偶极子对EEG进行正向建模以进行研究 他们在N2PC生成中的作用。目标2将通过可逆地停用V4和FEF来解决，以测试是否或 N2PC没有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。 关于神经生成器的一个最常用的生物物理指标值得关注。初级阶段 这项建议的培训目标是获得所需技能集的专业知识，在人类脑电之间架起桥梁 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， 多通道层流记录技术，学习进行脑电，并学习进行可逆操作 失活研究。所有这一切都将通过我的共同赞助人Alexander Maier博士和 杰弗里·伍德曼以及我的顾问合作者杰弗里·舒尔博士、约翰·雷诺兹博士和豪尔赫·里埃拉。

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.