Spatiotemporal patterns of neural activity and their role in perception

神经活动的时空模式及其在感知中的作用

• 批准号: 10165724
• 负责人: JOHN H REYNOLDS
• 金额: $ 46.18万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10165724
• 关键词: Affect; Algorithms; Alzheimer' s Disease; Anesthesia procedures; Animals; Area; Arousal; Attention; Axon; Behavior; Brain; Brain Diseases; Brain region; Callithrix; Callithrix jacchus jacchus; Cohort Effect; Computer Models; Computing Methodologies; Cues; Data; Detection; Discrimination; Electrodes; Exhibits; Failure; Fire - disasters; Human; Implant; Individual; Injections; Link; Location; Measurement; Measures; Methods; Modeling; Monkeys; Motion; Neurons; Perception; Performance; Phase; Positioning Attribute; Primates; Probability; Property; Recurrence; Reporting; Research Personnel; Role; Sampling; Schizophrenia; Sensory; Signal Transduction; Source; Stimulus; Sum; Surface; Synapses; Syncope; Testing; Time; Training; Travel; Utah; Visual; Visual Cortex; Visual Perception; area MT; area V1; autism spectrum disorder; awake; expectation; improved; microsystems; neocortical; network models; neural patterning; neuroregulation; novel; predictive modeling; relating to nervous system; response; retinotopic; sample fixation; spatiotemporal; visual stimulus

Project Summary/Abstract The ability for an animal or human to perceive a subtle environmental stimulus is not a fixed parameter. Rather, perceptual thresholds fluctuate with changes in arousal, attention, and expectation. Similarly, individual neurons within the visual cortex exhibit variable responses when repeatedly presented the same stimulus, an observation widely thought to contribute to perceptual variability. However, injection of identical noisy currents evokes highly precise spike trains, indicating that these fluctuations are not due to a noisy spiking mechanism. Instead, it largely reflects moment-by-moment synaptic input from the cortical network. These network fluctuations are reflected in local field potentials (LFPs). Here, new computational methods have been used to show for the first time that spontaneous fluctuations are organized into traveling waves in awake, behaving primates. These methods enable tracking of traveling waves on a moment-by-moment basis, without trial averaging analyses. Spontaneous waves create periods of both elevated and suppressed spiking activity, and preliminary data indicate that they modulate stimulus-evoked spiking responses and perceptual sensitivity in a visual detection task. Thus, the assembled team is well positioned to understand the role of neocortical traveling waves in perception and propose three Aims. Aim 1: Test whether spontaneous activity in awake marmoset MT and V1 is organized into traveling waves. Utah arrays will be implanted in marmoset area MT and V1 to record spikes and LFPs while the monkey fixates a blank screen. Network fluctuations will be detected to test the hypothesis that spontaneous spiking activity generates traveling waves that can be detected in the LFP, and the phase of LFP fluctuations reflect periods of depolarization and hyperpolarization. Aim 2: Develop a spiking network model linking LFP waves, spiking activity and perception. A preliminary computational model has been developed that accounts for spike-LFP relationships observed in experimental data. Here, the model will be extended to quantitatively match properties of observed traveling waves, and then used to generate testable predictions about how the phase of LFP waves affects spiking probability, stimulus-evoked responses, and perceptual sensitivity (the latter by extending the model within an ideal observer framework). Aim 3: Determine the impact of traveling waves on sensory perception. The model predicts that spontaneous traveling waves will both increase and decrease the gain of a stimulus-evoked response, depending on wave phase. To test this, spontaneous waves will be recorded within MT and V1 as marmosets attempt to detect a faint visual stimulus. This will also allow researchers to test the model prediction that wave phase regulates perceptual sensitivity. Together, these analyses will help characterize the contributions of spontaneous traveling waves to cortical variability and perception, information critical for understanding brain disorders associated with failures in perception and attention, such as autism, schizophrenia, and Alzheimer’s disease.

项目概要/摘要 动物或人类感知微妙环境刺激的能力不是一个固定参数。 相反，知觉阈值会随着唤醒、注意力和期望的变化而波动。 当重复出现相同的刺激时，视觉皮层内的神经元表现出不同的反应， 普遍认为观察会导致感知变异，然而，注入相同的噪声电流。 引起高度精确的尖峰序列，表明这些波动不是由于嘈杂的尖峰机制造成的。 相反，它在很大程度上反映了来自皮质网络的每时每刻的突触输入。 波动反映在局部场势（LFP）中，这里使用了新的计算方法。 首次表明自发波动在清醒时被组织成行波，表现 这些方法无需尝试即可实时跟踪行波。 平均分析产生了尖峰活动升高和抑制的时期，以及 初步数据表明，它们调节刺激引起的尖峰反应和知觉敏感性 因此，组建的团队能够很好地理解新皮质的作用。 感知中的行波并提出三个目标 目标 1：测试清醒时是否有自发活动。 狨猴MT和V1被组织成行波犹他阵列将被植入狨猴MT区域。 当猴子注视空白屏幕时，V1 会记录尖峰和 LFP 网络波动。 检测到测试自发尖峰活动产生行波的假设，该行波可以 在 LFP 中检测到，LFP 波动的相位反映了去极化和超极化的周期。 目标 2：开发一个连接 LFP 波、尖峰活动和感知的尖峰网络模型。 已经开发出计算模型来解释实验中观察到的尖峰 LFP 在这里，该模型将扩展到定量匹配观测到的行波的特性，以及 然后用于生成有关 LFP 波的相位如何影响尖峰概率的可测试预测， 刺激诱发的反应和知觉敏感性（后者通过在理想的范围内扩展模型来实现） 目标 3：确定行波对感官知觉的影响。 预测自发行波将增加和减少刺激诱发的增益 响应，取决于波相位 为了测试这一点，自发波将在 MT 和 V1 内记录为 狨猴试图检测微弱的视觉刺激，这也将使研究人员能够测试模型的预测。 这些分析将有助于表征相位波调节感知灵敏度。 自发行波对皮质变异和感知的贡献，信息对 了解与感知和注意力缺陷相关的大脑疾病，例如自闭症， 精神分裂症和阿尔茨海默病。