Functional consequences of rapid adaptation

描述(由申请人提供)：适应--对最近的刺激反应的敏感度的变化--是神经系统中普遍存在的过程。长期以来，人们一直在理论上认为，适应应该通过提高神经编码的效率来增强感知。虽然有足够的神经生理学支持这一观点，但很难找到适应的功能后果的行为证据，特别是在简短的、潜在的功能相关的时间尺度上。我建议使用心理物理学、计算模型和经颅磁刺激(TMS)来研究适应诱导的短暂运动刺激表征的变化。这项工作将结合行为学和生理学文献来阐明快速适应的机制及其后果。在目标1(心理物理学和计算模型)中，我将检验这样一个假设，即快速知觉适应会在观察者对短暂运动刺激的感知中引入系统性错误。在试点研究中，我发现了一种新的感知现象，在这种现象中，观察者可靠地感觉到大的、高对比度的刺激与实际刺激运动的方向相反(即，向左的刺激始终被报告为向右移动)。使用一个简单的计算模型，我已经确定了一个可能的解释：该模型表明，随着时间的推移，适应会导致虚假的双相运动对抗信号。负叶是向相反方向运动的信号，这可能解释了观察者相反的感知。我计划将这些预测与其他模型的预测进行比较。在目标2(经颅磁刺激)中，我将对�预测的模型进行实证检验。通过传递单个脉冲 在不同的刺激起始异步值(SOA)下，我可以恢复观察者对简短运动刺激的时间积分窗口。在低对比度下，该模型预测TMS将持续损害观察者在整个SOA中的感知。然而，在高对比度下，假设的双相反应预测早期的TMS(短的SOA)会削弱感知，而晚期的TMS(长的SOA)会改善感知。在此期间，我将通过与我的研究导师、更广泛的纽约大学神经科学界的互动和正式课程，接受行为、计算和认知神经科学方法方面的培训。拟议的研究完全符合NEI的使命。它调查适应，一个重要的“视觉功能机制”(NEI使命声明)。此外，由于适应是神经系统的一般特性，建议在健康观察者中进行的研究很容易适用于特殊人群中的翻译研究，并可能澄清先前观察到的老年人以及患有精神分裂症、严重抑郁症和自闭症的个人的知觉差异。

DESCRIPTION (provided by applicant): Adaptation - changes in sensitivity in response to recent stimulation - is a ubiquitous process in neural systems. It has long been theorized that adaptation should enhance perception by improving the efficiency of the neural code. While there is ample neurophysiological support for this idea, it has been difficult to find behavioral evidence of the functional consequences of adaptation, especially on brief, potentially functionally relevant timescales. I propose to use psychophysics, computational modeling, and transcranial magnetic stimulation (TMS) to investigate adaption-induced changes in the representation of brief moving stimuli. This work will bring together the behavioral and physiology literature to clarify the mechanisms of rapid adaptation and their consequences. In Aim 1 (Psychophysics and Computational Modeling), I will test the hypothesis that rapid perceptual adaptation introduces systematic errors in observers' perception of brief motion stimuli. In pilot studies, I have identified a novel perceptual phenomenon in which observers reliably perceive large, high contrast stimuli as moving in the opposite direction of the actual stimulus motion (i.e. a leftward stimulus is consistently reported as moving rightward). Using a simple computational model, I have identified a potential explanation: the model suggests that adaptation induces a spurious biphasic motion opponent signal over time. The negative lobe, signaling motion in the opposite direction, may account for observers' reversed percepts. I plan to compare these predictions with those made by alternative models. In Aim 2 (Transcranial Magnetic Stimulation), I will empirically test the models� predictions. By delivering single pulses of TMS at varying stimulus onset asynchronies (SOAs), I can recover observers' temporal integration window for brief motion stimuli. At low contrast, the model predicts that TMS will consistently impair observers' perception across SOAs. However, at high contrast, the hypothesized biphasic response predicts that early TMS (short SOA) will impair perception, but late TMS (long SOA) will improve perception. During this fellowship, I will receive training in behavioral, computational, and cognitive neuroscience methods through interactions with my research mentor, the broader NYU neuroscience community, and formal coursework. The proposed research is fully in line with the NEI mission. It investigates adaptation, an important "mechanism of visual function" (NEI Mission Statement). Further, as adaptation is a general property of neural systems, the proposed research in healthy observers is readily applicable to translational research in special populations, and may clarify previously observed perceptual differences in older adults as well as individuals with schizophrenia, a history of major depression, and autism.