Cortical mechanisms of categorical perceptual learning

描述(由申请人提供)：虽然感官刺激可能在其物理维度上连续变化，但它们所代表的行为重大事件通常是离散的。为了表示这些离散的事件，感觉系统需要将连续的刺激空间映射成离散的感觉感知。例如，波长逐渐变化的光被认为具有离散的色调/颜色。这种现象被称为绝对知觉。类别知觉背后的神经机制尚不清楚。范畴知觉可以通过知觉训练获得。我们建议研究范畴知觉学习如何改变听觉皮质的感觉加工，以阐明范畴知觉学习的机制。 以前的研究表明，感觉经验扩大了对经验刺激的大脑皮层表征，并形成了对刺激的分类知觉。我们的初步计算分析进一步表明，具有放大的皮质表征的刺激可以被明确地感知到。基于这些结果，我们建议检验扩大的皮质表征是范畴声音知觉的一种机制的假设。这项研究的长期目标是了解范畴声音表征和学习背后的神经机制。具体地说，我们建议(1)训练动物进行知觉辨别和分类任务，并确定训练如何有助于分类声音表征；(2)电生理检查行为训练动物的听觉皮质并量化学习诱导的可塑性效应；(3)使用计算方法确定观察到的大脑皮层可塑性效应将如何影响知觉行为，然后将其与动物表现出的行为学习进行比较。这项拟议的研究将提供对感觉分类的复杂过程的见解。 与公共健康相关：能够对感官信息进行分类对于我们的语言交流、音乐欣赏和视觉识别至关重要。这项拟议的研究旨在了解我们是如何学习对新的感觉信息进行分类的。这项拟议的研究结果将为如何改善学习提供新的启示。

DESCRIPTION (provided by applicant): While sensory stimuli may vary continuously along their physical dimensions, the behaviorally significant events that they represent are often discrete. To represent those discrete events, the sensory system needs to map the continuous stimulus spaces into discrete sensory percepts. Lights of gradually changing wavelength, for instance, are perceived as having discrete hues/colors. This phenomenon is named categorical perception. The neural mechanisms underlying categorical perception are unknown. Categorical perception can be acquired through perceptual training. We proposed to investigate how categorical perceptual learning alters sensory processing in the auditory cortex to elucidate the mechanisms of categorical perceptual learning. Previous studies have shown that sensory experience enlarges cortical representations of the experienced stimuli and shapes categorical perception of the stimuli. Our pilot computational analyses further indicate that stimuli with enlarged cortical representations may be categorically perceived. Based on these results, we propose to test the hypothesis that enlarged cortical representation is a mechanism for categorical sound perception. The long-term goal of the proposed research is to understand the neural mechanisms underlying categorical sound representation and learning. Specifically, we propose to (1) train animals in perceptual discrimination and categorization tasks and determine how the training contribute to categorical sound representations, (2) electrophysiologically examine the auditory cortex of the behaviorally trained animals and quantify learning-induced plasticity effects, and (3) determine using computational methods how the observed cortical plasticity effects would impact perceptual behaviors, which will then be compared with the behavioral learn shown by the animals. The proposed research will provide insights into the complex processes of sensory categorization. PUBLIC HEALTH RELEVANCE: Being able to categorize sensory information is vital for our speech communication, music appreciation and visual recognition. The proposed research aims at understanding how we learn to categorize new sensory information. The results of the proposed research will shed new light on how to improve learning.