Neural Mechanisms of Perceptual Learning

感知学习的神经机制

• 批准号: 7678259
• 负责人: Ariel Shalom Rokem
• 金额: $ 2.23万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-01 至 2010-05-21
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7678259
• 关键词: Acetylcholine; Address; Affect; Aging; Alzheimer' s Disease; Amblyopia; Animal Model; Animals; Area; Aricept; Behavior; Behavioral; Brain; Cells; Characteristics; Cholinesterase Inhibitors; Classification; Clinical; Cognition Disorders; Development; Discrimination; Double-Blind Method; Dyslexia; Exhibits; Functional Magnetic Resonance Imaging; Health Benefit; Human; Individual; Intervention; Laboratories; Lateral; Learning; Light; Location; Measurement; Measures; Methods; Modality; Names; Neurons; Noise; Perceptual learning; Performance; Pharmaceutical Preparations; Physiological; Placebo Control; Play; Population; Procedures; Process; Prosopagnosia; Psychophysics; Psychophysiology; Relative (related person); Reporting; Research; Role; Signal Transduction; Specificity; Stimulus; System; Techniques; Testing; Training; Visual; Visual Cortex; Visual Fields; Visual system structure; blood oxygenation level dependent response; cholinergic; donepezil; extrastriate visual cortex; mild neurocognitive impairment; neuromechanism; novel; relating to nervous system; research study; response; sensory cortex; sensory mechanism; skills; stem; young adult

DESCRIPTION (provided by applicant): The proposed research aims to elucidate the neural mechanisms of perceptual learning in the visual modality. Specifically, we aim to discover the loci of learning in the visual system and to describe the computational mechanisms whereby learning occurs. A significant body of research exists on the behavioral consequences of perceptual learning: typically, learning fails to generalize across various physical parameters of the stimulus. For example, if a perceptual discrimination is learned in one part of the visual field, the improvement does not transfer to other parts of the visual field. Thus, learning is assumed to stem from changes occurring in primary sensory mechanisms. However, there is a relative paucity of physiological evidence to explain these phenomena and the underlying neural mechanisms. We will use psychophysical methods in order to track the behavioral consequences of learning in two different visual discriminations, tapping different percpetual mechanisms. Then, we will use fMRI in order to measure learning-induced changes in the spatial extent of responses in visual cortical areas and in the tuning of large populations of cells in these areas. FMRI provides simultaneous recordings from mutliple brain areas. Therefore, it is a suitable method in order to track down the locus of learning in the visual system. Finally, we propose to explore the role of top-down modulation of Perceptual Learning by the cholinergic system. Animal studies show that activity in this system facilitates modality-specific and stimulus-specific perceptual learning. We will test the role of this system in human perceptual learning by administering a cholinesterase inhibitor commonly prescribed as treatment for Alzheimer's Disease (donepezil, trade name: Aricept) during training on a perceptual task. Percpetual training procedures have been suggested to provide health benefits in conditions as varied as dyslexia, amblyopia, congenital prosopagnosia and mild cognitive impairment in aging, but in most cases, the neural mechanisms underlying the training-induced improvements are unknown. Understanding the underpinnings of specific learning will allow the development of more effective clinical interventions in these and other conditions. Understanding the effects of cholinergic modulation on neural substrates of perceptual learning would shed light, not only on the functions of the cholinergic system in healthy individuals, but also on the role this system may have in cognitive disorders, such as Alzheimer's Disease.

描述（由申请人提供）：拟议的研究旨在阐明视觉模态中感知学习的神经机制。具体来说，我们的目标是发现在视觉系统中的学习位点，并描述学习发生的计算机制。一个重要的研究主体存在于知觉学习的行为后果：通常，学习不能概括各种物理参数的刺激。例如，如果在视野的一部分中学习了感知辨别，则改善不会转移到视野的其他部分。因此，学习被认为是源于初级感觉机制的变化。然而，有一个相对缺乏的生理证据来解释这些现象和潜在的神经机制。我们将使用心理物理学的方法，以跟踪学习的行为后果，在两个不同的视觉歧视，挖掘不同的认知机制。然后，我们将使用功能磁共振成像，以测量学习引起的变化，在视觉皮层区域的反应的空间范围和在这些地区的大量细胞的调谐。功能磁共振成像提供了多个大脑区域的同步记录。因此，这是一个合适的方法，以跟踪在视觉系统中的学习轨迹。最后，我们建议探讨胆碱能系统自上而下的调节知觉学习的作用。动物研究表明，在这个系统中的活动促进特定的模式和刺激特定的知觉学习。我们将测试该系统在人类知觉学习中的作用，通过在知觉任务训练期间施用常用于治疗阿尔茨海默病的胆碱酯酶抑制剂（多奈哌齐，商品名：Aricept）。永久性训练程序已被建议提供健康益处的条件，如阅读障碍，弱视，先天性面容失认症和轻度认知障碍的老化，但在大多数情况下，潜在的训练引起的改善的神经机制是未知的。了解特定学习的基础将允许在这些和其他条件下开发更有效的临床干预措施。了解胆碱能调节对知觉学习的神经基质的影响将不仅揭示健康个体中胆碱能系统的功能，而且还揭示该系统在认知障碍（如阿尔茨海默病）中的作用。