A1 neural basis of frequency discrimination learning

A1 鉴频学习的神经基础

• 批准号: 6883940
• 负责人: David T Blake
• 金额: $ 5.42万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6883940
• 关键词: Aotus; auditory cortex; auditory discrimination; auditory feedback; auditory stimulus; behavior test; conditioning; discrimination learning; implant; microelectrodes; neural plasticity; operant conditionings; sound perception; stimulus /response

DESCRIPTION (provided by applicant): This application outlines a direct study of the mechanisms of auditory learning. Animals are capable of making new associations between positive reinforcers, the sensory context that preceded them, and the motor acts that cause them. The proposed studies will use multiple microelectrode implant technology to record simultaneously from a large number of neurons in auditory cortex throughout a period in which an animal acquires a new association. The specific intent will be to observe how the auditory cortex representation of the sensory context is altered by the learning. The monkeys will be trained to discriminate short sound tones. As they begin to perform the task to receive rewards, their brain learning machinery is engaged and causes unavoidable changes in how sounds are represented. Data will be collected in parallel, in terms of the animal's perceptual capabilities and the response properties of neurons in auditory fields within and outside the behavioral tasks. The use of implants in neural systems has advanced much in the last decade; this study will apply that technology to study learning. In the first phase of training, animals will respond to short tones that are just higher in frequency than fixed comparison tones. Preliminary studies have shown that if the target stimulus comes from a fixed range, the representation of that frequency range grows and intensifies. After this initial phase, the animals will perform the same frequency discrimination task using randomized frequencies for comparison and target tone pips. A control experiment will replicate the trials of the first phase of training in naive animals that are only passive listeners. These studies should contribute to defining the plastic properties of cortical fields as dynamic learning neural networks. Such networks are most easily understood in terms of their initial sets of connections and their learning rules. This study will isolate and test different hypotheses for learning rules, and will lead to a greater understanding of the adaptive role of the cerebral cortex in general, both in instrumental learning and in classical conditioning.

描述（由申请人提供）：本申请概述了听觉学习机制的直接研究。动物能够在积极强化物、之前的感官环境以及引起它们的运动行为之间建立新的联系。拟议的研究将使用多个微电极植入技术，在动物获得新关联的整个时期内同时记录听觉皮层中大量神经元的数据。具体目的是观察学习如何改变听觉皮层对感觉环境的表征。猴子将接受训练来辨别短音。当他们开始执行任务以获得奖励时，他们的大脑学习机制就会启动，并导致声音的表示方式发生不可避免的变化。数据将同时收集，包括动物的感知能力以及行为任务内外听觉场神经元的反应特性。神经系统植入物的使用在过去十年中取得了很大进展。这项研究将应用该技术来研究学习。在训练的第一阶段，动物将对频率仅高于固定比较音调的短音做出反应。初步研究表明，如果目标刺激来自固定范围，则该频率范围的表现会增长并增强。在这个初始阶段之后，动物将使用随机频率进行相同的频率辨别任务以进行比较和目标音调。对照实验将在天真的动物中复制第一阶段的训练试验，这些动物只是被动的倾听者。这些研究应该有助于将皮质区域的可塑性定义为动态学习神经网络。这种网络最容易理解的是它们的初始连接集和学习规则。这项研究将分离和测试学习规则的不同假设，并将导致人们更好地理解大脑皮层在器乐学习和经典条件反射中的一般适应性作用。