EFFECTS OF LEARNING ON SPEECH REPRESENTATION IN AUDITIORY CORTEX

学习对听觉皮层言语表征的影响

• 批准号: 6663431
• 负责人: CHRISTOPH SCHREINER
• 金额: $ 20.73万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6663431
• 关键词: Saimiri; animal communication behavior; auditory cortex; auditory discrimination; behavior test; behavioral /social science research tag; biological signal transduction; cerebral cortex; electrophysiology; ethology; histochemistry /cytochemistry; learning; neural information processing; neural plasticity; neurons; neuropsychology; operant conditionings; sensorimotor system; single cell analysis; sound; speech

The primary auditory cortex (AI) of mammals shows several superimposed functional organizations when explored with simple signals such as pure tones. Basic spatial organizations have been described now for stimulus frequency, bandwidth, spectral envelope, frequency modulation, latency, response threshold, and binaural interaction. The consequences of these organizations for the cortical representation of complex signals, in particular elemental speech signals, is of special interest since similar principles may provide the basis for the perception and categorization of speech in humans. The representational principles will be explored with elemental speech signals in AI of speech squirrel in AI of squirrel (Saimiri sciureus) naive to the sounds and animals that have acquired behavioral affinity to the signals. The behavioral relevance of the studied complex signals will be established by engaging the animals in a psychophysical task of signal discrimination and generalized classification. The task will be performed under varying stimulus and environmental conditions such as by using different stimulus intensities, fundamental frequencies, and to utilize generalized classification schemes that operate independent from signal level and background conditions, thus approaching human discrimination and classification abilities. Determining the cortical encoding of elemental speech sounds on conjunction with reverse-correlation analysis of spectro-temporal receptive fields in naive and highly trained animals will illuminate basic attributes of complex signal representations as well the refinement of coding attributes with learning to discriminate and classify the signals. Recording of cortical activity from animals while they are being trained to discriminate speech sounds will let us follow the time course of plastic changes and establish physiological correlates of perceptual discrimination and detection thresholds. The emergence of refined spatial-temporal patterns of cortical activity by learning-induced plasticity and their relationship to perceptual capacities of the animals provides a basic cellular model of speech sound representation.

哺乳动物的主要听觉皮层（AI）在使用简单信号（例如纯音）进行探索时，显示了几个叠加的功能组织。现在已经描述了基本的空间组织，用于刺激频率，带宽，光谱包络，频率调制，延迟，响应阈值和双耳相互作用。这些组织对复杂信号的皮质表示，特别是元素语音信号的后果具有特别的兴趣，因为类似的原则可能为人类对语音的感知和分类提供了基础。代表原理将在Squirrel AI（Saimiri Sciureus）中的语音松鼠中的元素语音信号探索，这些声音对获得了对信号的行为亲和力的声音和动物天真。研究复合信号的行为相关性将通过使动物参与信号歧视和广义分类的心理物理任务来确定。该任务将在不同的刺激和环境条件下执行，例如使用不同的刺激强度，基本频率，并利用与信号水平和背景条件独立运行的广义分类方案，从而接近人类的歧视和分类能力。 确定元素语音的皮质编码与幼稚和高度训练的动物中光谱式接受场的逆相关分析，将阐明复杂信号表示的基本属性，以及与学习属性进行编码属性的完善，从而歧视和对信号进行分类。记录动物的皮质活动时，他们正在接受训练以区分语音的训练，这将使我们遵循塑料变化的时间过程，并建立感知歧视和检测阈值的生理相关性。通过学习诱导的可塑性及其与动物感知能力的关系，皮质活性的精致时空模式的出现提供了语音表达的基本细胞模型。