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Hemispheric interaction during lateralized auditory processing in humans: effects of task difficulty, training and age

人类侧化听觉处理过程中的半球相互作用：任务难度、训练和年龄的影响

基本信息

批准号：
192660229
负责人：
Dr. Nicole Angenstein
金额：
--
依托单位：
Combinatorial NeuroImaging Core Facility (CNI)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2011
资助国家：
德国
起止时间：
2010-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/192660229?language=en
关键词：
Hemispheric interaction during lateralized auditory

项目摘要

The left and the right auditory cortex are differentially specialized for the processing of fundamental acoustic features and auditory tasks. For the processing of complex sounds, e.g. speech, a number of acoustic features need to be evaluated simultaneously. As a consequence both the left and the right auditory cortex are involved in the processing of such complex sounds and consequently, hemispheric interaction is required. The degree of hemispheric involvement does not solely depend on the acoustic properties of the stimuli but is also influenced by other factors, such as task difficulty, experience from prior training and age. The aim of my project is to systematically determine the effects of these three factors on the lateralization of processing in the human auditory cortices and on the hemispheric interaction by using functional magnetic resonance imaging (fMRI). In particular, the degree of hemispheric involvement will be determined by the contralateral noise procedure that I have developed and validated in the previous funding period. Hemispheric interactions will be studied by connectivity analyses. The results of these analyses will be correlated with diffusion tensor imaging (DTI) measures of the anatomical fine structure of the corpus callosum as the main structure for interhemispheric transfer of information. Based on the results of the previous funding period, two different tasks will be contrasted that require vastly different hemispheric involvement and as a consequence different levels of hemispheric interaction: First, the categorization of tones based on their direction of frequency modulation (FM) will be applied, which relies on a dominant involvement of the right auditory cortex. Second, the sequential comparison of tones based on their FM direction will be applied, which involves both the left and the right auditory cortex to a substantial degree and therefore, requires stronger hemispheric interaction than the categorization task. For the two tasks, the effect of task difficulty on hemispheric involvement and hemispheric interaction will be investigated by comparing three levels of difficulty. Then, the effects of training will be determined by repeated fMRI measurements of the same participants. Finally, the effects of aging in combination with training will be investigated by repeated measurements of older adults. The results of the project will help to answer many of the still open questions regarding hemispheric specialization and its functional consequences. This knowledge is a prerequisite to develop new strategies for maintaining and regaining speech competence of older adults especially in noisy environments as well as of brain damaged patients with deficits in auditory and language processing.

左右听觉皮层分别专门处理基本声学特征和听觉任务。对于复杂声音的处理，例如语音，需要同时评估许多声学特征。因此，左右听觉皮层都参与了这种复杂声音的处理，因此，需要半球相互作用。大脑半球参与的程度不仅取决于刺激的声学特性，还受到其他因素的影响，如任务难度、先前训练的经验和年龄。我的项目目的是通过使用功能性磁共振成像（fMRI）系统地确定这三个因素对人类听觉皮层处理的偏侧化和半球相互作用的影响。特别是，半球的参与程度将由我在之前的资助期间开发和验证的对侧噪声程序决定。半球相互作用将通过连通性分析来研究。这些分析结果将与扩散张量成像（DTI）测量的胼胝体解剖精细结构相关联，胼胝体是半球间信息传递的主要结构。基于前一个资助期的结果，将对比两种不同的任务，这两种任务需要截然不同的半球参与，因此半球相互作用的水平也不同：首先，将应用基于频率调制（FM）方向的音调分类，这依赖于右侧听觉皮层的主导参与。其次，将应用基于调频方向的音调顺序比较，这在很大程度上涉及左右听觉皮层，因此需要比分类任务更强的半球相互作用。对于这两个任务，任务难度将通过比较三个难度水平来研究任务难度对半球介入和半球互动的影响。然后，训练的效果将通过对同一参与者的重复功能磁共振成像测量来确定。最后，将通过对老年人的重复测量来研究衰老与训练相结合的影响。该项目的结果将有助于回答关于半球专业化及其功能后果的许多悬而未决的问题。这一知识是开发新的策略来维持和恢复老年人的语言能力的先决条件，特别是在嘈杂的环境中，以及有听觉和语言处理缺陷的脑损伤患者。