Auditory lateralization in learning-disabled children

学习障碍儿童的听觉偏侧化

• 批准号: 6911630
• 负责人: CATHERINE M WARRIER
• 金额: $ 7.43万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6911630
• 关键词: adolescence (12-20); audiometry; auditory cortex; auditory discrimination; auditory pathways; behavior test; behavioral /social science research tag; cell morphology; cerebral dominance; clinical research; functional magnetic resonance imaging; hearing tests; human subject; learning disorders; middle childhood (6-11); neural information processing; psychophysics; questionnaires; sound perception; speech recognition; statistics /biometry

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the mechanisms by which children with auditory-based learning problems have difficulty learning. Previous research has established that these children have particular difficulty discriminating speech sounds differing only in their formant transitions, likely due to a more general auditory deficit in processing rapid sounds. This deficiency has been related to a weaker left-cortical dominance to rapid sounds. The proposed study will use functional magnetic resonance imaging to demonstrate lateralization patterns of temporal and spectral acoustic processing in normal children (NL) and children with auditory-based learning disabilities (LP). Two series of stimuli will be derived from a standard stimulus consisting of two pure tones separated by an octave and alternating at a slow rate. One series will systematically increase the rate of frequency modulation while keeping spectral complexity constant, and the other will increase spectral complexity while keeping a constant rate. NL children are predicted to show more activity in left auditory cortical regions with increasing rate of frequency modulation, while LP children show weaker lateralization. Increased spectral complexity is expected to elicit right-lateralized responses in both groups. Differences in structural aspects of the white matter of Heschl's Gyri (HG) will be investigated. White matter volumes and anisotropy (a measure of microstructural integrity) will be measured in right and left HG of all children and related to individual laterality indices. Larger white matter volumes have been found in left than right HG in normal brains, likely due to thicker myelination of axons which allow faster transfer of information, a necessary component of rapid signal processing. Smaller white matter volume or abnormal anisotropy in left HG could potentially be underlying deficiencies of fast auditory processing in LP children. An important aspect of the proposed study is the availability of data from a wide variety of perceptual, educational, and electrophysiologic measures related to speech perception that have already been collected from all subjects. This will allow a systematic assessment of relationships between these measures and functional laterality indices. It is expected that the integration of data across these many methodologies within individual children will reveal relationships that have previously been difficult to uncover when comparing across different groups of subjects in different studies.

描述（由申请人提供）：该项目的长期目标是了解有听觉学习问题的儿童学习困难的机制。先前的研究已经证实，这些孩子在区分仅在共振峰转换方面有所不同的语音方面特别困难，这可能是由于在处理快速声音方面存在更普遍的听觉缺陷。这种缺陷与左皮质对快速声音的支配力较弱有关。拟议的研究将使用功能磁共振成像来证明正常儿童（NL）和有听觉学习障碍的儿童（LP）的时间和频谱声学处理的偏侧化模式。两个系列的刺激将从标准刺激中衍生出来，该标准刺激由两个纯音组成，两个纯音之间间隔一个八度并以慢速交替。一个系列将系统地增加频率调制速率，同时保持频谱复杂性恒定，而另一个系列将在保持恒定速率的同时增加频谱复杂性。随着频率调制率的增加，预计 NL 儿童的左听觉皮层区域会表现出更多的活动，而 LP 儿童则表现出较弱的偏侧化。增加的光谱复杂性预计会引起两组的右偏反应。将研究赫施尔回（HG）白质结构方面的差异。将测量所有儿童的左右脑白质体积和各向异性（微观结构完整性的衡量标准），并与个体偏侧性指数相关。在正常大脑中，左脑白质体积比右脑白质体积更大，这可能是由于轴突的髓鞘更厚，从而可以更快地传递信息，这是快速信号处理的必要组成部分。左脑白质体积较小或异常各向异性可能是 LP 儿童快速听觉处理的潜在缺陷。拟议研究的一个重要方面是可以从所有受试者收集到的与言语感知相关的各种感知、教育和电生理测量数据。这将允许对这些措施和功能偏侧指数之间的关系进行系统评估。预计将这些多种方法的数据整合到单个儿童中将揭示以前在不同研究中的不同受试者组之间进行比较时难以发现的关系。