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具有听觉学习问题的儿童难以学习的机制。先前的研究已经确定，这些孩子在歧视语音的声音中仅在其强型转变中有所不同，这可能是由于处理快速声音的一般听觉缺陷所致。这种缺陷与快速声音的左皮层优势较弱有关。拟议的研究将使用功能性磁共振成像来证明正常儿童（NL）和具有听觉学习障碍儿童（LP）的时间和光谱处理的横向模式。两个系列刺激将源自标准刺激，该标准刺激由两个纯音调组成，这些纯音是由八度分离并以缓慢速度交替交替的。一个系列将系统地提高频率调制速率，同时保持光谱复杂性恒定，而另一个将增加光谱复杂性，同时保持恒定速率。预计NL儿童在左听性皮质区域中显示出更多的活性，而LP儿童的横向偏侧化较弱。预计频谱复杂性的增加将在两组中引起右边的反应。将研究Heschl Gyri（HG）的白质结构方面的差异。白质体积和各向异性（微观完整性的量度）将以所有儿童的左右HG进行测量，并与单个侧向指数有关。在正常大脑的左hg中发现了比右HG的较大的白质体积，这可能是由于轴突较厚，轴突较厚，这些轴突更快地传递了信息，这是快速信号处理的必要组成部分。左HG中较小的白质体积或异常各向异性可能是LP儿童快速听觉加工的潜在缺陷。拟议的研究的一个重要方面是，来自已经从所有受试者中收集的与语音感知有关的各种知觉，教育和电生理学指标的数据可用。这将允许对这些度量与功能性横向指数之间的关系进行系统的评估。可以预期，在各个儿童中，这些方法中的数据集成在不同研究中比较不同的受试者群体时很难发现的关系。