NEUROIMAGING, AUDIOLOGY, PSYCHOACOUSTICS

该项目的第一项任务是招募人类受试者， 方案项目。二是从听觉上表征 正常人的年轻和老年受试者的代表性样本 听力和听力损失的人将进行比较实验， 心理声学、诱发电位、反射行为和正电子发射 断层扫描第三个目的是评估与年龄有关的变化， 时间处理的心理物理学，噪声中信号的处理， 和人类的双耳处理。最初的差距检测研究 在老年人中， 具有基本正常的外周敏感性的成年人。此外，我们还展示了 处理速度会不成比例地降低， 刺激配置增加。这表明，与年龄有关的 变化发生在整个中枢听觉神经系统的多个部位， 系统和额外，不成比例的大幅度减少， 需要双耳处理来揭示处理。我们 第四个目标是利用正电子发射断层扫描（PET））， 研究发生在中枢听觉的功能变化， 系统由于老化和老年性耳聋。我们提出了一个详细的系列 将老化的影响与高频率 感音神经性听力损失（SNHL）。此外，我们计划调查 异常快速响度增长的功能神经解剖学 （“招募”）和异常声音定位，这两个障碍， 与年龄和SNHL相关。我们将通过确定 外音强度与外音程度之间的关系 听觉皮层的激活以及这种关系如何受到 与年龄相关的SNHL。我们会继续调查- 频率SNHL影响老年人的皮层频率-位置图。 我们将进行实验，以确定双耳声音提示 参与声音定位的信号由大脑皮层处理， 确定老化和高频SNHL对双耳 处理.

The first task of this project is to recruit human subjects required for the Program Project. The second is to audiologically characterize representative samples of human of young and old subjects with normal hearing and hearing losses who will undergo comparative experiments in psychoacoustics, evoked potentials, reflex behavior, and positron emission tomography. The third aim is to evaluate age-related changes in the psychophysics of temporal processing, the processing of signal in noise, and binaural processing in humans. Initial gap detection studies have demonstrated age-related slowing in auditory temporal processing in older adults with essentially normal peripheral sensitivity. Also, we have shown that processing speed decreases disproportionately as the complexity of the stimulus configuration increases. This suggests that age-related changes occur at multiple sites throughout the central auditory nervous system and that additional, disproportionately large, decrements in processing will be revealed with binaural processing is required. Our fourth aim is to utilize Positron Emission Tomography (PET)) to investigate the functional changes that occur in the central auditory system as a result of aging and presbycusis. We propose a detailed series of experiments to separate the effects of aging from high-frequency sensorineural hearing loss (SNHL). In addition, we plan to investigate the functional neuroanatomy of abnormally rapid loudness growth ("recruitment") and abnormal sound localization, two impairments which are associated with age and SNHL. We will do so by determining the relationship between the intensity of an external tone and the degree of activation in the auditory cortex and how this relationship is affected by aging and by age-related SNHL. We will pursue the question of how high- frequency SNHL affects the cortical frequency-place map in old subjects. And we will conduct experiments to determine how binaural sound cues involved in sound localization are processed by the cerebral cortex and to determine the effect aging and high-frequency SNHL have on binaural processing.