Neural Mechanisms of Speech Perception in Noise in Middle-Age

点击翻译按钮获取中文摘要

ABSTRACT Normal aging is associated with difficulty understanding speech in adverse listening conditions. A large literature demonstrates that pure tone hearing thresholds alone do not provide an adequate profile of an individual’s speech perception in noise (SPIN) abilities, and even individuals with normal sensitivity tend to complain of speech perception difficulties. Studies of SPIN in aging often compare older adults against younger adults. In contrast, fewer studies investigate SPIN difficulties in middle-aged adults, leaving a large gap in our knowledge of SPIN mechanisms in aging. In older adults, pervasive changes throughout the nervous system, including subcortical temporal processing, cognitive effort, and compensatory frontal activity are related to reduced SPIN performance. The overall goal of this proposal is to investigate the neural mechanisms of SPIN in younger and middle-aged adults with normal hearing sensitivity using a multimodal neuroimaging and computational cognitive neuroscience approach. To achieve this overall goal, this proposal is composed of two study aims: 1) examine the extent to which temporal processing and cognitive effort during SPIN are affected by middle-age, and 2) quantify compensatory neural recruitment during SPIN. In service of the first aim, we will compare temporal processing abilities and cognitive effort during SPIN in younger and middle-aged adults with and without self- reported SPIN difficulties. In service of the second aim, we will investigate the presence of frontal motor cortex recruitment during SPIN among the same individuals from the first aim using functional magnetic resonance imaging and simultaneous pupillometry to assess cognitive effort. Upon completion of the project outlined in this proposal, we will gain a better understanding of neural mechanisms associated with SPIN in aging, SPIN abilities in middle-age, and mechanisms driving SPIN difficulties in individuals with normal hearing sensitivity. The findings from this study also have the potential to inform whether individuals may be responsive to auditory or cognitive rehabilitation to mitigate SPIN difficulties.