Individual differences in brain networks supporting speech understanding in patients with cochlear implants

摘要 听力障碍的听众通常能听懂口语，但随着努力的增加， 远离注意力和记忆等其他过程的认知资源。一个重要的挑战是 因此，要了解大脑如何应对退化的语音信号以及认知过程 对成功理解来说是最关键的。植入人工耳蜗的成年听者是一个独特的群体 用什么来研究努力倾听：他们通常已经适应了一段时间的听觉剥夺 严重的听力损失，然后在植入后一定程度的听力恢复。跟随 由于植入人工耳蜗而增加的听觉输入，即个体听者能够 成功识别语音，特别是在存在背景噪声的情况下，是非常不稳定的。上一首 试图在大脑活动的潜在模式的背景下解释这种可变性的尝试没有成功， 在很大程度上是因为与植入的神经成像相关的技术挑战 医疗设备阻止了对语音的神经反应的充分定位。我们研究的目标是 是了解支持植入人工耳蜗的听者的语音识别的认知系统 利用关于这些系统的知识来改善行为结果。我们使用融合的证据来这样做 来自行为测量和脑功能成像。我们利用高密度漫反射光学 断层扫描(HD-DOT)，一种光学脑成像形式，产生局部解剖定位的指数 大脑皮层活动。我们将绘制大脑网络图，支持有耳蜗的听者的言语理解 植入物，我们预计这与听力良好的听众使用的植入物不同。然后我们将评估 用心听的神经标记能在多大程度上预测语音识别中的个体差异 在存在背景噪音的情况下取得成功。总之，这些发现将有助于我们对 在神经解剖学受限的框架中植入人工耳蜗辅助语音识别并开发更多 准确的结果衡量标准。

Abstract Listeners with hearing impairment can often understand spoken language, but with increased effort, taking cognitive resources away from other processes such as attention and memory. An important challenge is therefore to understand how the brain copes with a degraded speech signal and the cognitive processes that are most critical to successful comprehension. Adult listeners with cochlear implants are a unique group in which to investigate effortful listening: They have typically adapted to auditory deprivation for a period of years of profound hearing loss, followed by some degree of hearing restoration following implantation. Following increased auditory input due to cochlear implantation, the degree to which individual listeners are able to successfully recognize speech, especially in the presence of background noise, is extremely variable. Previous attempts to explain this variability in the context of underlying patterns of brain activity have been unsuccessful, in large part because the technical challenges associated with neuroimaging in the presence of an implanted medical device have prevented adequate localization of neural responses to speech. The goal of our research is to understand the cognitive systems that support speech recognition in listeners with cochlear implants and to use knowledge about these systems to improve behavioral outcomes. We do so using converging evidence from behavioral measures and functional brain imaging. We make use of high-density diffuse optical tomography (HD-DOT), a form of optical brain imaging that produces anatomically-localized indices of regional cortical activity. We will map the brain networks supporting speech comprehension in listeners with cochlear implants, which we expect to differ from those engaged by listeners with good hearing. We will then evaluate the degree to which neural markers of effortful listening can predict individual differences in speech recognition success in the presence of background noise. Together the findings will help ground our understanding of cochlear implant-aided speech recognition in a neuroanatomically-constrained framework and develop more accurate outcome measures.