Online measure of selective attention and neural function in real-world-listening

描述（由申请人提供）：现实世界的听力情况是复杂和动态的，经常要求我们忽略不相关的听觉信息。理解听觉系统是如何应对这一挑战的，受到当前基于实验室的记录技术的限制。本研究旨在通过使用一种新的方法，同时测量选择性注意任务期间的听觉皮层和脑干诱发反应，来克服这些限制，并开发出更好的真实听力条件下的沟通能力指标。它遵循了使用较少的刺激呈现和自然刺激（即句子）来唤起听觉脑干反应的趋势。在一项涉及选择性地关注两种相互竞争的声音的任务中，将记录在线测量结果，模拟在嘈杂条件下感知语音的常见日常体验。虽然许多听觉功能正常的人可以很容易地完成这项任务，但区分两种相互竞争的听觉流的能力是许多临床人群和老年人每天面临的挑战。因此，为了找出潜在的修复生物标志物，我们试图了解听觉功能的哪些方面对经验敏感，以及这种依赖于经验的可塑性是否会在需要将目标信号与噪声（即竞争的、不相关的信号）分离的听力情况下影响听觉感知。经验依赖的可塑性将通过测试双语者和单语者来评估。双语者被认为具有优越的选择性注意技能。这项研究的动机是最近的证据：(a)有听的语音的声学特征在皮层反应中表现出来，而不相关的流被抑制（当响应通过皮层表面的多电极阵列测量时）和(b)听觉脑干和皮层对刺激的声学特征和声音体验都很敏感10-14，即使在被动聆听条件下8,9,15。根据这一证据，我们假设脑干动态地参与了现实世界的倾听情况，并且由于选择性注意而导致的听觉脑干反应的变化将与注意引起的皮层处理变化形成模式。此外，我们预测在现实世界的交流中，经验会影响选择性注意和感觉加工。为了验证这一点，我们将使用头皮电极，同时记录参与者积极关注两个相互竞争的谈话者之一时的听觉脑干反应和皮层反应。我们预测，选择性注意将增强脑干和皮层对注意说话者的反应，抑制脑干和皮层对忽视说话者的反应。我们预测，听觉体验会改变选择性注意对听觉加工的影响，双语者的听觉多样性越大，选择性注意对听觉加工的影响就越大6,8,9。这项研究将提高我们对在更现实的听力条件下参与的生物机制的认识，而不是在实验室中通常采用的方法，并将确定听觉处理的各个方面，这些方面可能受益于补救。

DESCRIPTION (provided by applicant): Real-world listening situations are complex and dynamic, often requiring us to tune out irrelevant auditory information. Understanding how the auditory system tackles this challenge is stifled by the constraints of current laboratory-based recording techniques. This study aims to overcome these constraints and develop better metrics of communication abilities under real-world listening conditions by using a new methodology that simultaneously measures auditory cortical and brainstem evoked responses during a selective attention task. It follows a growing trend of using a fewer stimulus presentations and natural stimuli (i.e., sentences) to evoke auditory brainstem responses. Online measures will be recorded during a task involving selective attention to two competing voices, mimicking the common daily experience of perceiving speech in noisy conditions. While many with normal auditory function can do this task with ease1, the ability to segregate two competing auditory streams is a daily challenge faced by many clinical populations2,3 and older adults4,5. Therefore, in an effort to pinpoint potential biomarkers of remediation, we seek to understand which aspects of auditory function are sensitive to experience and if this experience-dependent plasticity influences auditory perception during listening situations that require separating a target signal from noise (i.e., competing, irrelevant signals). Experience-dependent plasticity wil be assessed by testing bilinguals, a population known to have superior selective attention skills6-9, and monolinguals. This study is motivated by recent evidence that (a) the acoustic features of an attended speech sound are represented in the cortical response while the irrelevant stream is suppressed (when responses are measured by a multi-electrode array on the surface of the cortex) and (b) the auditory brainstem and cortex are sensitive to both the acoustic features of a stimulus and experience with that sound10-14 even under passive listening conditions8,9,15. From this evidence we hypothesize that the brainstem is dynamically involved in real-world listening situations and that the changes in the auditory brainstem response as a result of selective attention will pattern with attention-induced changes in cortical processing. Additionally, we predict that experience influences both selective attention and sensory processing during real- world communication. To test this, we will simultaneously record, using scalp electrodes, auditory brainstem responses and cortical responses as participants are actively attending to one of two competing talkers. We predict that selective attention will enhance both the brainstem and cortical responses to an attended talker and suppress the brainstem and cortical responses to an ignored talker. We predict that auditory experience will change the effect of selective attention on auditory processing, with greater auditory diversity through bilingualism leading to a greater effect of selective attention on auditory processing6,8,9. This study will improve our knowledge of the biological mechanisms engaged during more realistic listening conditions than typically employed in the laboratory and will identify aspects of auditory processing that may benefit from remediation.