Neuronal Correlates of the Visual Modulation of Auditory Performance

描述（由申请人提供）：在自然环境中，大脑经常面临着解释在存在噪音的情况下发生的听觉信号的艰巨任务，这可能使重要的听觉事件变得模糊和不那么突出。然而，在自然环境中，这些听觉线索通常伴随着视觉信息，通常来自相同的事件。这种同时存在的视听线索可以极大地放大感兴趣刺激的显著性。然而，尽管许多研究已经说明了拥有多感官（如视听）线索的行为和感知益处，并且越来越多的文献描述了表征多感官相互作用的神经编码过程，但很少有研究能够将多感官神经变化与其行为和感知相关联系起来。为了更牢固地建立这些联系，我们将训练恒河猴检测或定位目标声音（信号），并忽略正在进行或同时发生的非目标声音（噪音）。信号和噪声之间的空间和时间关系是不同的，以评估它们对猴子检测或定位信号的程度的影响。类似的实验将在添加视觉刺激的情况下进行，其位置和/或时间将变化，以便有时与信号相匹配，有时与噪声相匹配。这将使我们能够评估非听觉（视觉）刺激对听觉行为表现的影响，并使我们能够评估多感觉整合的大脑机制。下丘和上丘神经元的神经生理学记录有望揭示它们在听觉和视听检测和定位行为中的不同作用。这项工作的翻译和临床相关性对于听力受损和老年人来说非常高，因为听觉辅助设备通常在嘈杂的环境中表现不佳。更多地了解大脑如何在噪音中处理听觉信号，以及视觉信息如何在复杂环境中增强神经和行为表现，将对设计更好的技术来处理听力损失及其对生活质量的深刻影响有很大的帮助。

DESCRIPTION (provided by applicant): In the natural environment, the brain is often confronted with the daunting task of interpreting auditory signals that occur in the presence of noise, which can render important auditory events ambiguous and less salient. However, in naturalistic circumstances these auditory cues are typically accompanied by visual information, often from the same events. The presence of such coincident audiovisual cues can greatly amplify the salience of a stimulus of interest. However, although a number of studies have illustrated the behavioral and perceptual benefits of having multisensory (e.g., audiovisual) cues available, and a growing literature on the neural encoding processes that characterize multisensory interactions, very few studies have been able to link multisensory neural changes to their behavioral and perceptual correlates. To more firmly establish these links, we will train rhesus monkeys to detect or localize a target sound (signal), and ignore ongoing or simultaneously occurring non-target sounds (noise). The spatial and temporal relationships between the signal and noise will be varied, to evaluate their effects on how well the monkey detects or localizes the signal. Similar experiments will be performed with the addition of visual stimuli, whose location and/or timing will be varied such that it sometimes matches that of the signal, and sometimes that of the noise. This will allow us to assess the effects of non-auditory (visual) stimuli on auditory behavioral performance and allow us to evaluate brain mechanisms of multisensory integration. Neurophysiological recordings of neurons in the inferior and superior colliculi are expected to reveal their differential role in auditory and audiovisual detection and localization behaviors. The translational and clinical relevance of this work is very high for the hearing impaired and the elderly, in that auditory assistive devices often perform poorly in noisy environments. Greater knowledge of how the brain processes auditory signals within noise, and how visual information can enhance neural and behavior performance in complex environments, will be of great utility for the design of better technologies to deal with hearing loss and its profound impact on quality of life.