Visual Speech Perception and Neural Processing

描述(由申请人提供)：对可视语音的感知(唇读/朗读)足以习得一门第一语言并进行日常交流。在嘈杂的条件下，听力损失的人可能需要依赖唇读，即使他们有感官辅助设备(助听器、人工耳蜗)。唇读在有语前严重听力障碍(聋人)的人中表现出可塑性，以至于聋人的准确率经常远远超过听力正常的成年人的准确率。这项拟议项目的长期研究目标是从感觉和知觉过程以及潜在的神经机制方面解释唇读在聋人专家、听力正常的个人和特发性突发性重度听力损失的个人中的作用。长期的临床目标是开发有效的唇读训练和评估工具。在研究1中，假设专业的聋人成人读唇者在与视觉空间频率加工有关的低感觉限制水平上比听力正常的成年人更有能力。这项研究应用了一种使用对比度阈值估计视觉临界空间频带的方法。在研究2中，假设对视觉语音刺激的更快和更灵敏的知觉加工是专家翻译器优势的主要组成部分。采用快速辨别方法研究视觉语音的知觉敏感性和长时记忆结构。在研究3中，同样的假设将被检验，但刺激将由一种新的视觉语音合成器产生。在研究4中，假设专家唇读与语音外源性和可能的神经可塑性皮质效应有关。电生理事件相关电位(ERPs)将在目标辨别任务中获得。语言前期失聪的成年人是唇读专家，他们将与听力正常的成年人进行比较，以找出专家唇读优势的来源。突发性听力损失的患者将被招募来研究在输入刺激突然改变后可能迅速发生的知觉和神经整形效应。与公众健康的相关性：实验旨在导致更有效的唇读评估和培训，这将与各种情况相关，包括听力损失和在噪音条件下的感知能力下降。视觉语音合成器的应用包括基于计算机的听力障碍儿童的语音感知训练系统。成年人的学习和可塑性知识很重要，因为听力损失是与衰老有关的常见情况。

DESCRIPTION (provided by applicant): Perception of visible speech (lipreading/speechreading) can be sufficient for acquiring a first language and carrying out everyday communication. Under noisy conditions, individuals with hearing loss may need to rely on lipreading, even if they have sensory aids (hearing aids, cochlear implants). Lipreading demonstrates plasticity in individuals with prelingual profound hearing impairments (deaf), such that accuracy in deaf adults frequently far exceeds accuracy in normal-hearing adults. The long-term research aim of this proposed project is to explain, in terms of sensory and perceptual processes and underlying neural mechanisms, lipreading in deaf experts, in individuals with normal hearing, and in individuals with idiopathic sudden profound hearing loss. The long-term clinical aim is to develop effective tools for lipreading training and assessment. In Study 1, it is hypothesized that expert deaf adult lipreaders are more capable at the level of lower-sensory constraints related to visual spatial frequency processing than are normal-hearing adults. The study applies a method for estimating visual critical spatial frequency bands using contrast thresholds. In Study 2, it is hypothesized that faster and more sensitive perceptual processing of the visual phonetic stimulus is a major component of the expert lipreader's advantage. A speeded discrimination method will be used to study perceptual sensitivity and longterm memory structure for visual phonetic speech. In Study 3, the same hypothesis will be tested, but the stimuli will be generated with a new visual speech synthesizer. In Study 4, the hypothesis is that expert lipreading is associated with phonetic exogenous and possibly neuroplastic cortical effects. Electrophysiological event related potentials (ERPs) will be obtained during a target discrimination task. Prelingually deaf adults who are expert lipreaders will be compared with normal- hearing adults to isolate sources of the expert's lipreading advantage. Patients with sudden hearing loss will be recruited to study perceptual and neuroplastic effects that may occur rapidly following an abrupt change in input stimulation. Relevance to public health: Experiments are designed to lead to more effective lipreading assessment and training, which would be relevant to a wide range of conditions involving hearing loss and degraded perception under noisy conditions. Applications of the visual speech synthesizer include computer-based training systems for speech perception in children with hearing impairments. Knowledge about learning and plasticity in adults is important, as hearing loss is a frequent occurrence associated with aging.