Bimodal Updating Hypothesis

双峰更新假设

• 批准号: 9384174
• 负责人: TERRY T TAKAHASHI
• 金额: $ 42.2万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-30 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9384174
• 关键词: Area; Auditory; Barn Owls; Behavioral; Brain; Head; Hearing; Human; Literature; Manuals; Modality; Motor; Nature; Neurons; Pattern; Performance; Process; Psychophysics; Reporting; Research Project Grants; Saccades; Sensory; Sound Localization; Stimulus; Stream; Strigiformes; Tectum Mesencephali; Testing; Time; Tyto alba; Update; Vision; Visual; Visuospatial; auditory stimulus; extracellular; gaze; improved; multimodality; multisensory; neurophysiology; novel; paired stimuli; receptive field; relating to nervous system; response; sound; spatiotemporal; superior colliculus Corpora quadrigemina; visual information; visual stimulus

Project Abstract Objects in nature can be better detected or localized by integrating information across multiple senses. Much of the focus in the literature has been on “facilitation”, the degree to which, for example, an audiovisual (AV) stimulus evokes responses that are faster or more precise than that achieved with the faster or more precise of the two modalities. The project proposed focuses on a different type of facilitation, first reported in humans, in which performance with bimodal stimuli combines the best features of each modality alone. The applicant’s lab demonstrated a similar result in the barn owl (Tyto alba): An owl turns its head toward auditory targets with shorter latencies but lower precision than toward visual targets. Conversely, head-turns to visual targets take longer to initiate, but are more precise. AV-guided head-turns are both fast and precise, but neither faster nor more precise than to audition and vision, respectively. Correspondingly, neuronal latencies in the owl’s optic tectum (OT), an area involved in the direction of gaze, are shorter for auditory stimuli than for visual stimuli. Conversely, visual spatial receptive fields (SRFs) are finer than auditory SRFs. This novel form of multisensory enhancement will be studied neurophysiologically and behaviorally, guided by the hypothesis that auditory information arrives in the OT first, triggering the head turn. The visual information, arriving later, helps to refine the trajectory of the head turn. Each aim is guided by an organizing question: Aim 1. Do owls update only if later arriving information improves localization or does it update to the later arriving information even at the expense of performance? We will blur the visual component of an AV stimulus to determine whether information from the blurred visual component is incorporated or ignored. Aim 2. Auditory and visual input arrives at the OT with different latencies. What is the delay between the auditory and visual streams beyond which updating is no longer observed? We will test two alternative hypotheses: 1.) Updating is limited by a fixed time window that closes during a saccade, or 2.) Updating requires the temporal overlap between the tectal neural responses to auditory and visual stimuli. To distinguish between these ideas, we will vary the duration of sound as we test various time delays between the auditory and visual components of AV stimuli. Aim 3. Is updating exclusive to multimodal stimuli? A sequential pair of unimodal auditory and visual stimuli will be presented in which the localizability of stimuli are altered to determine whether or not information from both senses is necessary.

项目摘要 通过集成信息，可以更好地检测或定位自然界中的对象 多重感官。文献中的大部分焦点都集中在“促进”上，即 例如，视听(AV)刺激唤起更快或更多的反应 精确度比两种模式中速度更快或更精确的模式更精确。该项目 建议的重点是一种不同类型的促进作用，首次在人类中报道，在这种促进作用中 双峰刺激的表现结合了每种模式的最佳特征。这个 申请人的实验室在谷仓猫头鹰(Tyto Alba)身上展示了类似的结果：猫头鹰转过头来 对于潜伏期较短但精度低于视觉目标的听觉目标。 相反，转向视觉目标需要更长的时间才能启动，但更精确。影音制导 转头既快又准确，但既不比试镜快，也不比试镜更准确 愿景分别为。相应地，猫头鹰视顶盖(OT)的神经元潜伏期 与凝视方向有关，听觉刺激比视觉刺激短。 相反，视觉空间感受野(SRF)比听觉SRF更精细。这种新奇的形式 多感官增强的研究将在神经生理学和行为学的指导下进行 一种假说，认为听觉信息首先到达加时区，从而触发转头。这个 较晚到达的视觉信息有助于完善转头的轨迹。每个目标都是 由一个有组织的问题指导：目标1.只有在后来收到的信息有所改进时才更新OWLS 本地化还是更新到较晚到达的信息，甚至以牺牲性能为代价？我们 会模糊视听刺激的视觉成分，以确定来自 合并或忽略模糊的可视组件。目标2.听觉和视觉输入到达 具有不同延迟的OT。听觉和视觉流之间的延迟是多少？ 是否不再观察更新？我们将测试两个替代假设：1)更新受以下因素限制 在扫视过程中关闭的固定时间窗口，或2。)更新需要时间重叠 顶盖神经对听觉和视觉刺激的反应。要区分这两个 想法，我们将改变声音的持续时间，因为我们测试听觉之间的各种时间延迟 和视听刺激的视觉成分。目标3.更新是否仅限于多模式刺激？一个 将呈现单峰听觉和视觉刺激的顺序对，其中 改变刺激的局部性以确定来自两个感官的信息是否 这是必要的。