Multisensory processing during self-motion

自我运动过程中的多感官处理

• 批准号: RGPIN-2014-05435
• 负责人: BarnettCowan, Michael
• 金额: $ 2.55万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=685665
• 关键词: Multisensory; processing; during; self; motion

Think about a time you or a friend felt motion sick. Perhaps you were in the backseat of a car on a twisty road. Maybe, you were on an amusement ride, where you and your friend were on a spaceship zipping around a virtual world. Why is it that only one of you got sick? Now imagine a time you fell down. Perhaps you tripped, fell down the stairs, or slid on some ice. Do you have a good sense of recalling the full sequence of events from the onset of the fall? Perhaps you remember just one moment such as the blueness of the sky or reaching out to a rail on your way down. We know relatively little about how sensory information is processed during self-motion (even less during a fall) and what can predict the incidence of motion sickness across individuals. My past research has shown that the brain dissociates how it processes vestibular signals (information about head movement) for generating reflexive responses and for making perceptual responses, and that individuals vary when judging the perceived relative timing of sensory events. The goal of this proposal is to develop a comprehensive model of how the timing of multisensory events affects perceptual, physiological, and neural responses to self-motion. I will develop three themes: (1) PERCEIVED TIMING OF MULTISENSORY EVENTS DURING SELF-MOTION. My recent work has found that vestibular information must be presented prior to other sensory events in order to be perceived as simultaneous. This suggests, surprisingly, that vestibular perception is slow while vestibular reflexes are fast. I expect to find similar results when people fall. Much needed parametric assessment of perceived vestibular delay paired with physiological and neural responses to self-motion will be used to construct a theoretical model of the neural mechanisms that subserve delayed vestibular perception. (2) SENSORY CUE INTEGRATION DURING SELF-MOTION. Maximum-likelihood estimation can be used to reliably predict how sensory cues are integrated by the brain. To investigate cue combination for self-motion quantitatively, variances associated with visual and vestibular estimation of self-motion are independently measured, combined by a maximum-likelihood integrator, and compared to perceived self-motion with both cues present. I expect that discrepancies in finding optimal integration of visual and vestibular cues in the literature result from change in visual sensitivity during self-motion and perceived temporal delays between sensory cues. (3) MOTION SICKNESS COUNTERMEASURES DURING SELF-MOTION. Sensory conflict occurs in man-made environments, often leading to motion sickness whose severity and incidence varies widely across individuals. Temporal delay in motion simulators is well known to induce motion sickness and engineers do their best to reduce temporal delay between visual and vestibular cues to zero. I expect that motion sickness can be minimized when this temporal delay is calibrated relative to each individual's point of subjective simultaneity. My research program recognizes the role of the vestibular system as fundamental to cognition. Knowing how vestibular information is temporally processed and how it affects perceived self-motion is critical not only to understand how the brain works but also to reduce the incidence of motion sickness, which is holding back wider adoption of cost-saving virtual reality technology in the aviation, space, design, mobile computing, and healthcare industries. Likewise, a deeper understanding of the dissociation between processing vestibular information for reflexive responses versus conscious awareness could help in the development of preventative interventions to help reduce fall-related injury; a $3 billion burden to the Canadian economy (Public Health Agency of Canada).

想想你或你的朋友感到晕车的时候。也许你坐在汽车的后座上，在一条曲折的路上。也许，你是在一个游乐设施，你和你的朋友在一个虚拟世界的宇宙飞船压缩。为什么只有一个人生病了？现在想象一下你摔倒的时候。也许你绊倒了，从楼梯上摔下来，或者在冰上滑倒。你能很好地回忆起从跌倒开始的整个过程吗？也许你只记得一个时刻，比如天空的蔚蓝，或者在你下山的路上伸手去抓栏杆。我们对自我运动过程中感觉信息的处理方式知之甚少（跌倒时更是如此），也不知道如何预测个体的晕动病发病率。我过去的研究表明，大脑如何处理前庭信号（关于头部运动的信息）以产生反射性反应和做出感知反应，以及个体在判断感觉事件的感知相对时间时存在差异。这个建议的目标是开发一个综合模型，多感官事件的时间如何影响感知，生理和神经反应的自我运动。我将展开三个主题：（1）自我运动过程中多感觉事件的感知时间。我最近的研究发现，前庭信息必须先于其他感觉事件呈现，才能被感知为同时发生的。令人惊讶的是，这表明前庭感知是缓慢的，而前庭反射是快速的。我希望当人们摔倒时也能找到类似的结果。非常需要的参数评估与生理和神经反应的自我运动的前庭延迟配对将被用来构建一个理论模型的神经机制，有助于延迟前庭知觉。(2)自我运动过程中的感觉线索整合。最大似然估计可以用来可靠地预测大脑如何整合感官线索。要调查线索组合的自我运动定量，方差与视觉和前庭估计的自我运动独立测量，结合最大似然积分，并与感知的自我运动与两个线索存在。我预计，在寻找最佳整合的视觉和前庭线索的文献中的差异，导致在自我运动和感知之间的感官线索的时间延迟的视觉灵敏度的变化。(3)自我运动期间的运动病对策。感觉冲突发生在人造环境中，通常会导致晕动病，其严重程度和发病率在个体之间差异很大。众所周知，运动模拟器中的时间延迟会引起运动病，工程师们尽最大努力将视觉和前庭提示之间的时间延迟减少到零。我希望，当这个时间延迟相对于每个人的主观意识点进行校准时，运动病可以最小化。我的研究计划认识到前庭系统作为认知基础的作用。了解前庭信息是如何在时间上处理的，以及它如何影响感知到的自我运动，不仅对了解大脑如何工作至关重要，而且对减少晕动病的发生率也至关重要，晕动病阻碍了航空、航天、设计、移动的计算和医疗保健行业更广泛地采用节省成本的虚拟现实技术。同样，更深入地了解前庭信息处理反射性反应与有意识之间的分离，可以帮助开发预防性干预措施，以帮助减少跌倒相关的伤害;加拿大经济的30亿美元负担（加拿大公共卫生署）。