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: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567173
• 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).

想一想您或朋友感到晕车的一次。也许您正坐在汽车的后座上行驶在蜿蜒的道路上。也许，您正在乘坐游乐设施，您和您的朋友乘坐一艘宇宙飞船在虚拟世界中飞驰。为什么你们只有一个人生病了？现在想象一下你跌倒的时候。也许你绊倒了，从楼梯上摔了下来，或者在冰上滑倒了。您是否清楚地回忆起秋天开始以来发生的全部事件？也许您只记得某个时刻，例如蔚蓝的天空或下落时伸手抓住栏杆。我们对自我运动期间如何处理感觉信息（甚至跌倒期间更少）以及如何预测个体晕动病的发生率知之甚少。我过去的研究表明，大脑如何处理前庭信号（有关头部运动的信息）以产生反射性反应和做出知觉反应，并且个体在判断感觉事件的感知相对时间时会有所不同。该提案的目标是开发一个综合模型，研究多感官事件的时间安排如何影响对自我运动的感知、生理和神经反应。我将发展三个主题：（1）自我运动期间多感觉事件的感知时间。我最近的工作发现，前庭信息必须先于其他感官事件呈现，才能被感知为同时发生。令人惊讶的是，这表明前庭感知很慢，而前庭反射却很快。我预计当人们跌倒时会发现类似的结果。急需的感知前庭延迟的参数评估与对自我运动的生理和神经反应相结合，将用于构建促进前庭感知延迟的神经机制的理论模型。 (2) 自我运动期间的感官提示整合。最大似然估计可用于可靠地预测大脑如何整合感觉线索。为了定量研究自我运动的提示组合，独立测量与自我运动的视觉和前庭估计相关的方差，通过最大似然积分器组合，并与存在两种提示的感知自我运动进行比较。我预计文献中寻找视觉和前庭线索最佳整合的差异是由于自我运动过程中视觉敏感性的变化以及感觉线索之间感知的时间延迟造成的。 (3) 自行运动时的晕车对策。感官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因人而异。众所周知，运动模拟器中的时间延迟会引起晕动病，工程师尽最大努力将视觉和前庭提示之间的时间延迟减少到零。我希望当这种时间延迟相对于每个人的主观同时性点进行校准时，晕动病可以最小化。我的研究项目认识到前庭系统的作用是认知的基础。了解前庭信息如何在时间上进行处理以及它如何影响感知的自我运动不仅对于了解大脑如何工作至关重要，而且对于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，更深入地了解处理反射反应的前庭信息与意识意识之间的分离可能有助于制定预防性干预措施，以帮助减少跌倒相关的伤害；给加拿大经济带来 30 亿美元的负担（加拿大公共卫生局）。