VESTIBULAR INFLUENCES ON SPATIAL ORIENTATION AND VISUOSPATIAL CONSTANCY

描述(申请人提供)：在自拍过程中，图像在视网膜上的运动模式(光流)为观察者的航向提供了有力的线索。然而，光流处理带来了许多计算困难的问题，最显著的例子是物体运动与自运动的分离。关于头部运动的线性分量的前庭信号可以极大地简化从光流中提取与行为相关的信息。利用定量的人类心理物理学，我们验证了前庭信息可以被大脑用来解决流解析问题，区分物体运动和自我运动的假设。此外，我们探讨视觉和前庭信号是否保持内部校准，例如确保不同传感器对相同刺激的估计彼此一致。通过让受试者接触到空间上相互冲突的光流和前庭方向信息，我们测试了两种内部一致性模型：视觉优势模型，它预期前庭感知总是像前庭-眼睛反射一样发生变化，与视觉保持一致；以及基于可靠性的校准模型，它依赖于线索的可靠性，并确保随着时间的推移感官估计的最小方差。根据后者的观点，当视觉可靠性高于前庭可靠性时，前庭知觉应适应于视觉指定的方向，当视觉可靠性低于前庭可靠性时，视觉知觉应适应于前庭指定的方向。我们还将研究外部反馈的影响，以及受试者如何权衡内部一致性与外部准确性。所有实验将使用六自由度运动平台，附加大视场立体投影系统和两个可选的强迫选择方法。这些发现对于使用定量方法理解基本的知觉、视觉/前庭相互作用以及在基础和临床空间定向心理物理学领域开辟新的方向具有重要意义。 公共卫生相关性：了解多感官整合和自我运动感知将促进治疗空间定向障碍的新策略，这些缺陷常见于许多大脑功能障碍，包括阿尔茨海默病。这些缺陷之一是从光流判断航向的能力受损，这种障碍与患者在周围环境中导航的困难有关。这些功能的更好本地化将有助于瞄准新的阿尔茨海默氏症疗法。此外，耳石疾病的神经学相关性仍然是一个谜，在确定有效的治疗策略方面构成了一个主要障碍。了解耳石介导的自我运动知觉的特性对于理解和治疗基本的姿势和空间定向缺陷非常重要。我们的实验旨在填补一个非常显著的知识空白，这对理解并最终治疗空间知觉的基本和认知缺陷很重要。

DESCRIPTION (provided by applicant): The pattern of image motion across the retina (optic flow) during self-motion provides a powerful cue to the heading direction of the observer. However, optic flow processing poses a number of computationally difficult problems, the most notable example being segregation of object motion from self-motion. Vestibular signals about the linear components of head movement can greatly simplify the extraction of behaviorally relevant information from optic flow. Using quantitative human psychophysics, here we test the hypothesis that vestibular information can be used by the brain to solve the flow parsing problem and distinguish object motion and self-motion. In addition, we explore whether visual and vestibular signals maintain internal calibration such as to ensure that estimates of the same stimulus by different sensors agree with one another. By exposing subjects to spatially conflicting optic flow and vestibular heading information, we test two models of internal consistency: a visual dominance model, which expects that, like the vestibulo-ocular reflex, vestibular perception always changes to become consistent with vision, and a reliability-based calibration model, which depends on cue reliability and assures minimum variance sensory estimates over time. According to the latter, vestibular perception should adapt towards the visually-specified heading when visual reliability is higher than the vestibular reliability and visual perception should adapt towards the vestibular-specified heading when visual reliability is lower than the vestibular reliability. We will also examine the effects of external feedback and how subjects weigh internal consistency versus external accuracy. A 6-degree-of-freedom motion platform with attached large field-of-view stereo projection system and two-alternative-forced-choice methodology will be used for all experiments. Findings are important for understanding basic perceptual visual/vestibular interactions using quantitative methodology and opening new directions in the fields of basic and clinical spatial orientation psychophysics. PUBLIC HEALTH RELEVANCE: Understanding multisensory integration and self-motion perception would promote new strategies for treating spatial disorientation deficits common to many brain dysfunctions, including Alzheimer's disease. One of these deficits is an impaired ability to judge heading from optic flow, and this impairment is correlated with patients' difficulty in navigating through their surroundings. Better localization of these functions would help targeting new Alzheimer's therapies. In addition, neurological correlates of otolith disorders are still a mystery, posing a major hurdle in defining effective therapeutic strategies. Understanding the properties of otolith-mediated self- motion perception are important for understanding and treating basic postural and spatial orientation deficits. Our experiments aim at filling a very notable gap in knowledge, important for understanding and ultimately treating basic and cognitive deficits of spatial perception.