Modeling causal inference in vestibular-visual heading perception

描述（由申请人提供）：通过前庭信号和穿过视网膜的图像运动模式（光流）来指示航向。当前庭线索和光流被整合时，航向精度提高。只有当这两种线索是由同一个原因产生的，也就是说，观察者在一个固定的世界环境中的运动，这种多感觉整合才是有益的。然而，光流具有固有的模糊性，这对航向感知提出了关键挑战：光流表示观察者的组合运动以及世界上物体的运动。使用定量的人类心理物理学和数学建模，在这里，我测试的假设，大脑实现了一个决策过程，推断与前庭和视流线索的原因。根据这个被称为“因果推理”的决策过程，如果推断出这两个线索是由共同的原因产生的，那么这两个线索就被整合在一起。因此，因果推理预测，多感官的航向知觉将取决于视觉和光流航向信息之间的冲突的大小，以及这些线索的可靠性。此外，我将调查的influenceof运动物体的航向知觉的因果推理框架内，预测的影响，运动物体的航向知觉将减少的速度在世界上的物体运动的增加。所有实验将使用带有大视场立体投影系统的6自由度运动平台和两种选择强制选择方法。我将开发因果推理过程的数学模型，并使用贝叶斯模型比较技术将这些模型的预测与实验数据进行严格比较。这项研究的结果是重要的理解基本的知觉前庭视觉的相互作用，并在基础和临床空间取向心理物理学领域开辟新的方向。

DESCRIPTION (provided by applicant): Heading direction is indicated by vestibular signals and patterns of image motion across the retina (optic flow). Heading precision improves when vestibular cues and optic flow are integrated. Such multisensory integration will be beneficial only if the two cues are produced by the same cause, that is, movement of the observer in a world-fixed environment. However, optic flow possesses an inherent ambiguity which poses a crucial challenge to heading perception: optic flow indicates the combined movement of the observer as well as movement of objects in the world. Using quantitative human psychophysics and mathematical modeling, here I test the hypothesis that the brain implements a decision process that infers the causes associated with vestibular and optic flow cues. According to this decision process, termed "causal inference", the two cues are integrated if it is inferred that a common cause produced them. Causal inference thus predicts that the multisensory heading percept will depend on the magnitude of the conflict between visual and optic flow heading information as well as the reliability of these cues. In addition, I will investigate the influenceof moving objects on heading perception within the causal inference framework, which predicts that the influence of moving objects on heading perception will decrease as the velocity of object motion in the world increases. A 6 degrees-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. I will develop mathematical models of the causal inference process and will rigorously compare the predictions of these models with the experimental data using Bayesian model comparison techniques. Findings of this research are important for understanding basic perceptual vestibular-visual interactions and opening new directions in the fields of basic and clinical spatial orientation psychophysics.