Visual–Vestibular Integration for Self-Motion Perception

Excerpt

How do we perceive our direction of self-motion through space? To navigate effectively through a complex three-dimensional (3-D) environment, we must accurately estimate our own motion relative to objects around us. Self-motion perception is a demanding problem in sensory integration, requiring the neural combination of visual signals (e.g., optic flow), vestibular signals regarding head motion, and perhaps also somatosensory and proprioceptive cues (Hlavacka et al. 1992, 1996; Dichgans and Brandt 1974). Consider a soccer player running downfield to intercept a pass and head the ball toward the goal. This athlete must be able to accurately judge the trajectory of the ball relative to the trajectory of his/her self-motion, in order to precisely time his/her head thrust to meet the ball. Optic flow and vestibular signals are likely the two most sensitive cues for judging self-motion (Gu et al. 2007, 2008; Fetsch et al. 2009). To understand the need for multisensory integration of these cues, it is useful to consider the strengths and weaknesses of each cue. Although self-motion generally involves both translations and rotations of the observer, we shall limit the scope of this review to translational movements, such that we focus on visual and vestibular cues that determine our perceived direction of heading.