Colloquium Series 2015-2016

Michael Barnett-Cowan
University of Waterloo

Gravity's Fundamental Role for Perception and Action

Orientation is fundamental to perception and action. Knowing where you are in relation to the world and its contents is critical for adaptive behaviour. Orientation requires a reference, which the force of gravity is ideally suited for because it is constant on earth. The senses provide different types of information about the direction of gravity however. Thus a critical step that the brain must achieve to accurately represent the world and its contents is the integration of orientation cues from multiple sensory organs that individually do not provide an accurate representation of the physical world. Under normal circumstances when the head is upright with respect to the direction of gravity’s force and with respect to the orientation of a polarized visual environment, perceived self-orientation within an earth-centric field of reference is reinforced by such sensory cues. Perceptual stability is compromised, however, when orientation information from the senses is discordant. In this talk I will present a number of behavioural studies that demonstrate how fundamental gravity is to perception and action at the individual and group level. I will then briefly introduce a new research project designed to address these individual and group differences using genomics and will conclude by opening a discussion on how developing a working computational model of how the brain integrates multisensory information about orientation could be used to better predict, monitor and treat disorientation as well as sensory processing deficits that come with ageing and disease.