Visual determinants of postural control and perception during physical and visual motion

Abstract

The control of balance and posture is a critical task of daily life to limit the risk of falls and potential injury. In order to be successful in the control of balance the central nervous system utilizes sensory feedback from the visual, proprioceptive/somtatosensory and vestibular systems. It is through the detection, processing and perception of these sensory cues that allow us to form an accurate representation of postural events and respond accordingly. In this dissertation I investigate how we perceive postural events, how this perception can change with altered visual cues introduced through virtual reality and how virtual visual motion with differing context can alter postural responses. This dissertation aims to determine the following: (1) to determine if methodological changes effect an individuals perception of postural instability onset, (2) to investigate if visual information can alter our perception of instability onset, (3) to investigate if visual motion with differing visual characteristics can alter postural responses. Results indicate that the methodology utilized during a temporal order judgement task has an effect on the perception of postural instability onset. Additionally, it was observed that virtual visual height impacts the precision of perceptual responses to postural instability onset. Finally, virtual visual motion with differing visual context appeared to only be affected by visual motion duration. However, there were also strong individual differences in postural responses to visual motion, which has not been broadly addressed in the literature. As a whole this thesis can exemplify the importance of visual information on both perceptual and behavioural responses related to posture and balance.