The Effect of Circular Vection on the Subjective Postural Horizontal in the Pitch Plane

Postural orientation assessments, including the subjective postural horizontal (SPH) test, has been demonstrated as a great tool for assessing otoliths contributions to postural orientation and balance (Beule et al., 2006). Previous work has shown that dynamic visual stimuli, in the form of circular vection (CV) in the roll plane, significantly affects the body position and horizontal orientation perception of the support surface (Cleworth et al., 2023). However, CV in the pitch plane has been shown to introduce a different form of the visual stimulus and elicit distinct postural strategies compared to the roll plane. Therefore, by altering the support surface and visual information, this study aims to examine the effect of applying pitch CV in VR, on the body response and perception of horizontal orientation of the support surface. Overall, pitch CV significantly affected SPH of the platform and body position. This thesis contributes to our understanding of the complex integration of the visual and vestibular systems during postural orientation tests and offers a potential avenue for testing postural orientation and balance deficits in clinical populations.