Relationship between Change in Ocular Counterrolling and Change in Directional Cognition in Long-Term Tilt Loading

Ocular Counterrolling (OCR) was induced using a body tilting apparatus, and change in OCR was recorded with the passage of time. In addition, changes in subjective cognition of direction and body axis associated with change in OCR were also analyzed. Based on the results, the time-course change in OCR was classified into two groups: Group I, showing constant change (response) and Group II, showing gradual reduction. In Group I, subjective cognition of gravitational axis and body axis was relatively accurate, while said cognition was less accurate in Group II. These results suggested that change in OCR is not simply induced by the otolith organ alone but affected by input from the trunk and deep sensation receptors; these factors may be involved in adaptation and habituation. This study also suggested that OCR reflects cognition of the body axis and direction or spatial orientation.