Tilted Room 1 On the Relation between Roll and Pitch ( preprint )

Studies have found that rolling the visual environment affects observers’ perception of gravitational vertical and horizontal and that pitching the environment affects observers’ perception of pitch. However, the relationship between these two perceptions is not fully understood. In the present work, observers performed three tasks while in a visual surround whose pitch and roll was manipulated. In the first task, observers adjusted a rod in the frontal-parallel plane to the horizontal (roll). In a second task, they adjusted a rod along a plane parallel to straight-ahead to the vertical (pitch). In the final task (“in-between”), they adjusted a rod midway between the first two conditions. The typical pitch and roll effects were found, as well as a contribution of both pitch and roll to the in-between task. No interaction between pitch and roll effects was found, indicating independent cognitive representations.