The Delay in Visual Reorientation following Exposure to a Change in Direction of Resultant Force on a Human Centrifuge

Three subjects were exposed on a human centrifuge to a change in direction of resultant G relative to the body axis. Under the conditions of the experiment the illusion was created wherein a horizontal target line appeared to rotate through an angle corresponding to the change in direction of the resultant force. The subject's task was to keep the line horizontal at all times. Thus, if the line appeared to rotate clockwise, the subject actually rotated the line counterclockwise in order to maintain the line horizontal for himself. A marked discrepancy was noted between the time required to impress the physical force on the subject and the period during which he found it necessary to make adjustments in keeping the line horizontal. This discrepancy was regarded as a measure of the delay in the subject's visual reorientation to a change in direction of resultant G. It is thought that a possible cause of the delay may lie in the characteristic behavior of the otolith organ. This lag phenomenon is of importance to aviation inasmuch as the full disorientating effects of a change in direction of resultant G relative to the body axis will not become manifest if the exposure time is short. (Author)

Acoustics · Centrifuge · Clockwise · Cognitive psychology · Geodesy · Geometry · Horizontal plane · Illusion · Line (geometry · Mechanics · Movement (music · Optics · Physics · Visual angle · Ergonomics and Musculoskeletal Disorders · Geology · Mathematics · Psychology · Spatial Cognition and Navigation · Visual perception and processing mechanisms