Biomaterial Database

A coordinate system for visual motion perception. 2001

W G Darling, and M A Pizzimenti

Department of Exercise Science, University of Iowa, Iowa City, IA 52242, USA. warren-darling@uiowa.edu

The purpose of this research was to determine the reference axes used by the visual system to specify direction of motion of objects by the visual system at the perceptual level. Ten young adults aligned motion of a moving luminous dot on a computer display to body-fixed and external vertical and horizontal plane axes while operating in a dark room. Accuracy of aligning dot motion to earth-fixed vertical, a displayed luminous line (external visual axis) of varied orientations, and head and trunk longitudinal axes was tested in one experiment with the display in the vertical frontal plane. In a second experiment, dot motion was aligned to head and trunk anterior/posterior (A-P) axes and to an external visual axis presented on a horizontal computer screen. Head and trunk orientations were varied in the frontal plane (left/right tilt) when testing vertical plane axes and by rotation of the head and/or trunk about a vertical axis when testing horizontal plane axes. Perceptual errors were lowest when aligning to earth-fixed vertical in the vertical plane and to an external oblique line in the horizontal plane when head and trunk orientations were varied. Perceptions of horizontal plane motion direction were accurate relative to the trunk-fixed A-P axis when only head orientation was varied, but large errors were made when trunk orientation was varied. Proprioceptive influences on visual perceptions of motion direction were shown by a dependence of perceptual errors on trunk and neck orientations when aligning to all axes. Furthermore, when aligning motion to an external line, the errors depended on orientation of the line in addition to trunk and neck orientations, but not when aligning to intrinsic axes or earth-fixed vertical in the presence of an external line. We conclude that the visual motion system defines direction relative to earth-fixed vertical and an external horizontal reference axis when available. The trunk-fixed A-P axis can be used to accurately define motion direction when operating without an external reference if a neutral trunk orientation is maintained.

UI	MeSH Term	Description	Entries
D007088	Illusions	The misinterpretation of a real external, sensory experience.	Autokinetic Effect,Autokinetic Illusions,Effect, Autokinetic,Illusions, Auditory,Illusions, Kinesthetic,Illusions, Tactile,Illusions, Visual,Auditory Illusion,Auditory Illusions,Autokinetic Effects,Autokinetic Illusion,Effects, Autokinetic,Illusion,Illusion, Auditory,Illusion, Autokinetic,Illusion, Kinesthetic,Illusion, Tactile,Illusion, Visual,Illusions, Autokinetic,Kinesthetic Illusion,Kinesthetic Illusions,Tactile Illusion,Tactile Illusions,Visual Illusion,Visual Illusions
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009039	Motion Perception	The real or apparent movement of objects through the visual field.	Movement Perception,Perception, Motion,Perception, Movement
D009949	Orientation	Awareness of oneself in relation to time, place and person.	Cognitive Orientation,Mental Orientation,Psychological Orientation,Cognitive Orientations,Mental Orientations,Orientation, Cognitive,Orientation, Mental,Orientation, Psychological,Orientations,Orientations, Cognitive,Orientations, Mental,Orientations, Psychological,Psychological Orientations
D010775	Photic Stimulation	Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.	Stimulation, Photic,Visual Stimulation,Photic Stimulations,Stimulation, Visual,Stimulations, Photic,Stimulations, Visual,Visual Stimulations
D011187	Posture	The position or physical attitude of the body.	Postures
D011434	Proprioception	Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.	Labyrinthine Sense,Position Sense,Posture Sense,Sense of Equilibrium,Vestibular Sense,Sense of Position,Equilibrium Sense,Sense, Labyrinthine,Sense, Position,Sense, Posture,Sense, Vestibular
D011597	Psychomotor Performance	The coordination of a sensory or ideational (cognitive) process and a motor activity.	Perceptual Motor Performance,Sensory Motor Performance,Visual Motor Coordination,Coordination, Visual Motor,Coordinations, Visual Motor,Motor Coordination, Visual,Motor Coordinations, Visual,Motor Performance, Perceptual,Motor Performance, Sensory,Motor Performances, Perceptual,Motor Performances, Sensory,Perceptual Motor Performances,Performance, Perceptual Motor,Performance, Psychomotor,Performance, Sensory Motor,Performances, Perceptual Motor,Performances, Psychomotor,Performances, Sensory Motor,Psychomotor Performances,Sensory Motor Performances,Visual Motor Coordinations
D002490	Central Nervous System	The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.	Cerebrospinal Axis,Axi, Cerebrospinal,Axis, Cerebrospinal,Central Nervous Systems,Cerebrospinal Axi,Nervous System, Central,Nervous Systems, Central,Systems, Central Nervous