title: A simple integrative method for presenting head-contingent motion parallax and disparity cues on intel x86 processor-based machines.
abstract: Rogers and Graham (1979) developed a system to show that head-movement-contingent motion parallax produces monocular depth perception in random dot patterns. Their display system comprised an oscilloscope driven by function generators or a special graphics board that triggered the X and Y deflection of the raster scan signal. Replication of this system required costly hardware that is no longer on the market. In this paper the Rogers-Graham method is reproduced with an Intel processor based IBM PC compatible machine with no additional hardware cost. An adapted joystick sampled through the standard game-port can serve as a provisional head-movement sensor. Monitor resolution for displaying motion is effectively enhanced 16 times by the use of anti-aliasing, enabling the display of thousands of random dots in real-time with a refresh rate of 60 Hz or above. A color monitor enables the use of the anaglyph method, thus combining stereoscopic and monocular parallax on a single display without the loss of speed. The power of this system is demonstrated by a psychophysical measurement in which subjects nulled head-movement-contingent illusory parallax, evoked by a static stereogram, with real parallax. The amount of real parallax required to null the illusory stereoscopic parallax monotonically increased with disparity.
authors.affiliation: Department of Psychology, Rutgers University, Piscataway, NJ 08854, USA. janos@lvr.rutgers.edu
authors.forename: J
authors.initials: J
authors.lastname: Szatmary
authors.forename: I
authors.initials: I
authors.lastname: Hadani
authors.forename: B
authors.initials: B
authors.lastname: Julesz
mesh_terms: D016288:Computer Terminals; D003867:Depth Perception / Q000502:physiology; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008838:Microcomputers; D009039:Motion Perception / Q000502:physiology*; D009903:Optical Illusions; D011601:Psychophysics / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D015357:Vision Disparity / Q000502:physiology*