Cite as:
Mezey L E, Curthoys I S, Burgess A M, MacDougall H G, Halmagyi G M, 2002, "Ocular torsion induced during settings of a visual line to perceived horizontal and vertical" Perception 31 ECVP Abstract Supplement

Ocular torsion induced during settings of a visual line to perceived horizontal and vertical

L E Mezey, I S Curthoys, A M Burgess, H G MacDougall, G M Halmagyi

High-precision video measures of 3-D eye position were recorded while the subject made settings of an LED bar subtending 20 deg to visually perceived horizontal (VPH) or visually perceived vertical (VPV) using the method of adjustment (bar speed 4.5 deg s^-1). Settings were made in an otherwise darkened room or in the light. Subjects were required to maintain fixation of the central LED while making settings from start positions either side of horizontal or vertical to VPH and VPV, respectively. Results indicated that even a single visual line can induce substantial amounts of torsional rotation of the eye relative to subject's baseline torsional variation in both dark and light. The gain of these eye movements varied between subjects, but bar settings to VPH consistently induced a greater amount of torsion than settings to VPV. Since it is known that the torsional position of the eye influences the perception of visual orientation, our results imply that the psychophysical method used to study the perception of orientation may itself influence the measure of perceived visual orientation.

[Supported by a grant from NHMRC of Australia.]

These web-based abstracts are provided for ease of seaching and access, but certain aspects (such as as mathematics) may not appear in their optimum form. For the final published version of this abstract, please see
ECVP 2002 Abstract Supplement (complete) size: 1753 Kb