Special Research Scientist (Matin)
General Area of Research
The influences on visual space perception and visually-guided sensorimotor behavior from the visual field as well as from other modalities.
Visual space perception and visually-guided sensorimotor behavior are primary aspects of our interactions with our environment. We study the influences on both from the visual field as well as from other modalities.
The study of the visual influences on egocentric space perception
Systematic changes of visual perception of elevation (VPEL), visual perception of orientation within the frontal plane (VPV), and the perception of visual pitch (PVP) have been measured from pitch or roll-tilt of the visual field consisted of 1-line, 2-line in darkness as well as of a complexly- structured, well-illuminated pitchroom. More recent experiments involve visual fields which are consisted of arrays of lines whose local and global orientations differ from each other and arrays of points. We also investigate the the visual influence on VPEL and VPV with joint systematic variations of eye position and inducing line horizontal eccentricity. These experiments allow us to study the important visual and extraretinal factors in egocentric space perception.
The study of manual pointing, matching, and reaching visual targets under illusory visual localization
Manual pointing, matching, and reaching to mislocalized objects under visual induction exhibit distance-dependence: with the unseen hand in the body’s midfrontal plane, pointing and matching are in errors that are essentially similar to the perceptual errors, but when the unseen hand is fully-extended, reaching is accurate; the effect is graded linearly with distance. By running experiments in which observers make manual height match to the perceived (or remembered) elevation of a target at variable distance first in the presence of both the inducing line and the visual target, then in the presence of either the visual target alone, the inducing line alone, or none of the inducing line and visual target, we are testing two alternative interpretation for the discrepancy between perception and action: the Disconnection Model and the Shifting Reference Frame Model.
- Ph.D., Columbia University, 1989
- Li, W., and Matin, L. (2005). Two wrongs make a right: Linear increase of accuracy of visually-guided manual pointing, reaching, and height-matching with increase in hand-to-body distance. Vision Research, 45, 533-550.
- Li, W., and Matin, L. (2005). Visually perceived vertical (VPV): induced changes in orientation by 1-line and 2-line roll-tilted and pitched visual fields. Vision Research, 45, 2037-2057.
- Li, W., and Matin, L. (2005). The Rod-and-frame effect: The whole is less than the sum of its parts. Perception, 34, 699-716.
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