Biomedical subjects

Nam-Gyoon Kim

Publications and source records attributed to Nam-Gyoon Kim.

3 recordsLinked to original sources

PubMed2006

Multiple sources of information and time-to-contact judgments.

Four experiments examined how the visual system deals with multiple information sources for perceiving dynamic events. Two tau-type optical variables, one defined by the expanding object's image and the other defined by the expanding angular extent composed of the line of sight and the object's shadow, were manipulated in time-to-contact judgments. When the information specified by both variables was consistent, little perceptual accuracy was gained by having two information sources. When the two sources conflicted, perceptual accuracy deteriorated in proportion to the degree of conflict. Based on these results, we concluded that the visual system integrates multiple sources of event-specific information, and that a reliable source of information can be the shadows cast by moving objects.

Adult↗

PubMed2006

Active steering along corrugated surfaces.

A study is reported of the effect of dynamic occlusion that arises during locomotion over corrugated surfaces and its facilitating role on the control of locomotion, especially in cluttered environments. Surfaces varied in degree of corrugation and type of texture. Heading accuracy was assessed by having participants perform an active steering task. Results demonstrated the advantage of texture-mapped image surfaces over discrete element surfaces in the corrugated conditions. Observers appear to exploit accretion and deletion of optical texture at the occluding edge to extract and use information about heading direction for the control of movements in cluttered environments.

Cues↗

PubMed2002

Perceiving curvilinear heading in the presence of moving objects.

Four experiments were directed at understanding the influence of multiple moving objects on curvilinear (i.e., circular and elliptical) heading perception. Displays simulated observer movement over a ground plane in the presence of moving objects depicted as transparent, opaque, or black cubes. Objects either moved parallel to or intersected the observer's path and either retreated from or approached the moving observer. Heading judgments were accurate and consistent across all conditions. The significance of these results for computational models of heading perception and for information in the global optic flow field about observer and object motion is discussed.

Analysis of Variance↗