Abstract
The present study explores the role of motion in the perception of form from dynamic occlusion, employing color to help isolate the contribution of both visual pathways. Although the cells that respond to color cues in the environment usually feed into the ventral stream, humans can perceive motion based on chromatic cues. Additionally, the use of particular colors appears to selectively inhibit the activity in the dorsal system. For example, Seno, Sunaga, and Ito (2010) demonstrated that the color red can have an inhibitory effect on cells engaged in motion-processing. Thus, using the color red as a background feature could be an effective method for investigating magnocellular and parvocellular input in the perception of shapes defined by motion. Moreover, stimuli presented in grey supplies more information to the dorsal stream than a target presented in green and thus should result in color based performance differences. The current study was designed to use grey, green and red stimuli to successively limit the amount of information available to the dorsal stream pathway. Twenty-one participants identified shapes presented in grey, green, and red, defined by dynamic occlusion, and were then presented again in a static condition where the maximum occlusions were presented as before, but without motion. Results confirmed an interaction between the motion and static conditions insofar as when the speed of presentation increased, performance in the motion conditions became significantly less accurate than that of the static conditions. The grey and green motion conditions crossed static performance at the same point, whereas the red motion condition crossed at a much slower speed. These data are consistent with a model of neural processing in which the main visual systems share information; moreover, they support the notion that presenting stimuli in specific colors may help isolate perceptual pathways for scientific investigation.
Meeting abstract presented at VSS 2012