What Can Motion Aftereffects Teach us About Action and Attention?

Rob Gray

Nissan Cambridge Basic Research
Cambridge, MA

The ability to selectively adapt the human visual system has been used as a psychophysical tool to investigate many basic aspects of human vision (e.g. spatial frequency filtering and motion opponency). But, does selective adaptation have any important effects on our behavior in the world outside the laboratory? Can it be used as tool for studying more complex phenomenon like perceptual-motor control and visual attention? In the first part of this talk, I will discuss two new effects of motion adaptation on visually guided motor action: (1) Following prolonged exposure to retinal image expansion produced by simulated driving on an empty road, motion adaptation can cause a driver to overestimate the time to collision with other cars. This overestimation can dramatically alter the timing of overtaking and passing maneuvers; (2) Adaptation to expansion during driving can also increase the time required to detect approaching objects. This increase in detection time can delay the initiation of braking, increasing the risk of a rear-end collision. Along with considering the important practical implications, I will demonstrate how these aftereffects can be used as a research tool for understanding the control of visually guided actions. Finally, I will discuss experiments examining the attentional modulation of these aftereffects and consider the role of attention in the processing of motion-in-depth.

The lecture will take place:

in the Lecture Hall, Room 203, 44 Cummington St.
on Tuesday, October 17, 2000
at 4:00 pm