Ms. Georgiades et Jp. Harris, Attentional diversion during adaptation affects the velocity as well as the duration of motion after-effects, P ROY SOC B, 267(1461), 2000, pp. 2559-2565
Citations number
38
Categorie Soggetti
Experimental Biology
Journal title
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
The effects of diverting attention on early motion processing in human visi
on were studied with a selective adaptation technique. The velocity of moti
on after-effects (MAEs) produced on a stationary test grating after prolong
ed exposure to drifting luminance-modulated gratings was measured by matchi
ng MAE velocity with that of another physically moving grating. Initial MAE
velocities decreased and their rate, of decay increased with the distance
of the adapting and test: gratings from the fixation point. When attention
was diverted from the adapting grating, by having subjects process the inte
rmittently changing digit which formed the fixation paint, initial MAE velo
cities were reduced and rate of decay increased, with the largest effect of
diversion being found for gratings near the fixation point. The effects of
varying attention mimic those of varying adapting duration, rather than ad
apting contrast or velocity and appear to reflect a genuine change in motio
n-processing mechanisms.