Jc. Culham et P. Cavanagh, MOTION CAPTURE OF LUMINANCE STIMULI BY EQUILUMINOUS COLOR GRATINGS AND BY ATTENTIVE TRACKING, Vision research, 34(20), 1994, pp. 2701-2706
Two experiments demonstrated motion capture of luminance-defined dots
by gratings with no net luminance-based motion. In a series of two-fra
me experimental trials, we superimposed bright dots and a color gratin
g rotating in opposite directions. Capture was observed at equiluminan
ce and was facilitated by the presence of color in gratings over a ran
ge of luminance contrasts. In a second experiment, observers noted tha
t when a counterphase grating was tracked in either direction with att
ention, the superimposed dots were captured in that direction. These r
esults suggest motion capture is supported not only by luminance-based
motion, but also by color- and attention-based motion. Indeed, we sug
gest that the most parsimonious explanation is that all capture is med
iated by attention.