Detecting the displacement of periodic patterns.
Observers were asked to detect the direction of displacement of a 30 c/deg grating. They were virtually unable to perform this task when the component was presented alone but when either a 28 or a 32 c/deg component (neither of which moved) was added to the 30 c/deg component observers were extremely sensitive to displacements of the 30 c/deg component. These results suggest that the detection of displacements cannot take place within narrow-band spatial channels, but relies on a mechanism which compares the output of channels in different spatial positions.
D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010507:Periodicity; D012684:Sensory Thresholds / Q000502:physiology