Spatial structure of the frequency doubling illusion

Abstract

We sought to determine (1) the perceived spatial frequency of flickering sinusoidal gratings as a function of temporal frequency at contrasts down to detection threshold levels, and (2) the influence of two different matching criteria on reported size matches to identify changes in the apparent spatial structure introduced by counterphase flicker. To determine if spatial structure was observable at detection threshold contrasts, we simultaneously measured contrast detection and orientation-identification thresholds of flickering gratings. We then measured the apparent size of flickering grating bars at sub-threshold to supra-threshold contrast levels using two matching criteria: (1) by adjus..