Figure 1.

Experimental methods. (A) In experiment 1, observers viewed high contrast dynamic visual noise for varying durations and pressed one button when their visual snow reappeared on the adapted side, and pressed another button when the snow on the two sides appeared the same. (B) In experiment 2, observers also adapted to a pattern of stripes (defined by a Gabor function) and were tested either with visual snow or a low contrast Gabor pattern, again pressing a button when both sides of the display appeared the same.