Detection in metacontrast.

Abstract

This study investigated metacontrast under a variety of stimulus and response conditions. The results show that (a) although the 1st stimulus in the metacontrast situation appears absent or very much darkened at certain intervals between the 1st and 2nd stimulus, it can be correctly detected by O employing both RT [reaction time] and forced-choice situations, (b) When the luminance of the 1st stimulus is set low relative to that of the 2nd stimulus, a monotonic function is obtained for both detection errors and choice reaction time (CRT), with maximal errors and longest CRTs at the shortest interval between the stimuli, (c) When the 2 stimuli are of equal luminance, increasing the rate of presentation to a point where the interval between 1st and 2nd stimuli within a pair equals the interval between successive pairs, increases the apparent brightness of the 1st stimulus.