Metacontrast and simple reaction time: A reexamination

E. Ferber and D. Raab (see record) and subsequent investigators have reported that simple reaction time (RT) to a metacontrast-inducing combination of test and mask stimuli is more rapid than to either component (test or mask) alone. They concluded that simple RT is not affected by metacontrast. The present authors argue that their conclusion is not warranted. A test-mask combination normally should evoke faster RT than either test or mask alone because of the greater area and, hence, total energy of the combination. A more appropriate comparison is between the metacontrast-inducing combination and a combination of equal area and energy that does not induce metacontrast. This comparison was made in a study with 8 graduate students. 4 Ss gave equivocal results; RT to the 2 combinations and to its components were all equal, but 4 Ss showed faster RT to the non-metacontrast-inducing combination. The overall results indicate that metacontrast does affect simple RT. (PsycINFO Database Record (c) 2006 APA, all rights reserved).