Effects of absolute mask energy and mask energy range on metacontrast suppression

In an experiment similar to one by Bernstein, Fisicaro, and Fox (1976), subjects were asked to judge the brightness of test stimuli in a metacontrast display. The energies of the test and of the mask varied orthogonally. Various experimental conditions differed with respect to the range of mask energies. Individually, the mask energies were generally weaker than the test energies. The results replicated the main findings of Bernstein et al. (1976) in that judgments of the test were negatively correlated with mask energy at short stimulus onset asynchrony (SOA) but positively correlated at long SOA. These effects were more pronounced when the masks were similar in energy range and level to the tests than when they were wider in energy range and weaker. In general, there was no evidence for the effects of trial-to-trial variation described by Hake, Faust, McIntyre, and Murray