Comparing sensitivity across different processing measures under metacontrast masking conditions

In the so-called metacontrast dissociation, masked primes with a target-congruent shape facilitate responses to visible targets, whereas masked shape-incongruent primes interfere with them, even if participants cannot successfully discriminate between masked imperative primes (comprising congruent and incongruent shape primes) and non-imperative primes (with a shape different from that of all targets). Previous research suggests that visual motion perception can be spared from metacontrast masking [Kolers, P. (1963). Vision Research, 3, 191-206]. Here, we confirmed that detection of visual rotation is spared to a larger degree than detection of visual shape (Experiment 1) and that even shapes of masked stimuli can be detected if the shape-detection task is easier (Experiment 2). Implications of our findings for the conclusion that performance in masked priming studies depends on processing of non-conscious inputs are discussed.