Abstract
Responding to the direction of a target stimulus ("less than" or "greater than" signs) is facilitated by a congruent priming stimulus, if that prime is fully visible. However, if the prime is masked by a pattern consisting of features of both target stimuli, responses are actually slower following a congruent prime than following an incongruent prime—the "negative compatibility effect". Two theoretical explanations have been offered: (1) Partial activation, below the threshold of conscious awareness, is followed by self-inhibition (Eimer & Schlaghecken, 1998); (2) Priming is dominated by the "new" mask features rather than the "old" features shared with the prime (Lleras & Enns, 2004). Experiments in which the mask features were varied have yielded inconsistent results, possibly because dissimilarity between prime and mask features increases the likelihood of awareness of the prime. We attempted to address the issue by using different masking paradigms—metacontrast and object-substitution—in which masking depends less on featural similarity between mask and prime. In the metacontrast procedure, the prime was followed by a surrounding annulus at varying stimulus-onset asynchronies. In the object-substitution procedure, four flanking dots remained in view for 100 ms after the offset of the prime. We were unable to obtain a negative compatibility effect in either procedure. A particularly surprising result in the object-substitution procedure was a greater positive priming effect when the prime was masked than when it was not masked. This effect may be due to the task-relevance of the dot-mask in locating the target. Nonetheless, the result implies a paradoxical dissociation between attention-enhanced priming and conscious awareness of the prime.
Meeting abstract presented at VSS 2012