One commonly used paradigm to investigate the scope and limits of unconscious processing is the masked priming paradigm. The concept of this paradigm is that the prime stimulus facilitates or inhibits a speeded reaction to the target stimulus even when the prime was not consciously perceived. The prime’s visibility is typically assessed with a subjective or objective measure on a trial-by-trial basis. Our study started from the observation that these report-based paradigms qualify as dual-tasking situations. Recent work has shown that semantic as well as response priming effects are affected by dual-tasking costs. In our study, we aimed to systematically estimate the influence of dual-tasking costs on masked response priming effects. In a small-N within-subject experiment using metacontrast masking, participants discriminated the target by quickly pressing one of two keys, and then indicated the subjective visibility of the prime stimulus, either by vocal response or by key-press (factor “response modality”). The subjective measure consisted of a perceptual awareness scale (PAS) with either two or four items (factor “task complexity”). We predicted a
combined effect of both factors on the extent of response priming, i.e., an
interaction between the demands of the prime- and target-related tasks at the motor execution stage and the central processing stage. Preliminary data show more dual-tasking costs in form of increased reaction times for the manual response modality conditions as well as for the higher task complexity conditions. Based on our data, we will formulate recommendations for masked priming paradigms involving dual-tasking situations.