When visibility and priming have an inverse relationship: A successful replication of Vorberg et al., 2003

In this study, we replicate a striking dissociation of consciousness from action. The dissociation comes from Vorberg et al. (2003) who explored whether metacontrast-masked stimuli still prime subsequent actions. In metacontrast masking, stimuli are rendered less visible by increasing the time between it and a subsequent mask (ISI). Vorberg et al. demonstrated that as stimuli were less visible with longer ISI, they nonetheless exerted a greater priming effect on motor responses to subsequent targets. This stunning dissociation is highly persuasive, as it obviates the usual critiques of subliminal priming effects. To our knowledge, it remains unreplicated. Here we report a successful replication: in metacontrast masking, prime visibility decreases initially with ISI while motor priming increases. Our replication study has almost 5x as many individuals and provides confirming evidence for the dissociation. We provide an interpretation within Mishkin et al. (1983) ventral-and-dorsal stream processing model, and we show that individual differences in the effect are qualitative in that different individuals exhibit qualitatively different patterns.