Action priming is linked to visual perception in continuous flash suppression

Visual prime stimuli can affect the processing of following target stimuli even if their visibility is reduced due to visual masking. Prime visibility depends on the stimulus parameters of the prime and those of the mask. Here we explored the effects of prime stimuli and modulated their visibility by continuous flash suppression (CFS). CFS reduces the visibility of a stimulus presented to one eye by simultaneously presenting a series of high-contrast masking stimuli to the other eye. We manipulated the strength of CFS effects on perception and examined how action priming effects of the masked stimuli varied under the same conditions. Prime visibility was modulated by the contrast of the primes (Experiments 1 and 2), the contrast of the masks (Experiments 2 and 3), and by the stimulus onset asynchrony between prime and target stimuli (all experiments). Surprisingly, action priming effects were modulated by these experimental variables in a parallel way. In addition, individual differences between participants in prime visibility correlated with individual differences in action priming. Our findings suggest that action priming and prime perception depend in similar ways on prime contrast, mask contrast, stimulus onset asynchrony, and individual dispositions in CFS. These findings distinguish CFS from other perceptual suppression techniques, such as backward masking, that allow reducing prime visibility without parallel effects on action priming. Our results corroborate the view that CFS interferes with visual processing at early stages in the cortical hierarchy with similar effects on later processing for perception and action.