Diffusion Model-based Understanding of Unconscious Affective Priming in Continuous Flash Suppression

Affective states influence our decisions even when processed unconsciously. Continuous flash suppression (CFS) is a new variant of binocular rivalry that can be used to render the prime invisible and thus unconscious. Nonetheless, it is unclear how prior information from emotional faces provided by CFS influences subsequent decision making. Here, we employed the CFS priming task to examine the effect of nonconscious information on the evaluation of target words as either positive or negative. The hierarchical diffusion model was used to investigate the underlying mechanisms. Two experiments were performed to investigate the effects of facial identity and facial expression. As a result, a significant affective priming effect on response time was observed only for angry faces but not happy and neutral faces. The results of diffusion model analyses revealed that both the drift rate and nondecisional process are accountable for the ‘positive bias’ - the processing advantage of positive over negative stimuli. Priming effects of facial identity were mapped onto the drift rate and eliminated ‘positive bias’. Meanwhile, positive emotional faces increased the nondecision time with negative target words. The model-based analysis implies that both facial identity and emotion are processed under CFS.