Unconscious processing of facial expression as revealed by affective priming under continuous flash suppression

Whether emotional information from facial expressions can be processed unconsciously is still controversial; this debate is partially due to ambiguities in distinguishing the unconscious-conscious boundary and to possible contributions from low-level (rather than emotional) properties. To avoid these possible confounding factors, we adopted an affective-priming paradigm with the continuous flash suppression (CFS) method in order to render an emotional face invisible. After presenting an invisible face (prime) with either positive or negative valence under CFS, a visible word (target) with an emotionally congruent or incongruent valence was presented. The participants were required to judge the emotional valence (positive or negative) of the target. The face prime was presented for either a short (200 ms, Exp. 1) or a long (1,000 ms, Exp. 2) duration in order to test whether the priming effect would vary with the prime duration. The consistent priming effects across the two priming durations showed that, as compared to their incongruent counterparts, congruent facial expressions can facilitate emotional judgments of subsequent words. These results suggest that the emotional information from facial expressions can be processed unconsciously.