Subliminal affective priming changes the 'feeling' towards neutral objects in infancy

In everyday life, our preferences are governed by influences that we are frequently not aware of. Studies investigating visual subliminal priming have shown that emotions are particularly able to modulate the affective judgments both at a behavioural and neural level. In this study, we investigated whether emotional unconscious learning is a core feature of human development, by testing infants as young as 3 months of age on a subliminal affective priming task, in which infants were primed with subliminal happy and angry faces (Experiment 1) or subliminal neutral and scrambled faces (Experiment 2), followed by two neutral objects. We found that arousal to the neutral objects - as indexed through skin conductance - changed when they were primed with faces displaying emotional valence, and particularly anger, but not when the face had a neutral expression. This change in physiological state only partially corresponded to a change in explicit behaviour - as indexed through looking times - suggesting that emotional unconscious learning likely influences explicit behaviour at later stages of development, when subcortical-to-cortical connections have strengthened.