Subliminal Perception of Words and Faces

The aims of this study were to determine whether stimuli which cannot be detected consciously may nevertheless influence subjects' choices, and whether such an effect is dependent upon stimulus quality and the cerebral hemisphere involved in processing. We subliminally presented words (associated with left hemisphere processing) and faces (associated with right hemisphere processing) to each visual half-field. Subsequently, subjects had to choose among six items. The performance of subjects was compared to that of controls to whom only blank stimuli were presented. Subjects chose the correct word or face significantly more often than controls. For words this effect was significant only when they were subliminally presented to the left hemisphere, whereas subliminal face processing was done by both hemispheres. Our results demonstrate that (i) subliminally presented stimuli influence subjects' choices and thus must have been perceived, and (ii) that cerebral dominance seems to play a role in subliminal perception.