The Neural Bases of Subliminal Priming

Abstract Psychologists have long reported that words that are made invisible by forward and backward masking can nevertheless cause behavioral priming effects. Functional neuroimaging can now be used to explore the neural bases of masked priming. Subliminal priming causes reduced activation in multiple areas (fusiform gyrus, intraparietal sulcus, and motor cortex), in direct correspondence with behavioral manifestations of priming at the orthographic, semantic, and motor level. This implies that a whole stream of processors can operate unconsciously. The neural code in each area can be assessed by varying prime-target relations. A simple mathematical framework is proposed that tentatively relates priming at the voxel level with the shape of the tuning curves of single neurons in the underlying tissue.