Neuroanatomical organization of perceptual memory: An fMRI study of picture priming

Neuroanatomical organization of perceptual representation in human memory s ystem is unclear primarily because it has been studied using paradigms that have both, perceptual and conceptual components (e.g., word stem completio n and word fragment completion). In the present experiment, functional magn etic resonance imaging (fMRI) technique was used to examine the pattern of cortical activation in a picture identification test in which subjects were asked to identify subliminally presented primed and novel pictures. This t est is a modification of the word identification test that is considered a "pure" form of perceptual priming. Results indicate that perceptual priming is associated with reduced activation in the extrastriate cortex and that the memory for subliminally presented stimuli is processed by the same brai n areas that process adequate stimuli. The activation pattern observed in p icture identification test is different from that reported in the experimen ts of conceptual priming, suggesting that perceptual and conceptual represe ntation of memory are supported by separate brain mechanisms. (C) 2000 Wile y-Liss, Inc.