Abstract

Helen Neville has gathered ERP data suggesting that accessing an “implicit” memory system produces a qualitatively different kind of ERP wave than does accessing our “explicit” conscious memory system. These results corroborate the hypothesis that an early anterior priming effect indexes activity of a system specialized for words, while a later posterior priming effect indexes access to general, episodic representations of words. Moreover, she saw no effects in the masked paradigms using pseudo-words, further supporting the notion of an early lexicon. However, we might not see any effects because the tasks use stimuli too complicated for an early automatic system to encode rapidly. Hence, masked priming effects for novel stimuli might be seen immediately with very simple input patterns. The following series of experiments was designed to test this hypothesis, as well as to try to differentiate the supposed early lexicon from other sorts of early access memory systems and to characterize more fully the capabilities of these early systems. In particular, ERP waveforms are compared for unmasked and masked priming conditions using simple 5-line visual patterns in experiments requiring subjects to make rapid decisions concerning the physical structure of the shapes