CROSS-MODAL SEMANTIC PRIMING - A TIME-COURSE ANALYSIS USING EVENT-RELATED BRAIN POTENTIALS

In two experiments, the time-course of behavioural and electrophysiological measures of semantic priming were examined between the visual and auditory modalities. In Experiment 1, auditory targets (words and pseudowords) were paired with visual prime words that onset either simultaneously with the target (0 msec stimulus onset asynchrony, SOA) or at one of two delays (200 and 800 msec SOA). Subjects made speeded lexical decisions to the auditory targets. Large priming effects were found across the three SOAs for reaction time and the N400 effect (the difference between related and unrelated target words). In Experiment 2, auditory primes were paired with visual targets. Here significant behavioural priming was found across the SOAs (larger for 0 and 800 msec), but the N400 effect was significant only for the 200 and 800 msec conditions. It is suggested that the data are most consistent with an amodal semantic system that is tapped by separate modality specific encoding processes.