On the locus of the semantic satiation effect: Evidence from event-relatedbrain potentials

The present study sought to determine whether semantic satiation is merely a by-product of adaptation or satiation of upstream, nonsemantic perceptual processes or whether the effect can have a locus in semantic memory. This was done by measuring event-related brain potentials (ERPs) in a semantic w ord-detection task involving multiple presentations of primes and critical related and unrelated words in three experiments involving visual (Experime nt 1) and auditory (Experiments 2A and 2B) stimuli. Primes varied in their type case (Experiment 1) or pitch (Experiment 2B) in order to discourage se nsory adaptation. Prime satiation and relatedness of the primes to the crit ical word had interacting effects on ERP amplitude to critical words, parti cularly within the time-window of the N400 component. Because numerous stud ies have indicated a role for the N400 in semantic processing, modulation o f the N400 relatedness effect by prime satiation (with little or no contrib ution from perceptual adaptation) suggests that semantic memory can be dire ctly satiated, rather than the cost to semantic processing necessarily resu lting from impoverishment of perceptual inputs.