Fluency and disfluency dissociate FN400 and N400 ERP components during recognition

Masked priming has been used to influence recognition memory familiarity by increasing or decreasing fluency. These manipulations affect Event-Related Potential (ERP) activity occurring 300-500 ms after the probe. In this article, several datasets from previously published studies were reanalyzed to investigate the effect of baseline period on ERP measurements and to determine whether two different ERP components occur during the 300-500 ms interval. In addition, a novel study was conducted to measure the effect of orthographically similar (OS) primes on ERP measures. The baseline period had little effect on ERP measures and OS word primes do not elicit disfluency effects when fluency-inducing primes are not part of the test sequence. Furthermore, three datasets provided evidence that prime effects and topography 300-400 ms was distinct from the activity occurring 400-500 ms. These effects are taken as strong evidence for models that argue fluency can affect two types of familiarity (i.e., relative and absolute familiarity, Mecklinger & Bader, 2020).