The Word Frequency Effect for Open- and Closed-Class Items

A previous attempt (Segui, Mehler, Frauenfelder,&Morton, 1982) to assess in French the putative computational asymmetry between open- and closed-class words failed to reveal a difference in frequency sensitivity for these two types of words. In the present paper, two further lexical decision experiments are presented. The experimental conditions were chosen to maximise the chances of finding differences in frequency sensitivity between the two word classes (speeded responses and stimulus masking). Both experiments revealed strong frequency effects for open- and closed-class items and thus no asymmetry in frequency sensitivity. The implications of these results for both normal and aphasic populations are discussed