JOURNAL OF MEMORY AND LANGUAGE 37, 118–139 (1997) ARTICLE NO. ML972510 How Complex Simplex Words Can Be

A series of experiments investigated components of the word frequency effect in visual lexical decision, progressive demasking, and subjective frequency ratings. For simplex, i.e., monomor-phemic, nouns in Dutch, we studied the effect of the frequency of the monomorphemic noun itself as well as the effect of the frequencies of morphologically related forms on the processing of these monomorphemic nouns. The experiments show that the frequency of the (unseen) plural forms affects the experimental measures. Nouns with high-frequency plurals are responded to more quickly in visual lexical decision, and they receive higher subjective frequency ratings. However, the summed frequencies of the formations in the morphological family of a given noun (the compounds and derived words in which that noun appears as a constituent) did not affect the experimental measures. Surprisingly, the size of the morphological family, i.e., the number of different words in the family, emerged as a substantial factor. A monomorphemic noun with a large family size elicits higher subjective frequency ratings and shorter response latencies in visual lexical decision than a monomorphemic noun with a small family size. The effect of family size disappears in progressive demasking, a task which taps into the earlier stages of form identification. This suggests that the effect of family size arises at more central