BRAIN POTENTIALS ELICITED BY WORDS - WORD-LENGTH AND FREQUENCY PREDICT THE LATENCY OF AN EARLY NEGATIVITY

Prior work has suggested that open-and closed-class words elicit negat ive components in the event-related potential (ERP) that differ in tim ing and scalp distribution. We tested this hypothesis against the poss ibility that the word-class effects are attributable to quantitative d ifferences in word length and frequency. Event-related brain potential s (ERPs) were recorded from 13 scalp sites while participants read nor mal or scrambled prose. ERPs were averaged as a function of word class (open vs. closed) and grammatical category (articles, nouns, verbs, e tc.). Regression analyses indicated that the latency of an early-occur ring negative component was highly correlated with the mean length and normative frequency of words in each grammatical category. Stronger c orrelations were observed in the scrambled prose condition than in the normal prose condition. Differences in the scalp distributions of the se negativities were found to be a function of grammatical category ra ther than word class. These results are taken to be inconsistent with the claim that open-and closed-class words elicit qualitatively distin ct negativities. (C) 1997 Elsevier Science Ireland Ltd.