WHY SAFE IS BETTER THAN FAST - THE RELATEDNESS OF A WORDS MEANINGS AFFECTS LEXICAL DECISION TIMES

Past lexical decision studies investigating,o the number of meanings ( NOM) effect have produced mixed results. A second variable, the relate dness among a word's meanings, has not been widely studied. In Experim ent 1, Relatedness (High or Low), NOM (Many or Few), and nonword condi tion (legal nonwords or psuedohomorphones) were manipulated in lexical decision. No significant effects of NOM or Relatedness were observed in the legal nonword condition. However, in the pseudohomophone condit ion, Relatedness and NOM both produced significant main effects, and a n interaction. Words with few, unrelated meanings produced the slowest response times (RTs); all other words produced statistically equivale nt RTs. Results of the pseudohomophone condition of Experiment 1 were replicated in Experiment 2, except the main effect of NOM was not sign ificant. The overall unreliability of NOM effects in these (and previo us) experiments lead us to question the contribution of NOM to the obs erved interaction NOM metrics are often confounded with relatedness; w ords with many meanings tend to have highly related meanings. The resu lts show that relatedness among meanings can influence lexical decisio n performance; the challenge is now to explore alternative measures, o ther than simple enumeration. (C) 1997 Academic Press.