Proceedings of the Annual Meeting of the Cognitive Science Society

For a visual word to be recognised it must be singled out from a m o n g all other possible candidates. T h e less distinct a lexical entry is the more candidates there will be competing with it, and so recognition will be inhibited. In opposition to this view the fin- dings of Andrews (1989,1992) show a facilitatory ef- fect of neighborhood size; low frequency words which bore orthographic similarity to m a n y other words were recognised more quickly, than those with fewer neighbors. Since neighborhood size as determined by Coltheaurts " N " metric was designed as essentially a measure of lexical similarity, Andrews result could be interpreted as evidence for lexical level facilitation. In the present experiments w e repeat both the Idt and naming studies of Andrews using a more tightly controlled stimulus set. Only in L D T are her results supported, in naming w e find no facilitatory effect of neighborhood size. W e discuss w h y any truly lexical level facilitation is inherently improbable.