The orthographic neighbourhood frequency effect in French: a letter-case manipulation study.

The neighbourhood frequency effect was investigated by a letter-case manipulation of French words presented in the go/no-go lexical decision task. Accented words were presented both in lower-case letters with written accents and upper-case letters with no written accents, two usual typographies in French. This procedure addressed the stimulus-matching problem by using intra-word comparisons as some words have different orthographic neighbourhoods in the two cases. Neighbourhood frequency was varied across case change for half of the words while it was held constant for the other half. The results showed an interaction between letter-case and neighbourhood constancy, so the inhibitory neighbourhood frequency effect could not be attributed to interstimulus comparisons or to typographical change. Implications are discussed in current models of visual word recognition.