Neighborhood effects on nonword visual processing in a language with shallow orthography.

Neighborhood size and neighborhood frequency were orthogonally varied in two experiments on Italian nonwords. In Experiment 1, an inhibitory effect of neighborhood frequency on visual lexical decision was found: The presence of one high-frequency neighbor increased response latencies and error rates to nonwords. By contrast, no effect of neighborhood size and no neighborhood size x neighborhood frequency interaction were found. In Experiment 2, a facilitatory effect of neighborhood size on nonword naming was shown: Naming latencies were faster when nonwords had a large neighborhood. In the naming experiment, there was no effect of neighbors' frequency and no neighborhood size x neighborhood frequency interaction. An additional role for bigram frequency was found whereas syllable frequency did not give any independent contribution. These results further corroborate the view that, in a language with transparent orthography like Italian, despite a substantial contribution of sublexical print-to-sound mapping due to the language's high regularity/consistency, reading aloud of nonlexical material may benefit from the contribution of the lexical component.