Influence of word class proportion on cerebral asymmetries for high- and low-imagery words.

It has been claimed that the typical RVF/LH advantage for word recognition is reduced or eliminated for imageable, as compared to nonimageable, nouns. To determine whether such word-class effects vary depending on the stimulus list context in which the words are presented, we varied the proportion of high- and low-image words presented in a lateralized lexical decision task (0, 25, 50, 75, or 100% high image). Although the RVF/LH advantage for high-image words was unaltered by word-class proportion, a significant linear trend was obtained for the low-image words such that the RVF/LH advantage increased as the proportion of low-image words increased. We discuss the implications of these findings for models of how lexical processing is distributed across hemispheres.