Conventionalisation of novel metaphors: a shift in hemispheric asymmetry.

According to recent psycholinguistic theory conventional metaphors may be understood via categorisation whereas novel metaphors are understood via comparison processes. Furthermore, behavioural evidence suggests that the process of conventionalising novel metaphors is accompanied by a shift from comparison to categorisation. However, changes in correlative neuropsychological processing as a result of the conventionalisation of novel metaphors have not been tested. Previous studies have provided evidence for special right hemisphere involvement in the comprehension of two-word novel, but not conventional, metaphoric expressions. On the basis of the latter evidence we used the divided visual field technique to test the possibility that the conventionalisation of novel metaphors will be accompanied by a shift from right to left hemisphere processing. The results suggest that repeated exposure to novel metaphoric stimuli changes the pattern of hemispheric asymmetry.