Hemispheric differences in grammatical class

Although a number of studies have examined lexical asymmetries in hemispher ic processing, few have systematically investigated differences between nou ns and verbs. Lateralization effects of grammatical class were examined by presenting nouns and verbs of both high and low frequency to either the rig ht or left visual field. Results from both a noun/verb categorization and a lexical decision task revealed a significant visual field by grammatical c lass interaction. Further analyses revealed that verbs were processed faste r in the left compared to the right hemisphere, while there was no hemisphe ric advantage for the processing of nouns. The present study provides new e vidence for the role of grammatical class in lexical processing. (C) 1999 A cademic Press.