Levels of sentence constraint and lexical decision in the two hemispheres

This study used a lexical decision-priming paradigm to investigate the relative sensitivity of the two cerebral hemispheres to linguistic constraint. Level of constraint of syntactically and semantically correct priming sentences was determined by the Cloze procedure and constraint was manipulated by means of these sentences. High-, medium-, and low-constraining as well as neutral incomplete sentences were presented centrally prior to the appearance of a target word or nonword either to the left or to the right visual field of sixteen righthanded subjects. The hypothesis tested was that the left hemisphere benefits more from linguistic constraint than the right hemisphere. Although reaction time data generally supported this hypothesis, the right hemisphere also seemed to benefit from the constraint produced by high-constraint sentences. The relevance of these findings to the manner in which the two hemispheres process different kinds of linguistic material is discussed.