LINGUISTIC PROCESSES IN THE 2 CEREBRAL HEMISPHERES - IMPLICATIONS FORMODULARITY VS INTERACTIONISM

Three experiments are reported on lexical decision to target stimuli p resented to the right or left visual field (RVF, LVF) following a vari ety of priming stimuli, words, incomplete sentences, and scrambled sen tences. Lexical decision performance is always superior for stimuli pr esented to the RVF. Primes always facilitate the discrimination of wor ds from nonword target stimuli presented to either visual field. Howev er, when the prime is a sentence which is completed syntactically and semantically by a target word (normal, congruent sentence), the facili tation for RVF presented targets is significantly greater than for LVF targets. When the prime is either: (1) a single word, (2) a nonstruct ured (scrambled) sentence, or (3) a noncongruent-related sentence, the difference in facilitation between RVF and LVF presented targets is m uch smaller. These data are discussed with respect to (1) the nature o f priming by sentences versus words, (2) language processing by the tw o hemispheres, and (3) modularity versus interactionism in language pr ocessing.