TIME-COURSE OF SEMANTIC ACTIVATION IN THE CEREBRAL HEMISPHERES

Recent visual half-field studies using relatively long stimulus onset asynchronies (SOAs) and non-associated category members (e.g. deer-pon y) as word pair stimuli have indicated that with a low proportion of r elated stimuli, automatic priming of non-associated category informati on is larger in the right than in the left hemisphere [Chiarello and c o-workers]. The present study examined semantic priming of non-associa ted category members, with a low proportion of related stimuli in the visual fields/hemispheres across SOAs of 165, 250, 500, and 750 msec. Eighty normal, right-handed subjects were tested (20 subjects/SOA). Th e results revealed a left hemisphere advantage in priming at the 165 m sec SOA, whereas the right hemisphere advantage reported in earlier st udies was observed at the longest 750 msec SOA only. The results chall enge the view that a larger range of related meanings is activated in the right than in the left hemisphere. Rather, the time course of sema ntic activation may be different in the hemispheres. (C) 1997 Elsevier Science Ltd.