CATEGORICAL PRIMING IN THE CEREBRAL HEMISPHERES - AUTOMATIC IN THE LEFT-HEMISPHERE, POSTLEXICAL IN THE RIGHT-HEMISPHERE

Automatic and postlexical semantic processing in the cerebral hemisphe res was studied by presenting categorically related but nonassociated word pairs (e.g., TABLE-BED) to the left visual field (LVF) or to the right visual field (RVF) in semantic priming experiments. Experiment 1 examined automatic priming across stimulus onset asynchronies (SOAs) of 165 and 750 ms with a low proportion of related pairs and a low non word ratio, employing a GO-NOGG lexical decision task. In contrast to an earlier view that a larger range of meanings is automatically activ ated in the right than in the left hemisphere, priming was observed in the RVF/left hemisphere only. SOA did not exert an; effects. In Exper iment 2, postlexical semantic matching of the prime and the target was encouraged by requiring subjects to respond to both of them at the sa me time. Now there was priming in the LVF, suggesting that a postlexic al matching process works in the right hemisphere. The earlier studies showing a right hemisphere advantage in categorical priming are reint erpreted according to the postlexical right hemisphere hypothesis. (C) 1998 Elsevier Science Ltd. All rights reserved.