Orthographic neighborhood effects in the right but not in the left cerebral hemisphere

Two lexical decision experiments investigated orthographic neighborhood effects in the hemispheres. In the first experiment, lexical decision was affected by orthographic neighborhood size when stimuli were presented to the right hemisphere (RH) but not to the left hemisphere (LH). In a four-field masked-prime lexical decision task (Experiment 2), a larger shared orthographic neighborhood between prime and target facilitated lexical decision in the RH but not in the LH. The patterns of activation invoked in the two cerebral hemispheres by a written word and its orthographic neighbors may be qualitatively different.