Abstract: The current study examined hemisphere asymmetry in selective processing of global and local properties and whether the two hemispheres are able to select simultaneously the global property of one compound stimulus and the local property of another compound stimulus. We presented one compound stimulus randomly in the left or right visual fields or two compound stimuli simultaneously in the left and right visual fields, respectively. Experiment 1 showed that reaction times (RTs) to global or local targets did not differ between the left and right visual field stimuli in the unilateral presentation condition. However, RTs to local targets were shorter to the right than left visual field stimuli in the bilateral presentation condition. In Experiment 2 subjects detected global or local targets that appeared in both hemifields. We found that RTs were shorter when targets appeared at the same than different levels of compound stimuli presented simultaneously in both hemifields. The results suggest a left hemisphere advantage in local processing in the bilateral presentation condition. Moreover, it is easier to select targets at the same than different levels of two compound stimuli presented bilaterally.

Key words: compound stimulus, global property, local property, hemisphere