LEVEL OF PROCESSING EFFECTS ON HEMISPHERIC ASYMMETRIES WITH KANA (JAPANESE PHONETIC SYMBOLS) WORDS

Two experiments were conducted to examine the role of levels and types of higher-order processing to which the stimulus was subjected. In the experiment 1, two different physical identity matches with Kana (Japanese phonetic symbols) words, one involving two operations while the other involves one operation, were required, and no visual field difference was found though two operations task yielded longer RTs than in one operation task. Experiment 2, where two different name identity matches, one involving linguistic and spatial operations while the other involves linguistic operation, revealed that (1) a significant right visual field advantage is found in the linguistic operation task; however, this tendency disappears in the two operation task, (2) the two operation task yields longer RTs than the one operation task does. These results suggest that the levels of information processing and types of higher-order processing (spatial operation in this study) are important factors in determining hemispheric asymmetry effects.