Lateral differences in higher-order cognitive processing were investigated using a mental rotation task. Subjects were required to match rotated Kanji characters to upright Kanji. One group of subjects was given an advance cue with regard to the orientation of the comparison Kanji characters while the other group did not receive such a cue. Subjects showed faster reaction times for stimuli presented in the left visual field as compared with stimuli presented in the right visual field under the No-cue conditions. Subjects under the Cue conditions, however, showed superior performances for left visual field presentation only when smaller angles of rotation of the stimuli were used. When larger angle conditions of the stimulus rotation were employed, right visual field presentation produced faster reaction times. These findings were discussed in relation to the role of the left hemisphere in higher-order psychological processes.