[Effects of learning experience to the visual field advantage on random form recognition]

In order to examine the effects of learning experience to the visual field advantage on random form recognition, two experiments were carried out with the successive matching task (Test). The learning task employed was to associate random forms with two letter nonsense words. In Exp. 1, 25 right-handed subjects participated in the five successive days to manipulate the levels of learning retention among them. In the first and third sessions, Tests (1, 2) followed the learning task. In the second and fourth sessions, only the learning task was carried out. In the fifth session, only Test 3 was conducted. In Exp. 2, the same subjects conducted only Test 4 at three months later, when their levels of retention were lowered. Results obtained were that shifts occurred from the left visual field advantage (LVF-A) for random form recognition in Test 1 to no visual field difference in Test 3 as the learning retention increased, and from no visual field difference to LVF-A again when the retention decreased in Test 4. The possibility as for the effects of learning experience in relation to hemispheric asymmetry was discussed.