1991 年 9 巻 2 号 p. 73-84
MM, an early blind subject, received an optical iridectomy in her right eye at the age of 12. Preoperatively, her right eye had only light perception. Immediately after the operation, she could distinguish brightness, but not color. In order to improve her visionsign system activity, we planned to develop her visual shape discrimination. The first task was the discrimination between a triangular and a circular light, which were projected onto an opaque glass screen. In spite of taking 6 months, she failed to reach the criterion of successful discrimination. On the final task following many kinds of experiments to explore her potential discrimination ability, she was asked to distinguish a black circular patch from a black triangular patch attached to a white paper through the matching-to-sample method. Although she did not reach the criterion of successful discrimination, it was observed that her activity of exploring the features of figure-area has gradually become a systematic one. A theoretical implication concerning the changes in her exploring activities is briefly discussed.