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.
Five pigeons were exposed to concurrent-chains schedules in which the terminal links were 3 pairs of fixed-time (FT) schedules while length of equal variable-interval (VI) schedules in the initial links were varied across conditions. Choice proportions for conditions of relatively short delay pairs increased as the length was shortened, confirming "initial-link effect". Subsequently, 2 of these 5 subjects were exposed to different types of the terminal-link schedule (FT, fixed-interval (FI), VI, and variable-time (VT) schedules) by using constant values of both the terminal-link delays and the length in the initial links. Although no systematic correspondence was found between relative rate of responding in the terminal links and choice proportions for VI and VT conditions, discrimination of the terminal-link shedules was found for FT and FI conditions by showing that FI scallop developed in those conditions. These results support implications of the delay-reduction hypothesis proposed by Fantino (1969).
Rats were treated with discriminative punishment in a 2 lever Skinner box, and their lever-pressings were reinforced by apple juice. In Experiment 1, responses to one lever (abbr. PUNs) were punished on a FR1 schedule in the presence of signal tone, but never to the other lever (abbr. UNPs). Punishment-component of this procedure was more distinct than CER-component, both of which composed discriminative punishment. PUNs were completely suppressed, but UNPs showed no conditioned suppression. Then, in Experiment 2, the rats were divided into two groups. PUNs of group V1 were punished on a VR10 schedule, while the V2 on a VR20 during the tone presentation. PUNs and UNPs of both groups showed little suppression. Finally, in Experiment 3, these two groups were yoked as to the electric-shock presentation. While in group V1 38% of the elecric-shocks received were response-noncontingent, in the V2 68%. UNPs of group V2 showed conditioned suppression, but not those of the V1. This suggests that the more indistinct the punishment-component is, the more easily the subjects acquire conditioned suppression against the signal stimulus.
Harris' proprioceptive change theory (1963, 1965, 1980) is not clear in the point which the term "proprioception" would contain the visual component or not. Sherrington, a neurophysiologist, used the term to classify the receptors based on their positions in the body. Emphasizing its functional aspect, J.J. Gibson gave it the meaning which contains visual characteristics. But this broadened terminology makes it impossible to estimate the Harris' theory. The present paper, therefore, focuses on the problem which the proprioception without any visual nature can represent the space or not. From the facts obtained in the visual transposition experiments and the close examination about the superiority of vision over other modalities and about the feature of the spatial perception of congenitally blinds, the following was concluded: The information from the proprioceptors alone could not represent spatial arrangements. It should be integrated in the "visual" space.
This study was concerned with the adaptation process of visually guided reaching movement under the prismic displacement vision to examine the effects of visual informations on reaching and grasping movement. Subjects were asked to reach and grasp a target with their right hand ten times repertedly while wearing up-down reversing goggles. For evaluating their movements, arm trajectory, grip size, hand velocity and hand acceleration were calculated every 1/30 sec on the basis of the screen images from the VTR tape by means of a microcomputer. The results indicated that the timing of speed control in reaching movement and the degree of maximum deceleration are programmed before the beginning of the movement. It was also suggested that the arm trajectory might be formed after the beginning of the movement using the visual informations since an arm trajectory was varied with the change of visual information. Lastly, this study could examined the usefulness of the analysis of time course in movement behavior for the study of adaptation to the reversed vision situations.