In order to clarify the characteristics of perception of visual space in the early or congenitally blind who have just gained sight after surgery, a series of experiments covering a period of over 10 years were conducted. Subject KT in this paper, who lost her sight binocularly due to congenital cataract, received the operation on her left eye at the age of 15. The following results were obtained: (1) The perceived size of an object placed at various distances on a table decreases when the physical distance exceeds 20cm approximately. The ratio of perceived sizes to physical distances demonstrates that the size constancy is not so high as that of the normally sighted adult. (2) Color perception was slightly easier than that of shape, but it became difficult when the observation distance (D) extended 60cm and when the size of color paper was small. (3) Identification of the shape of a figure was difficult when the figure was presented at D>35cm. At a near distance she could scan the shape as a whole, but at a far distance, KT had to employ the strategy of partial scanning.
There exists a considerable literature on the early development of visual perception, but much less research on the development of eye movement per se has been reported. This paper reviews the basic research on the early development of the saccades and smooth pursuit movements of the eye. The following topics are discussed: the developmental changes in saccadic latency, the existence of slow saccades and multiple saccades during the early stages of development, and the problem of whether neonates can pursue moving targets smoothly or not. Research on the developmental changes in smooth pursuit eye movements during childhood are also reviewed, and it is pointed out that less quantitative research has been done with children than with infants. In research on the development of eye movements, attentional and arousal factors of the subjects play a very important role. Finally, it is pointed out that the improvement of measuring techniques is neccesary.
In order to investigate an interaction between auditory and visual memory, a serialrecall experiment was conducted. Ten random digits were presented, auditorily, visually and audio-visually at rapid (0.8sec.) and slow (2.4sec.) rates. The peculiarity of the serialposition curve on each modality was summarized as follows: (1) The performance at a primacy portion under a visual presentation was better than that under an auditory one. The primacy portion under an audio-visual presentation at rapid and slow rates was consistent with that under the auditory and the visual presentation, respectively. (2) At both rapid and slow rates, little recency effect appeared under the visual presentation, whereas a great recency effect appeared under the auditory one as well as the audio-visual one. It was concluded that (1) the primacy effect under audio-visual presentation at rapid and slow rates results from the auditory memory and the visual one, respectively; and (2) the recency effect under audio-visual presentation at both rates results from the auditory memory.