The Disappearance of Steadily Fixated Visual Test Objects

摘要

In 1951 I was lucky to apply for and be accepted for graduate school in the Psychology Department at Brown, where there were twelve graduate students and six faculty, four of whom were in the National Academy of Sciences. Around the time when I arrived, the characteristics of the small eye movements that occur during attempted steady fixation were well understood, but there was vigorous debate about the reasons for their occurrence and about their effects on vision. It is obvious that rotational eye movements cause the retina to shift under the retinal image. Our group and a group in England published papers within a month of each other showing that, when this movement of the retina with respect to the image of a scene is prevented, the scene disappears within a fraction of a second. The question debated then was whether or not the beginning of such disappearance was the trigger for the movements. My dissertation research showed that disappearance did not trigger movements. Instead, the eyes tend to drift away from the target and microsaccadic movements tend to correct the resulting fixation error.