CORTICAL CONTROL OF EYE MOVEMENTS AND VISUAL THRESHOLD.
Abstract
Experimental investigations were conducted on the increase in the threshold for visual perception which occurs just prior to, and during eye movements. To measure the visual threshold in the vicinity of eye movement an apparatus was constructed having alternately burning lights. Some time after switching, a flash of short duration of controlled intensity was presented which fell in the vicinity of the subject's eye movement. Eye movements were measured by reflection of light from the surface of the eye. The reflection data is fed to a 'pattern recognizer' which records the onset of eye movement. The subject records whether or not he saw the flash. The threshold for perception as a function of eye movement was measured. The equipment could present one or two light flashes to the subject. Each light source had a diameter of 7 minutes of arc, with an angular separation between the two lights up to several degrees. It was found that the detection of one light flash would facilitate the detection of the other light flash. For example, if the probability of detecting either light, separately, was 0.3, the probability of detecting both together was 0.2, rather than 0.09. This facilitation experiment was then repeated with a resting eye, with the following results, which hold for both the light adapted and the dark adapted eye: 1. It is most likely a retinal effect, which affects both rods and cones equally. 2. Outside the area of summation the distance between the two flashes is of minor importance. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1965
- Accession Number
- AD0624790
Entities
People
- Maarten A. Bouman