Accession Number : ADA189557

Title :   Retinotopic Mapping of the Human Visual System with Magnetoencephalography.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Dowler, Michael G

PDF Url : ADA189557

Report Date : Dec 1987

Pagination or Media Count : 72

Abstract : A retinotopic mapping was verified using magnetoencephalography as the means to observe brain activity in one human subject. The stimulus consisted of 12 sectors of a hemicircle, 6 foveal and 6 peripheral out to about 17 degrees visual field angle. The sectors flashed individually for 63 milliseconds with an inter-stimulus-interval between .8 and 1.8 seconds. The recording computer was syncronized to the stimulus and recorded for .5 seconds after onset of stimulus. Thirty averages were taken for each stimulus section, for each of about 45 grid points on the scalp. The sectors were localized to distinct points in the primary visual cortex (area 17). The results did not verify the cruciform model of retinotopic mapping nor the theory that more visually eccentric stimuli produce deeper responses. The data seem to suggest and different type of mapping for foveal stimuli than peripheral, but this could also be due to the fold structure of the primary visual cortex. Keywords: Artificial intelligence, Depth perception, Image processing, Pattern recognition.

Descriptors :   *ARTIFICIAL INTELLIGENCE, *IMAGE PROCESSING, *MAGNETOENCEPHALOGRAMS, *RETINA, BRAIN, COMPUTERS, CRUCIFORM CONFIGURATIONS, FOVEA, HEAD(ANATOMY), HUMANS, MAPPING, MODELS, PATTERN RECOGNITION, RECORDING SYSTEMS, SKIN(ANATOMY), SPACE PERCEPTION, STIMULI, VISION, VISUAL CORTEX, THESES, COMPUTER APPLICATIONS

Subject Categories : Anatomy and Physiology
      Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE