Accession Number : AD0768344

Title :   A High Resolution Measurement of the Anisotropic Modulation Transfer Function of the Human Visual System.

Descriptive Note : Master's thesis,

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

Personal Author(s) : Guidry,Roland David

Report Date : JUN 1973

Pagination or Media Count : 147

Abstract : Apparatus and procedures were designed to measure differences in threshold perception of gratings for 12 grating orientations and 9 spatial frequencies (2.3 to 20.4 cycles per degree). Gratings were generated on an oscilloscope and rotated electronically at 15 degree increments using an image rotation device designed for this experiment. Fifteen subjects were tested using a multiple staircase paradigm: 12 staircases (one for each orientation) were run concurrently and randomly intermixed, with spatial frequency held constant. Results are presented as plots of contrast sensitivity versus grating orientation for each spatial frequency tested. Considerable variation occurred among the subjects, both in orientational preferences and experimental consistency. Three subjects were classified as meridional amblyopes, three as 'classics' (equal acuity for horizontal and vertical gratings but lower acuity for oblique gratings), and the remainder as having slight or inconsistent orientational preferences (from one spatial frequency to another). (Modified author abstract)

Descriptors :   (*VISUAL PERCEPTION, *SPACE PERCEPTION), VISION, PSYCHOPHYSICS, THRESHOLDS(PHYSIOLOGY), ANISOTROPY, THESES

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE