Accession Number : ADA187703

Title :   Laser Flash Effects on Chromatic Discrimination in Monkeys.

Descriptive Note : Final rept. Apr 86-Jun 87,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX

Personal Author(s) : Schmeisser, Elmar T

PDF Url : ADA187703

Report Date : Oct 1987

Pagination or Media Count : 26

Abstract : Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak energy criterion (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown that, on the measures of acuity, sensitivity, tracking, and contrast detection, the animals recover to baseline if the exposure has remained below the MPE. The one measure that has not been investigated is color discrimination. The major conclusions from this investigation are: (a) red and green colored laser flashes shift the color balance transiently in the visual system, and yellow flashes do so to a lesser extent; thus targets may change both hue and brightness after an observer receives colored flashes; and (b) Q-switched lasers, at non-lesioning levels, when equated for time-averaged perceptual brightness, have comparable effects to flashes with longer time courses.

Descriptors :   *FLASHES, *VISION, *LASER HAZARDS, *LASER DAMAGE, BALANCE, BRIGHTNESS, CAMOUFLAGE, CHROMATICITY, COLORS, CONTRAST, DAMAGE ASSESSMENT, DETECTION, DISCRIMINATION, DOSAGE, ENERGY, IRRADIATION, LASER BEAMS, LASERS, LIGHT PULSES, LOW ENERGY, LUMINANCE, MASKING, MOTION, OBSERVERS, PEAK VALUES, Q SWITCHING, RADIATION EFFECTS, SENSITIVITY, SHORT PULSES, SOURCES, TARGETS, TERRAIN, TRACKING, VISIBLE SPECTRA, YELLOW(COLOR), MONKEYS, IRRADIATION, EXPOSURE(PHYSIOLOGY), TARGET DISCRIMINATION, VISUAL ACUITY, VISUAL PERCEPTION

Subject Categories : Anatomy and Physiology
      Stress Physiology
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE