Accession Number : ADA189757

Title :   A Comparison of Visual Evoked Potential and Behavioral Measures of Flashblindness in Humans.

Descriptive Note : Final rept. Sep 85-Oct 86,

Corporate Author : KRUG INTERNATIONAL SAN ANTONIO TX TECHNOLOGY SERVICES DIV

Personal Author(s) : Previc, Fred H ; Allen, Ralph G

PDF Url : ADA189757

Report Date : Sep 1987

Pagination or Media Count : 17

Abstract : A comparison between visual evoked potential (VEP) and behavioral measures of flashblindness following exposure to intense but eyesafe xenon flashes was performed. The purpose was to further validate the animal model of laser flashblindness based on VEP recordings in anesthetized rhesus monkeys. Monopolar VEPs were recorded from the posterior scalp of six human subjects in response to square-wave gratings of three differential spatial frequencies. The VEPs were recorded prior and subsequent to the presentation of a 125-ms, 7, 3 log td-s xenon flash. The results showed that the moment of initial post-flash visibility of the grating as assessed by the VEP's recovery above its baseline was highly comparable to that measured behaviorally. This comparison was demonstrated more clearly in the group data than in data obtained from individual subjects, suggesting that the predictive ability of the VEP depends in part on its signal-to-noise ratio. In general, the the assumptions underlying the animal flashblindness model are largely supported by the high correlations between predicted and obtained recovery estimates in this study and previous monkey studies.

Descriptors :   *FLASHBLINDNESS, ANIMALS, BEHAVIOR, CORRELATION, ESTIMATES, FREQUENCY, GRATINGS(SPECTRA), HEAD(ANATOMY), LASERS, MODELS, MONKEYS, RECOVERY, RESPONSE, RHESUS MONKEYS, SIGNAL TO NOISE RATIO, SKIN(ANATOMY), SPATIAL DISTRIBUTION, SQUARE WAVES, XENON LASERS, EXPOSURE(PHYSIOLOGY)

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE