Accession Number : AD0694007

Title :   DIRECTIONAL DIFFERENCES IN VISUAL ACUITY DURING VERTICAL NYSTAGMUS.

Descriptive Note : Joint rept.,

Corporate Author : NAVAL AEROSPACE MEDICAL INST PENSACOLA FLA

Personal Author(s) : Hixson,W. Carroll ; Niven,Jorma I.

Report Date : 16 JUL 1969

Pagination or Media Count : 13

Abstract : Twenty naval aviator candidates were exposed to four ramp velocity test profiles generated by the Human Disorientation Device. The head orientation was such that the y (left-right) axis was on the Earth-vertical rotational center of the device, with the resulting alpha y pitch stimulation eliciting vertical nystagmus which was recorded on all four profiles. During two of the profiles, the subjects were required to observe a visual target consisting of a vertically aligned series of dots and to report the duration of the period where dot fusion or target blur occurred as a result of the vertical nystagmus. It was found that during pitch forward angular acceleration resulting in nystagmus with a slow component upward, the loss of visual acuity was of a significantly longer duration than that present during stimulation in the opposite direction. Directional differences in the vertical nystagmus response were also observed. (Author)

Descriptors :   (*VISUAL ACUITY, *NYSTAGMUS), VESTIBULAR APPARATUS, ACCELERATION, ROTATION, STIMULATION(PHYSIOLOGY), RESPONSE(BIOLOGY)

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE