Engineering topics

Hettinger, Lawrence J.

Publications and source records attributed to Hettinger, Lawrence J..

4 records

NASA NTRS1993

Changes in the dark focus of accommodation associated with simulator sickness

The relationship between the dark focus of accommodation and simulator sickness, a form of motion sickness, was examined in three experiments. In Experiment 1, dark focus was measured in 18 college students in a laboratory setting before and after they viewed a projected motion scene depicting low altitude helicopter flight. In Experiments 2 and 3, dark focus was measured in pilots (N = 16 and 23, respectively) before and after they 'flew' in moving-base helicopter flight simulators with optical infinity CRT visual systems. The results showed that individuals who experienced simulator sickness had either an inward (myopic) change in dark focus (Experiments 1 and 3) or attenuated outward shifts in dark focus (Experiment 2) relative to participants who did not get sick. These results are consonant with the hypothesis that parasympathetic activity, which may be associated with simulator sickness, should result in changes in dark focus that are in a myopic direction. Night vision goggles, virtual environments, extended periods in microgravity, and heads-up displays all produce related visual symptomatology. Changes in dark focus may occur in these conditions, as well, and should be measured.

Fowlkes, Jennifer E.↗

NASA NTRS1991

Illusory self motion and simulator sickness

Presented here is a discussion of simulator sickness (with applications to motion sickness and space sickness) based on the notion of senses as perceptual systems, and the sensory conflict theory. Most forms of the sensory conflict theory unnecessarily propose the existence of a neural store. The neural store is thought to consist of a record of previous perceptual experiences against which currently experienced patterns of stimulation are compared. The authors seek to establish that in its most parsimonious form the sensory conflict theory does not require a construct such as the neural store. In its simpler form, the sensory conflict theory complements and extends Gibson's view of the senses as perceptual systems.

Hettinger, Lawrence J.↗

NASA NTRS1989

Summary of proceedings of the first meeting of the NASA Ames Simulator Sickness Steering Committee

A program of research to investigate simulator induced sickness has recently been initiated under the sponsorship of NASA Ames Research Center to coordinate efforts to investigate and eventually eliminate the problem of simulator sickness. As part of this program, a Simulator Sickness Steering Committee has been assembled, comprised of eighteen representatives from the Army, Air Force, Navy, NASA, NATO, academia, and industry. The proceedings of the first meeting of the NASA Ames Simulator Sickness Steering Committee are summarized and discussed.

Hettinger, Lawrence J.↗

NASA NTRS1989

Visually guided control of self motion

A workshop entitled 'Visually Guided Control of Movement' was held at NASA Ames Research Center on June 26 - July 14, 1989. The workshop brought together individuals with diverse backgrounds related to the areas of the visual perception and control of motion. During the workshop, participants designed and conducted experiments using NASA Ames flight simulation research facilities. These studies contrasted participants' alternative theoretical approaches to the visual control of self motion. Panel members, drawn from the workshop's participants, will discuss their approaches to the study of the control of self motion and will present interpretations of the outcomes of the workshop.

Hettinger, Lawrence J.↗