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Biomedical subjects

L R Young

Publications and source records attributed to L R Young.

At least 73 records · Page 4Linked to original sources
PubMed1976

Perception of static orientation in a constant gravitoinertial environment.

The illusions associated with the perception of static tilt in various specific force environments have been reviewed and then classified in such a way that a simple perceptual model could be developed to account for the experimental data. The fundamental conclusion to be drawn from this model is that these illusions can be accounted for by a simple non-linear transformation of the information primarily from the saccule.

Aerospace Medicine↗
PubMed1976

The etiology of ski injuries: an eight year study of the skier and his equipment.

Detailed ski injury statistics have been maintained at Waterville Valley, New Hampshire, since the opening of the area as a major ski resort in 1966. These statistics were examined to uncover some of the major contributory factors involved in ski accidents. The characteristics that set this study aside from other such reports are the inclusion of both an adequately sized normal control population and the longitudinal collection of comparable data from a relatively stable skiing population over an eight year period, to reveal trends in the number and type of accidents.

Age Factors↗
PubMed1975

Perceived visual motion as effective stimulus to pursuit eye movement system.

Human eye tracking of a foveal afterimage during angular head oscillation in the dark produced smooth eye movements exceeding those for normal vestibular nystagmus, and a reduction in the frequency of the fast phase component of nystagmus eye movements. These results may support a closed loop extension of the corollary discharge theory, with oculomotor commands based on perceived object velocity.

Attention↗
PubMed1975

Perception of linear horizontal self-motion induced by peripheral vision (linearvection) basic characteristics and visual-vestibular interactions.

The basic characteristics of the sensation of linear horizontal motion have been studied. Objective linear motion was induced by means of a moving cart. Visually induced linear motion perception (linearvection) was obtained by projection of moving images at the periphery of the visual field. Image velocity and luminance thresholds for the appearance of linearvection have been measured and are in the range of those for image motion detection (without sensation of self motion) by the visual system. Latencies of onset are around 1 sec and short term adaptation has been shown. The dynamic range of the visual analyser as judged by frequency analysis is lower than for the vestibular analyser. Conflicting situations in which visual cues contradict vestibular and other proprioceptive cues show, in the case of linearvection a dominance of vision which supports the idea of an essential although not independent role of vision in self motion perception.

Adaptation, Psychological↗
PubMed1975

Ernst Mach on the vestibular organ 100 years ago.

Ernst Mach (1838-1916) performed pioneering research on vestibular function 100 years ago. His experiments were mainly psychophysical and included measurements of threshold and study of the vestibular-visual interaction. Contrary to general belief, he concluded that the adequate stimulus for the semicircular canals must be pressure. He presented evidence specifically against the sustained endolymph flow theory of Breuer (1874) and Crum Brown (1874), with which he is frequently associated. Excerpts from his publications are given and their relevance to current research is discussed.

Germany↗
PubMed1975

Influence of head orientation on visually induced pitch and roll sensation.

Observers viewing rotating scenes in their periphery frequently experience self-motion in the opposite direction. A full field (360 degrees) flight simulator projection system was used to investigate the sensations resulting from pitch, roll, and yaw stimuli at various head orientations. Steady yaw rate (circularvection) and development of a constant roll tilt angle, for the head erect and constant velocity yaw and roll stimuli, confirmed previous reports. Pitch stimuli also were found to produce a sensation of tilting to a steady pitch angle, which was much stronger for pitch forward than backward. Pitch and roll effects were strongly dependent on head position, increasing for the head rolled 90 degrees to the side or inverted, and decreasing for the head pitched 25 degrees forward. These results support a hypothesis that visually induced tilt is limited by conflict with otolith information.

Aerospace Medicine↗
PubMed1972

Moving visual scenes influence the apparent direction of gravity.

When an observer views a wide-angled display rotating around his line of sight, he both feels his body tilted and sees a vertical straight edge tilted opposite to the moving stimulus. Displacement of the perceived vertical increases with stimulus speed to reach a maximum (averaging 15 degrees) at 30 degrees per second.

Humans↗