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Biomedical subjects

J A Kinney

Publications and source records attributed to J A Kinney.

12 recordsLinked to original sources
PubMed1979

Effects of aspirin and dimenhydrinate (Dramamine) on visual processes.

1. The effect of three doses of either aspirin (1280 mg each) or dimenhydrinate (Dramamine) (100 mg each) in an 8 h period on visual processes was investigated double-blind on sixteen volunteer subjects. 2. Tests included night-vision, colour-discrimination, stereoacuity and stereopsis, reaction-time, pupil size, eye-movements, visual evoked cortical potentials, electroencephalographs, a dial-reading task, and a test of texture discrimination. 3. Both drugs affected colour discrimination, and dimenhydrinate degraded night-vision, reaction-time, and stereopsis. 4. The effect of aspirin was minor, but the impairments produced by dimenhydrinate appear to be of practical importance.

Adult↗
PubMed1979

The ability of color defectives to judge signal lights at sea.

Measures were made of the ability of color-defective men to judge correctly the colors of navigation lights (red, green, or white) presented to them at night under realistic sea conditions. Eighty-one color-defective men were employed; they were categorized as to type and degree of defect using a battery of five color-vision tests. While the average performance of the color-defective men was considerably poorer than that of 24 color normals, there were large individual differences within each category of defect. Attempts to account for these differences in performance by variations in acuity, intelligence, and motivation failed. The extent to which the data can be accounted for by modern color-vision theory is discussed.

Color Vision Defects↗
PubMed1979

Vision of submariners.

A variety of vision tests have been administered to submariners over the years. The results show that the average submariner, though maintaining a normal, healthy visual system, has distant acuity somewhat below normal and manifests more myopia, esophoria, and less accommodative power than men of comparable age, as documented in the literature. The reasons for these changes are unknown but probably involve confinement; whether confinement peculiar to the submarine of the "confinement" of urban living is the more important for these changes is discussed.

Accommodation, Ocular↗
PubMed1978

Visual evoked cortical potentials in men during compression and saturation in He-O2 equivalent to 400, 800, 1200 and 1600 feet of sea water.

Visual evoked cortical potentials and related EEG activity were recorded from subjects during rapid compression and exposure to pressures of 400, 800, 1200 and 1600 fsw. In one phase, subjects made repeated excursions to 1200 fsw from a base at 800 fsw; in the second phase, the saturated base was 1200 fsw with excursions to 1600 fsw. The results included: (1) For the visual evoked potentials, sizeable and significant decreases in amplitude and increases in latency of the response with depth; (2) Changes in the visual evoked potentials which varied systematically with depth but not with related changes in compression rate or decompression. The changes were small but consistent alterations of normal responses to visual stimulation; and (3) Theta activity in discrete EEG recordings increased progressively with depth. With all subjects showed increases in theta activity the pattern of increase varied individually.

Alpha Rhythm↗
PubMed1977

Transient visually evoked potential.

A light delivered to the human eye will instigate changes in electrical potentials recorded over the visual cortex that last for some finite time, at least several hundred milliseconds. If the rate of stimulation is sufficiently low, the response is completed before the next visual stimulus arrives; the cortical potential is then called a transient evoked response. This review of the transient evoked potential describes the techniques by which the response is obtained, the problems inherent in its use, and procedures by which these difficulties can be overcome or minimized. A summary of the research results from the field enumerates those findings which have been well established and replicated by many investigators, those that are more controversial or as yet inconclusive, and the many practical applications of the technique for science and medicine. Finally, the needs for an underlying physiological theory and for future research are discussed.

Color Vision Defects↗
PubMed1977

The use of fluorescein angiography to study oxygen toxicity.

This study was designed to test whether oxygen toxicity results in retinal damage that could be documented by the technique of fluorescein angiography. Three squirrel monkeys lived in 100% oxygen environments for periods ranging from 50 to 117 hours. Two of the monkeys incurred damage as evidenced by early multifocal leakage and subsequent accumulation of dye in the retina. All monkeys survived the exposures and were followed for several weeks thereafter. The pathology appeared to be reversible since later angiograms were either normal, or approaching normality, when the animals were sacrificed. Subsequent histopathologic examination revealed no abnormalities.

Animals↗
PubMed1977

Visual evoked responses and EEG's of 16 divers breathing air at 7 ATA.

This study is an assessment of individual differences in electrophysiological response under diving conditions normally conducive to nitrogen narcosis. A group of 16 men made two dives each to approximately 200 ft in a pressure chamber while breathing air. The visual evoked response of the men at depth revealed several decrements; in the response to a slow rate of stimulation, there was a highly significant reduction in a component around 160 ms, and in the response to a rapid rate of stimulation, marked losses in amplitude and increases in variability were found. The latter changes were related to diving experience while the former were not. No significant changes were found in alpha or theta activity in the EEG.

Adult↗
PubMed1977

Visual evoked responses, EEG's and reaction time during a normoxic saturation dive, NISAT I.

Three Navy divers were exposed to a normoxic breathing mixture at 7.0 ATA for seven consecutive days. Visual evoked responses (VER's), electroencephalograms (EEG's) and simple reaction time (RT) were measured. Previously reported amplitude decreases in a VER to a flash rate of 1 Hz (VER 1) and to a flash rate of 16 Hz (VER 16) were again found during this dive. The variability of the VER 16 and the latency of the VER 1 also increased during the saturation period. In the EEG analysis, changes in the amplitude of both alpha and theta were found, as were decreases in alpha frequency. The RT task showed a marked elevation of response time at the beginning of the dive period which gradually returned to predive levels. Latency of the VER 160-180 ms component was highly correlated with the changes in RT. The results are discussed in terms of information processing and cerebral dysfunction.

Atmospheric Pressure↗
PubMed1975

Vision in the water without a facemask.

Distance and size estimates and stereoacuity judgments were made in water by divers, both with and without facemasks. Without the mask, only stereoacuity was markedly degraded. Distance estimates were slightly more accurate, despite a great decrease in the range of visibility. Size estimates were slightly too small. Divers with refractive errors did not appear to be more handicapped than those with normal vision.

Distance Perception↗