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Biomedical subjects

W O Dwyer

Publications and source records attributed to W O Dwyer.

12 recordsLinked to original sources
PubMed1995

Sleep compression and sleep education for older insomniacs: self-help versus therapist guidance.

A treatment package consisting of a bed-time restriction strategy and education was administered to 50 insomniacs and 50 noninsomniacs 60 years or older. Half of the insomniacs and noninsomniacs received treatment through a self-help video only, whereas the remaining treated participants received therapist guidance to supplement the video. A waiting-list control group of 25 senior insomniacs was also included. Sleep knowledge was equivalent for senior insomniacs and noninsomniacs. The self-help insomniac group exhibited improvement on multiple sleep variables, but the addition of therapist guidance appeared to enhance treatment outcome for sleep latency, wake time after sleep onset, and sleep satisfaction. Control participants also improved across time but were generally outperformed by treated insomniacs.

Aged↗
PubMed1979

Delta 9-tetrahydrocannabinol: elevation of absolute visual thresholds of rabbits.

The effect of Delta 9-tetrahydrocannabinol (THC) on the ability of rabbits to detect a minimal light stimulus (absolute visual threshold) was examined using the method of limits with an aversive classical conditioning paradigm. Both of two dosage levels of THC, similar to an amount ingested by a human from a single cigarette, significantly elevated the absolute visual threshold of all animals. Normal baseline thresholds, however, returned with 24 hours.

Animals↗
PubMed1977

Peripheral area-intensity interaction in scotopic visual reaction time.

Two observers performed simple reaction-time responses to peripheral stimuli of varying intensity (-2.5 to +1.0 log td) and angular subtense (10 to 210 min). The area-intensity combinations that produced each of three scotopic reaction-time criteria were calculated. Analysis of these combinations showed that the area-intensity reciprocity could not be predicted by traditional theories of spatial summation. Like earlier findings for peripheral photopic reaction-time criteria, the results indicated that for small stimulus sizes, area has a greater effect than intensity in determining the scotopic reaction-time responses.

Dark Adaptation↗
PubMed1976

Validity of the laser refraction technique for meridional measurement.

This study assessed the validity of the laser refraction technique for determining the refractive status of a given meridian of the eye. A subjective-to-BVA finding was taken on a total of 75 eyes, and the laser technique was then used to refract each of the 2 principal meridians that had been located by the subjective procedure. Correlations between laser and nonlaser findings indicated that the laser technique is a valid method for meridional refraction. Differential findings for against-the-rule astigmatism are also discussed.

Female↗
PubMed1975

Racial differences in color vision: do they exist?

The present experiment investigated the possibility that variation in fundus pigmentation among individuals may be related to differential color sensitivity. Fifty black and white observers representing a wide range of skin (and fundus) pigmentation made direct heterochromatic brightness matches for a white standard field against each of five chromatic comparison fields. Results indicated that pigment (i.e., racial) differences in color vision do not exist, as measured by the two psychophysical methods used. The data showed that the heterochromatic matches were less reliable for the more saturated colors, violet and red, and also that the psychophysical methods used to obtain the matching data differentially influenced the results for the more saturated colors.

Black People↗