PubMed Health⌕ Search

Biomedical subjects

R D Savage

Publications and source records attributed to R D Savage.

At least 19 recordsLinked to original sources
PubMed1978

Intellectual impairment in chronic renal failure.

In a dialysis centre with a high tap water aluminium content and a known high incidence of dialysis encephalopathy, 29 patients undertaking regular home dialysis, without clinical evidence of encephalopathy, were studied with a battery of psychological tests that have proved useful in detecting early organic intellectual deterioration in other conditions. Full-scale intelligence quotient, as measured by the Wechsler Adult Intelligence Scale, did not differ significantly from that of the normal population, but the patients showed significant deficiencies in three tests of performance--namely, digit symbol, block design, and picture arrangement. The ability to acquire new information in relation to performance was impaired and the abnormality increased with time on dialysis. Such tests should be useful in early detection of dialysis dementia at a reversible stage.

Adolescent↗
PubMed1972

A method for measuring human behavioural and physiological responses at different stress levels in a driving simulator.

1. A method is described by which a car simulator can be used to measure, simultaneously, motor-perceptual performance and physiological responses of human subjects under different levels of task difficulty or stress.2. Motor-perceptual performance was measured in terms of reaction times taken by subjects to carry out steering, braking and operation of traffic indicators in the simulator. Subjects were instructed to carry out the different driving manoeuvres by means of a command panel containing five coloured lights. Three levels of task difficulty or stress were devised. In level 1 only the light signals were used. In level 2 the driving simulator film was shown and all of the light signals reinforced the movements of the car in the film. Level 3 was similar to level 2, with the exception that whilst some of the light signals reinforced the movements of the car, others deliberately conflicted with it.3. Physiological responses measured were heart rate, blood pressure, respiration and calf blood flow. Personality was also measured by means of the Cattell 16 personality factor questionnaire.4. Analysis of variance of the performance of 15 subjects showed significant variation between the three task levels (P=<0.001 for steering reaction times; P=<0.01 for brake and indicator reaction times). In all cases the reaction times were longest for level 3, indicating that this was the most difficult task. The number of anticipated responses to steering, braking and traffic indicator signals was highest in level 2, while the number of corrections to steering and braking responses was lowest in level 2. None of these differences was statistically significant.5. Of the physiological variables, the heart rate showed a progressive increase from task levels 1 to 3 but only those between levels 1 and 3 were statistically significant (P<0.05).6. The results are discussed in relation to the validity of the method. It is concluded that by means of this method it is possible to produce controlled and reproducible degrees of stress and under conditions which are also suitable for the investigation of pharmacological agents upon it.

Adult↗
PubMed1972

The effects of cigarette smoking on the response to stress in a driving simulator.

1. Some behavioural and physiological responses of cigarette smokers and non-smokers exposed to varying degrees of stress in a driving simulator were compared.2. When the smokers were smoking a cigarette, some of their reaction times to light signals differed significantly from those of non-smokers, some being longer and some shorter. These differences disappeared when the smokers were not smoking.3. Of the physiological measurements, only heart rate differed significantly between smokers and non-smokers, being higher at all levels of stress in the smokers. There were no significant differences in blood pressure, calf blood flow and respiration rate between smokers and non-smokers.4. The results of the Cattell Sixteen Personality Factor Questionnaire showed that the smokers were significantly more extroverted and self-reliant than the non-smokers.5. The results are discussed in relation to the pharmacology of cigarette smoking. It is concluded that the differences in reaction times and heart rates between smokers and non-smokers were a consequence of cigarette smoking.

Adolescent↗