EFFECTS OF NITROUS OXIDE ON SUBJECTIVE AND OBJECTIVE VARIABLES

Effects of nitrous oxide in different subanaesthetic concentrations were studied in twelve subjects. Subjective scales of intoxication and of eight other mood variables were obtained by the method of magnitude estimation. Objective performance was examined by tests on memory and arithmetic. For most variables the dose-response curves obtained showed progressively larger effects with increasing dose-levels. At concentrations below 20 per cent the changes were, on the whole, very slight. The results are compared with similar data from an alcohol experiment.     

PSYCHOPHYSIOLOGICAL REACTIONS TO INFUSIONS OF A MIXTURE OF ADRENALINE AND NORADRENALINE

F rankenhaeuser , M. & J ärpe , G. Psychophysiological reactions to infusions of a mixture of adrenaline and noradrenaline. Scand. J. Psychol ., 1962, 3 , 21–29.—Psychophysiological reactions to a mixture of adrenaline and noradrenaline (average dose 6.99 + 6.99 μg/min.) given as a continuous intravenous drip for periods of about 40 min. were studied in 11 subjects. Control data were obtained from placebo infusions. The catecholamine infusions produced marked subjective and overt symptoms as well as changes in heart rate and blood pressure. These reactions were—on the whole—similar to those produced by infusions of adrenaline only. Time experience was also affected by the catecholamines in that more was retained of the previously perceived time intervals.     

INTERINDIVIDUAL DIFFERENCES IN CATECHOLAMINE EXCRETION DURING STRESS

Measurements of adrenaline and noradrenaline excretion during inactivity and stress, and ratings of 22 personality variables were obtained for 110 subjects. Six factors were extracted by a factor analysis. Two of the factors were associated with personality variables, three primarily with catecholamines, and one with both types of variables. The 'mixed.' factor was tentatively interpreted as indicating that individuals with depressive tendencies respond to stressors with a relatively smaller rise in adrenaline excretion. This finding is in line with current theories concerning the role of catecholamines in affective psychoses.     

THE SUSCEPTIBILITY OF INTELLECTUAL FUNCTIONS TO A DEPRESSANT DRUG

F rankenhaeuser , M., and B eckman , M. The susceptibility of intellectual functions to a depressant drug. Scand. J. Psychol ., 1961, 2 , 93–99.—The performance of 32 subjects in tests on four intellectual factors (verbal, numerical, inductive and spatial) during the inhalation of nitrous oxide (30 per cent N₂O and 70 per cent O₂) and a control mixture (30 per cent N₂ and 70 per cent O₂) were compared . The drug caused a highly significant deterioration in the performance of all four tests. Both speed and accuracy of performance were impaired. The problem of a possible differential susceptibility to the drug of the various intellectual functions wag attacked by a statistical analysis of the differences between the tests with regard to changes in performance during drug inhalation. No reliable differences in extent of impairment between the four tests could be demonstrated.     

The influence of cognitive set on performance and arousal under different noise loads

Three groups of 12 subjects each performed a mental arithmetic task while exposed to continuous white noise in two experimental sessions. In Session I, each group was exposed to a different noise level [56, 72.5, or 85dB(A)], whereas in Session II all had the medium [72.5 dB(A)] intensity. Arithmetic performance deteriorated with increasing noise intensity in Session I, and in Session II each group retained its position relative to the other two groups. Thus, the higher the noise intensity in the first session, the poorer the performance in the second session. These results suggest that the motivation and energy mobilized in Session II were determined by the cognitive set adopted to meet the demands of Session I. Arousal level, as measured by adrenaline excretion and heart rate, was higher during both experimental sessions than in a control session. The rise in adrenaline output was of the same magnitude regardless of the intensity of the noise, which indicates that the subjects adjusted to the increase in total load by slowing down their performance rather than by raising their energy mobilization. Heart rate rose in response to changes in noise level in Session II relative to Session I, regardless of the direction of the change.     

CATECHOLAMINE EXCRETION IN YOUNG CHILDREN AND THEIR PARENTS AS RELATED TO BEHAVIOR

L ambert , W. W., J ohansson , G., F rankenhaeuser , M. & K lackenberg -L arsson , I. Catecholamine excretion in young children and their parents as related to behavior. Scand. J. Psychol ., 1969, 10, 306–318. — Catecholamine excretion in 100 children and their parents was examined in relation to the children's behavior and to data on the parents' disciplinary procedures: ( a ) children's adrenaline excretion was positively correlated with their intellectual level, ( b ) their noradrenaline excretion was positively correlated with that of their mothers, as well as with both parents' age at the birth of the child, ( c ) mothers' adrenaline excretion was positively correlated with the frequency at which the fathers punished their children by smacking, and ( d ) fathers' noradrenaline excretion was negatively correlated with their own as well as with their wives' frequency of smacking their children.     

OBJECTIVE AND SUBJECTIVE PERFORMANCE AS INFLUENCED BY DRUG-INDUCED VARIATIONS IN ACTIVATION LEVEL

Performance was measured by seven sensorimotor and perceptual tests given to 30 students in six successive trials, spread over five hours, before and after the intake of either 15 mg dexamphetamine, zoo mg Pentobarbitone, or a placebo. Subjective performance, level of aspiration, wakefulness, and mood were measured by a scaling method. A close agreement was found between the amount of objective and subjective improvement following dexamphetamine, whereas the objective impairment induced by Pentobarbitone was not reflected in the subjective measures. These results were examined in relation to the other indices of activation.