Daisy Schalling

Testosterone, Aggression, Physical, and Personality Dimensions in Normal Adolescent Males

&NA; Fifty‐eight normal adolescent Swedish boys, aged 16, provided two sets of blood samples for plasma testosterone assays as well as data on a number of personality inventories and rating scales assessing aggression, inpulsiveness, lack of frustration tolerance, extraversion, and anxiety. Physical variables such as pubertal stage, height, weight, chest circumference, and physical strength were measured. There was a significant association (r = 0.44) between plasma testosterone levels and self‐reports of physical and verbal aggression, mainly reflecting responsiveness to provocation and threat. Lack of frustration tolerance was also related to testosterone levels. About 40% of the variance in perfectly reliable testosterone measurements could be predicted from equally reliable Physical + Verbal Aggression and Lack of Frustration Tolerance scales. Pubertal stage was correlated with testosterone (r = 0.44), but the above‐mentioned relationships could not be accounted for by pubertal stage as a third common variable. Previous hypotheses relating testosterone to strong body build and antisocial behavior, respectively, received only weak or no support.

Circulating testosterone levels and aggression in adolescent males: a causal analysis.

&NA; Empirical analyses conducted within a causal‐analytic framework (path analysis) on a sample of normal adolescent human males suggested that circulating levels of testosterone in the blood had a direct causal influence on provoked aggressive behavior (self‐reports): A high level of testosterone led to an increased readiness to respond vigorously and assertively to provocations and threats. Testosterone also had an indirect and weaker affect on another aggression dimension: High levels of testosterone made the boys more impatient and irritable, which in turn increased their propensity to engage in aggressive‐destructive behavior. Two somewhat parallel dimensions of behavior, intermale and irritable aggression, have been identified in animal research to be under testosterone control.

Low platelet monoamine oxidase activity in cigarette smokers.

Abstract The activity of platelet monoamine oxidase was found to be significantly lower in normal female subjects who smoked at least 5 cigarettes per day than in non-smokers. The platelet MAO activity of individuals who had given up smoking was not significantly different from the activity for non-smokers. The difference in activities between smokers and non-smokers, due entirely to a Vmax rather than a Km change, was not due to a direct effect of nicotine upon the platelet MAO. In addition, platelet-poor plasma from smokers activated platelet MAO in an identical manner to that from non-smokers. The significance of these results are discussed in terms of personality characteristics such as impulsivity and sensation seeking, that may be related to both smoking and to low MAO activity.

Smooth pursuit eye tracking, neuropsychological test performance, and computed tomography in schizophrenia

Smooth pursuit eye movements (SPEM) were measured in 18 patients who met Research Diagnostic Criteria for schizophrenia. Some degree of SPEM impairment was present in most patients. Deviant eye tracking was not related to ratings of severity of illness, but was related to recurrent episodes of hospitalization, antipsychotic medication, and lower ratings in anxiety and delusions. Worse SPEM tended to be associated with larger lateral ventricles as assessed on computed tomography. Three patients with reversed occipital asymmetry had more deviant eye tracking than the remaining patients. Eye movement impairment was related to worse performance in Finger Tapping and in the Trail-Making Test, and to fewer perceived alternations of a Necker cube, suggesting that frontoparietal disturbances are related to poor pursuit eye tracking in schizophrenia.

Urinary catecholamines, stress, and psychopathy: a study of arrested men awaiting trial.

&NA; The urinary excretion of adrenaline (A) and noradrenaline (NA) in a group of 24 arrested men was measured in three experimental sessions: 2 weeks, 1 week, and immediately before trial. The first session was assumed to represent a moderate laboratory stress due to the novelty of the situation and the last session a real life stress, associated with anticipation of appearing in court. Both are superimposed on the sustained real life stress of being in jail. There was no significant increase in A or NA in the last, presumedly the most stressful session. However, when personality measures were taken into account, there were significant and consistent differences in the pattern of A and NA excretion over the sessions between subgroups of subjects. Subjects high in psychopathy did not react with an increase in either A or NA in the last, presumedly the most stressful session. They also had conspicuously lower NA excretion, as compared to subjects low in psychopathy and relative to their own A excretion. Subjects low in psychopathy showed a reversed pattern.

Exploring the connections between platelet monoamine oxidase activity and behavior: relationships with performance in neuropsychological tasks.

Platelet MAO activity has been found to have behavioral (psychiatric and personality) correlates. The purpose of the present study was to explore the nature of the connections between platelet MAO activity and behavior by analyzing performance in neuropsychological tasks in relation to platelet MAO activity, measured in 37 male subjects. The following neuropsychological tests were given: a finger tapping and alternation test, a reaction time test, a perceptual maze test, a perspective fluctuation task (the Necker cube), and a lexical decision task. The reaction time tasks comprised a motor disinhibition task, in which auditory stimuli given simultaneously with light stimuli were signals for response inhibition. Significant relationships were obtained between low MAO activity and short response times and small variations in response times to left-sided visual stimuli, suggesting a readiness for higher right hemisphere activation in low MAO subjects, and between low platelet MAO activity and many perspective reversals, in line with expectations. Furthermore, high MAO subjects had equal tapping speed for both hands, which has been found in schizophrenic patients. Of special interest in the present results is the strong negative relationship obtained between platelet MAO activity and number of failed inhibitions in the motor disinhibition task, which in a multiple regression analysis highly significantly contributed to the prediction of platelet MAO activity. This finding is in line with the poor passive avoidance performance associated with serotonergic deficiency and syndromes of disinhibition, and thus supports the assumption that platelet MAO activity may be considered as a genetic marker for some properties of the central serotonergic system.

COGNITIVE SEX DIFFERENCES: SPEED AND PROBLEM-SOLVING STRATEGIES ON COMPUTERIZED NEUROPSYCHOLOGICAL TASKS

Skill, strategy, and laterality measures obtained through computerized neuropsychological tasks, a reaction time (RT) test, and a visuospatial problem-solving test, the Perceptual Maze Test, were analyzed in relation to sex and handedness of 56 high-school students. Boys were significantly faster than girls on most RT subtasks (including a response-inhibition task) and made more two-choice RT response errors for right-sided stimuli, which may be interpreted as resulting from a less cautious strategy. In maze performance, boys were superior to girls. An analysis of separate phases of the maze-solution process suggested that boys preferentially used an impulsive-global strategy. Girls, using a more reflective-sequential task-solving strategy, were significantly slower, without hitting more targets. Compared to all other groups, left-handed girls (strongly left-handed) had lower performance on maze tasks with no target information, particularly in left-sided solution pathways. Results were interpreted as reflecting differences in hemispheric competence and activation patterns between the sexes. Signs of a less differentiated lateralization and slight dysfunction of visuospatial skills in the left-handed girls were discussed.

Impulsivity and speed and errors in a reaction time task: A contribution to the construct validity of the concept of impulsivity

Abstract Acting on the spur of the moment without considering the effects is one of the core attributes of the extraversion-impulsivity concept. Performance in a choice-reaction time task may reflect this tendency. Reaction time and number of errors were studied in a group of 55 boys (15–17 years). Extraversion-impulsivity, anxiety proneness and some other personality characteristics were measured by inventory scales. As hypothesized more impulsive subjects had shorter reaction times and made more errors than less impulsive. This relationship was rather stable over a period of one month. Subjects with higher scores in the Psychoticism scale of the Eysenck Personality Questionnaire tended to make more errors. A considerable amount (36%) of the variance in the number of errors variable could be predicted from the three personality variables Impulsiveness, Muscular Tension and Psychoticism.

Exploring the connections between platelet monoamine oxidase activity and behavior. II. Impulsive personality without neuropsychological signs of disinhibition in air force pilot recruits

Platelet monoamine oxidase (MAO) activity and serum levels of the adrenal androgen metabolite dehydroepiandrosterone sulfate (DHAS) were measured in 18 male air force pilot recruits and 19 randomly selected male conscripts. Personality scales from three inventories were given, and computerized neuropsychological tests were performed: finger tapping and alternation, reaction time, perceptual maze, perspective fluctuation and lexical decision. The pilot recruits had higher scores in sensation-seeking-related scales suggesting disinhibited behavior in the social sphere, interest in sports and activities involving some danger, and a need for change. They also had higher scores on an impulsivity scale which comprises sensation-seeking content. In the neuropsychological tasks, the pilot recruits were faster in finger-tapping alternation and performed more efficiently in the perceptual-maze test than the conscripts. In a linear discriminant analysis, neuropsychological-task performance discriminated significantly between the pilot and conscript groups. In the biochemical measures, the pilot recruits had higher DHAS levels but similar MAO activity levels compared to the conscripts, which is in contrast to what has been found in other sensation-seeking groups in comparison to controls. This result is in accordance with the normal scores in one of the impulsivity scales in the pilot recruits, and with the absence of signs of disinhibition in neuropsychological tasks. It is proposed that only some aspects of the impulsivity concept might be critical for the association with low MAO activity.

Smoking, pain tolerance, and physiological activation.

The effects of tobacco smoking and β-blockade on psychophysiological measures, i.e., heart rate (HR), blood pressure (BP), skin conductance (SC), and sensitivity to electrical pain stimulation was studied in a group of 33 male moderate smokers. Using a method of limits threshold determination technique, measures of pain threshold (PT), and tolerance level (TL) were obtained. The results were analyzed in relation to smoking habits, personality measures, and subjective effects. There was no significant effect of smoking on pain sensitivity. Smoking caused a physiological activation as indicated by an increase in HR and systolic BP. β-Blockade counteracted the smoking-induced increase in HR and systolic BP, but did not influence PT or TL. Subjective effects of smoking were not affected by β-blockade. The findings suggest that physiological activation is not related to effects of smoking on pain.