Interactive effects of noise with illumination and age on activity of rats

Locomotor activity of male, albino rats (25, 90, and 200 days old at the start of the experiment) was measured in conditions of light and dark. Continuous and pulsed noises of 50, 60, 70, 80 and 90 dB were presented under each illumination condition. While noise intensity altered activity of all age groups, it interacted with illumination and age, resulting in different sensory-dependent patterns of activity in each age group. The results are interpreted in terms of arousal theory and potential functional development of CNS structures regulating the effects of ambient sensory input on behavior.     

Antidepressant treatment of children: clinical relapse is unrelated to tricyclic plasma concentrations

Plasma concentrations of imipramine and amitriptyline and their desmethylated metabolites were measured in 20 children being treated for major depressive illness 2 wk. and 5 to 10 wk. after achieving drug dosages of 2.25 mg/kg body weight. At 2 wk. all children had exhibited clinical improvement, but by 10 wk. 4 of the 10 children treated with imipramine and 5 of the 10 children treated with amitriptyline had experienced clinical relapse of depressive symptoms. Tricyclic antidepressant plasma concentrations and ratios were comparable in the subgroups of children who maintained their clinical improvement and those who relapsed. There was no evidence of a systematic decline in plasma tricyclic antidepressant concentrations in those children who relapsed.     

A noninvasive index of hemispheric activity

Tympanic thermometers were used to measure fluctuations in the temperature of the left and right hemispheres of 22 normal high school students while performing verbal and nonverbal visual discrimination tasks. The nonverbal task involving face recognition demonstrated the predicted effect of hemispheric bias on performance: The subjects performed better when they showed a relative rise in right-hemisphere temperature. No significant relationship between hemispheric temperature and level of performance was observed during the verbal task, perhaps owing to the opportunity to treat effectively the nonwords as either linguistic strings or visual patterns. It is concluded that tympanic temperature effectively measures hemispheric activity during cognitive processing.     

Learning effects of knowledge of results upon time estimation

College students of both sexes served as their own controls to test three hypotheses in each of two separate experiments designed to assess the learning effects of knowledge of results upon time estimation. The results indicated that (1) knowledge of results in the form of feedback to the nearest hundredth of a second significantly increased the mean accuracy of time estimations obtained by the method of production, (2) that knowledge of results significantly decreased the variance of the time estimations, and (3) that sex difference as a main effect was not significant in either experiment. A major conclusion of the present study was that variance represents an authentic and independent measure of learning.     

Effects of ball color on horizontal perimetry detection

The subjects were 16 college students assessed as having normal, uncorrected visual abilities. Each subject responded to the appearance of each of five variously colored ball sections as they were introduced into the subjects' visual field. Analysis indicated that colors with luminance values greater than 70 CD/M2 (black, blue, green) were detected further in the horizontal peripheral plane than were colors possessing values less than 36 CD/M2 (red, purple).     

Field dependence as a limiting factor in solving a complex learning problem

Subjects in a prior study of complex learning often experienced difficulty in mastering the task because of an apparent reluctance to release one perceptual field and reconstrue the task on a higher cognitive level. It was hypothesized that were this the correct explanation, the faster learners would be more field independent on a measure of field dependence, since independence has been defined in terms of ease in releasing one's attention from the immediate perceptual field. This hypothesis was tested with 22 undergraduate subjects for whom Group Embedded Figures Test scores were correlated with the number of trials to completion on the complex learning task. A moderate but significant correlation supported the hypothesis.     

Physical exercise, social background, and the well-being of older adult women

28 older women participating in an exercise program were compared to 30 older women not participating in an exercise program on two behavioral measures. There were no significant main effects for participation-nonparticipation in an exercise program. Significant main effects were found, however, for each of three social variables.