Perceptual organization of acoustic stimuli by budgerigars (Melopsittacus undulatus): II. Vocal signals

Operant conditioning and multidimensional scaling procedures were used to study auditory perception of complex sounds in the budgerigar. In a same-different discrimination task, budgerigars learned to discriminate among natural vocal signals. Multidimensional scaling procedures were used to arrange these complex acoustic stimuli in a two-dimensional space reflecting perceptual organization. Results show that budgerigars group vocal stimuli according to functional and acoustical categories. Studies with only contact calls show that birds also make within-category discriminations. The acoustic cues in contact calls most salient to budgerigars appear to be quite complex. There is a suggestion that the sex of the signaler may also be encoded in these calls. The results from budgerigars were compared with the results from humans tested on some of the same sets of complex sounds.     

Time went by so slowly: Overestimation of event duration by males and females

In three experiments, 469 subjects watched a short videotape of a bank robbery and later estimated the duration of the tape. Subjects invariably overestimated the durations. Accuracy of time estimation was unrelated to amount of free recall (Experiment 1) or accuracy of memory (Experiment 2). Females overestimated to a greater degree than males (Experiments 2 and 3). A more stressful version of the event produced greater overestimates than a less stressful version (Experiment 3). The relationship between induced arousal and time estimation appears to be different for men and women.     

Acquisition of word-processing skills by younger, middle-age, and older adults

A total of 45 subjects in three age groups (younger, middle-age, older) were trained to word process on microcomputers using a commercial training program and an experimenter-designed test and evaluation protocol. Although all of the subjects mastered the essentials of word processing, the older group took significantly longer to complete the training and evaluation procedures and performed more poorly on a review examination that tested their knowledge of the word-processing commands and techniques. The results are discussed in relation to requirements for trainer assistance, motivational factors, and the need to design training protocols that meet the needs of older adults.     

The assessment of type a behavior in children and adolescents: An overview

The present article presents an overview of the instruments that have been used to assess the Type A behavior pattern in children and adolescents. The development, usage, and psychometric properties of each assessment technique are discussed, with methodological concerns being addressed whenever appropriate. The Matthews Youth Test for Health is the assessment of choice for children, because of its brevity, ease of administration, and adequate psychometric properties. The Hunter-Wolf A-B Rating Scale is desirable only for older, highly literate children. The Adolescent Structured Interview appears to be the most promising device for the adolescent age range. The other adolescent assessment devices are relatively unpopular, difficult to administer, and not always conceptually parallel to existing research on Type A behavior. Recommendations for future research are presented.     

Clinical trial of contemnol tablets (lithium retard Spofa)

A report on the clinical testing of the lithium-retard medicament Contemnol (Spofa). It details the way lithium-retard treatment is objectively and subjectively superior to the earlier and still current general lithium treatment.