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.     

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.     

Differential diagnosis and different etiologies of monopolar and bipolar phasic psychoses

Monopolar and bipolar phasic psychoses can be differentiated not only on the course but also on the symptom pattern. This applies also to the euphoric forms which usually are still assigned to Manic-depressive illness. The differential diagnosis is presented. Aetiology is completely different in the monopolar and the bipolar phasic psychoses. Manic-depressive illness has a hereditary basic, whereas in the monopolar ("pure") forms loading is very low. Particularly few psychoses among the relatives have been found in the euphoric forms which demonstrates their independency for if they would belong to Manic-depressive illness they necessarily would show the heavy genetic loading of this bipolar illness. In the pure phasic psychoses external causes were detected when we focused on the sibships in which the probands had grown up. The euphoric patients had relatively many older siblings, the depressive ones relatively few older siblings. A similar difference was found in two cycloid psychoses. Transcultural observations as well as shifts in the incidence rate of the psychoses in our times confirmed our results. Prophylactic measures can be derived.     

Community responses following suicide, homicide, and other deaths: the perspective of potential comforters

To determine whether actual responses of potential comforters in the community differ according to cause of death, 83 college students participated in a structured, individual interview. They were asked demographic questions about themselves, the bereaved, and the deceased, and then about various aspects of how they, and others in the community, responded to the death. Students were grouped by their reports of the cause of death (suicide, homicide, accident, natural anticipated death, or natural unanticipated death). When the death was by suicide or homicide, others were perceived as relatively less supportive of the bereaved person. When the death was by suicide, respondents themselves tended more to blame the bereaved person. When the death was by homicide, the bereaved person was perceived as reacting relatively worse. Potential comforters were relatively more shocked when the death was by homicide or accident.     

Testing the dimensionality of the self-consciousness scales

The self-consciousness scale of Fenigstein, Scheier, and Buss (1975) was subjected to internal and external consistency tests based on the classical test theory model. The scale was found to have five underlying dimensions: two for private self-consciousness (viz., self-reflectiveness and internal state awareness), two for public self-consciousness, and one for social anxiety. The confirmatory factor analysis procedures employed by Burnkrant and Page (1984) are shown to be fallible as indicators of unidimensionality. Theoretical implications of newly identified dimensions in the public self-consciousness subscale are discussed.     

Conditional relations by monkeys: Reflexivity, symmetry, and transitivity

Two cynomolgous macaques categorized six colors into two groups of three after conditional discrimination training (zero-delay symbolic match-to-sample). The procedures resulted in the establishment of relations among the elements of each set-relations that were not specifically trained and that can be characterized by the properties of reflexivity, symmetry, and transitivity. Each set of colors was related to a characteristic pattern of responding: One response pattern involved temporal duration (press and hold the response keys); the second response pattern entailed repeated pressing and releasing of the response keys (fixed ratio 8). Six combinations of two colors were trained, three combinations from each set. After discriminative performance stabilized for each monkey, they were tested with 10 additional color combinations, all of which differed from the training combinations. The conditional relations established between test combinations can be characterized as stimulus equivalence. The training procedures were analogous to the procedure of using category names, and have implications for understanding the function of language in the formation of equivalence classes.