The effects of atropine and adrenergic antagonists on behavioral arousal in rats

Two experiments investigated the mechanism for changes in measures of behavioral arousal inhibition in rats following administration of atropine. In Experiment 1, 40-day-old rats were given administrations of atropine sulfate, the alpha-, beta-adrenergic blocker labetalol, or both. The drugs, either alone or in combination, increased transport response intensity, whereas both together increased dorsal immobility durations. In Experiment 2, rats were given atropine, the beta-adrenergic antagonist propranolol, the alpha-adrenergic antagonist phentolamine, or a combination of two of the drugs. Propranolol blocked atropine-induced increases in transport response, and phentolamine was without effect. Phentolamine, when combined with atropine, increased dorsal immobility durations. Results are discussed with respect to aspects common to both transport response and dorsal immobility.     

An investigation of perceptual and decisional influences on the perception of hierarchical forms

When observers are asked to identify the global and local dimensions of hierarchical forms, their responses are typically faster when the dimensions are consistent rather than inconsistent. This effect, which we refer to as the dimensional consistency effect, has been demonstrated numerous times in paradigms requiring responses to a single dimension. However, most hypotheses regarding dimensional consistency effects address the simultaneous perception of both dimensions, and the manner in which the information about these dimensions may (or may not) 'interact'. Most explanations of the dimensional consistency effect attribute the effect to perceptual influences. The present study uses the constructs of general recognition theory (Ashby and Townsend, 1986 Psychological Review 93 154-179) to represent the source of the effect in terms of both perceptual and decisional influences. In addition, a complete identification response paradigm was used to collect data on the simultaneous perception of both global and local dimensions of hierarchical forms. Analyses of multidimensional signal detection measures and fits of parametric models of the perceptual space were used to guide inferences, with all sources of evidence pointing to both perceptual and decisional influences.     

Mommy and Daddy like you best: perceived family favouritism in relation to affect, adjustment and family process

Perceived family favouritism and disfavouritism were explored in relation to college students' adjustment, affect and family process. The participants included 127 males and females and 62 of their siblings (age range 18–32 years). Sixty-five per cent of the participants reported favouritism in their families; 24% reported disfavouritism. There was modest sibling agreement on the presence of family favouritism/disfavouritism as well as on who in the family was doing the favouring or disfavouring. The presence of disfavouritism was found to relate to lower family cohesion, higher family disengagement and higher family conflict. Participants who perceived themselves to be disfavoured also reported more frequent shame and more intense fear. Participants who perceived themselves to be favoured reported less frequent shame. Results are discussed in the context of the empirical and clinical literature on sibling and family interaction and the differential treatment of siblings by parents. A clinical case example is provided to illustrate the results and to highlight the implications for family therapy.     

Neuropsychological changes in children with cancer: The treatment of missing data in longitudinal studies

Researchers conducting longitudinal studies with children or adults are inevitably confronted with problems of attrition and missing data. Missing data in longitudinal studies is frequently handled by excluding from analyses those cases for whom data are incomplete. This approach to missing data is not optimal. On the one hand, if data are missing at random, then dropping incomplete cases ignores information collected on those cases that could be used to improve estimates of population parameters (e.g., means, variances, covariances, and growth rates) and improve the power of significance tests of statistical hypotheses. On the other hand, if data are not missing at random, then dropping incomplete cases leads to biased parameter estimates and hypothesis tests that may be internally and externally invalid. This study uses three years of follow-up data from a longitudinal investigation of neuropsychological outcomes of cancer in children to demonstrate the problems presented by missing data in repeated measures designs and some solutions. In evaluating potential biasing effects of attrition, the study extends previous research on neuropsychological outcomes in pediatric cancer by inclusion of patients whose disease had relapsed, and by comparison of surviving and nonsurviving patients. Although the data presented have specific relevance to the study of neuropsychological outcome in pediatric cancer, the problems of missing data and the solutions presented are relevant to a wide variety of diseases and conditions of interest to researchers in child and adult neuropsychology.     

The selective attention of learning-disabled children: Three studies

Three studies were performed to assess the selective attention of learning-disabled (LD) children. In the first study, 10 LD and 16 non-LD children were given the Speeded Classification task. LD children sorted cards more slowly than non-LD children, and children in both groups had trouble ignoring irrelevant information. Non-LD children became more accurate across trials, while LD children did not. In the second study, one group of 13 LD children was taught to accompany their Speeded Classification sorting verbally in an attempt to improve their performance; the other group of LD children (n=12) received no such instruction. The experimental group, however, showed poorer performance across trials compared with the control group. In the third study, the children from Experiments 1 and 2 were given the Central-Incidental Learning task. Older children learned more central memory items than younger children and, LD children learned more incidentally than non-LD children.The authors would like to thank James Merola, Lisa Hart, Donna Woods, and Leonne Paquette for their assistance in this project, and the headmaster, director, teachers, and staff who were so helpful. Parts of this paper were presented at the 1982 meeting of the American Psychological Association.     

Types of private speech produced by hyperactive and nonhyperactive boys

Types and amount of private speech (audible talking that is not addressed to another person) were assessed during the free play of 16 hyperactive and 16 nonhyperactive boys. Verbalizations were coded into nine categories that denoted the boys' level of use of verbal control of their own behavior (Luria, 1961; Kohlberg, Yeager, & Hjertholm; 1968). Differences in amount and type of private speech between hyperactive and nonhyperactive boys were found to indicate that hyperactive boys may be presenting a specific or general cognitive lag in development. Treatment ramifications are discussed.     

Learning disability and hyperactivity: Deficits in selective attention

Differences in performance on a variety of cognitive measures and differences in patterns of ability between learning disabled (LD) and nonlearning disabled (non-LD) children were examined. Younger and older LD and non-LD children were administered tests of central and incidental learning and selective attention. Teacher ratings of classroom hyperactivity were also examined. LD children, particularly the younger ones, performed significantly more poorly than non-LD children on both attention/memory tasks. Performance on the two tasks was consistently interrelated for the non-LD children and less consistently so for the LD subjects. Hyperactivity was also related to poorer performance on the cognitive measures. Results are discussed in terms of components of selective attention.