Strategic hand use preferences and hemispheric specialization in tactual reading: impact of the demands of perceptual encoding

Four reading-related, information-processing tasks were administered to right-handed blind readers of braille who differed in level of reading skill and in preference for using the right hand or the left hand when required to read text with just one hand. The tasks were letter identification, same-different matching of letters that differed in tactual similarity, short-term memory for lists of words that varied in tactual and phonological similarity, and paragraph reading with and without a concurrent memory load of digits. The results showed interactions between hand preference and the hand that was actually used to read the stimulus materials, such that left preferrers were significantly faster and more accurate with their left hands than with their right hands whereas right preferrers were slightly but usually not significantly faster with their right hands than with their left hands. In all cases, the absolute magnitude of the left-hand advantage among left preferrers was substantially larger than the right-hand advantage among right preferrers. The results suggest that encoding strategies for dealing with braille are reflected in hand preference and that such strategies operate to modify an underlying but somewhat plastic superiority of the right hemisphere for dealing with the perceptual requirements of tactual reading. These requirements are not the same as those of visual reading, leading to some differences in patterns of hemispheric specialization between readers of braille and readers of print.     

The effects of continuous phonation on Xenon-inhalation air curves (of the kind used in deriving regional cerebral blood flow)

Regional cerebral blood flow (rCBF) may be measured with inhalation techniques that use end-expired values of radioactivity to estimate the isotope concentration in arterial blood. These end-expired data are used as an input function in a mathematical equation to derive rCBF. End-expired air is assumed normally to be in equilibrium with the arterial blood at the alveolar surface of the lung during regular (passive) breathing; this assumption may not be valid during continuous phonation. We therefore have analyzed breathing (inhalation/exhalation) patterns and end-expired radioactivity (¹³³Xe) during (1) speaking, (2) singing, and (3) humming of the national anthem, and also during (4) passive breathing. Statistically significant differences in breathing patterns were measured between a group of nonmusicians and two groups of musicians (singers) during the phonation tasks: The nonmusicians breathed more often (and more rapidly) and exhibited less variability in their breathing patterns than did the musicians. Notwithstanding these differences, the shapes of smoothed functions derived from the end-expired values were not influenced appreciably during phonation (except possibly during talking). The latter finding suggests that estimates of rCBF derived with these data should not be confounded seriously because of the continuous phonation.     

Psychotropic drug treatment among learning-disabled,educable mentally retarded,and seriously emotionally disturbed students

Psychotropic drug treatment in learning-disabled (LD), educable mentally retarded (EMR), and seriously emotionally disturbed (ED) children and adolescents receiving public school special education services was examined. The findings indicated that while treatment prevalence rates for EMR and ED groups were comparable, the rate for LD students was much lower. In the LD sample, pharmacotherapy was associated with higher ratings of behavioral deviance, longer placement in special education, less social integration, and greater peer rejection, which suggests that symptom severity is an important determiner of pharmacotherapy in this population.     

Locational representation in imagery: The third dimension

Six experiments were conducted to test the relative processing characteristics of picture-plane and three-dimensional imagery as indexed by tasks that required subjects to keep track of successive locations in multiunit visual displays. Subjects were shown symmetrical displays either drawn on cardboard or constructed with three-dimensional blocks. They then were required to imagine these matrices and follow pathways through a series of adjacent squares (blocks) within the matrices. The pathways were described by a series of verbal terms that indicated the direction of the next square (block) in the pathway. Subjects experienced difficulty in performing the task with picture-plane displays composed of as few as 16 squares (4×4), but they rarely made errors with a three-dimensional matrix of 27 blocks (3×3×3). Performance with the three-dimensional task dropped dramatically when the matrix size was increased to 4×4×4. The results replicated previous findings that the image processing capacity for location in two-dimensional imagery is about three units in each direction, and they indicate that adding the depth dimension increases the capacity for representation of spatial location in imagery.     

Self-perceived and independently observed competence of young adolescents as a function of parental marital conflict and recent divorce

The self-perceived and independently observed cognitive and social competence of young adolescents as a function of parental conflict and recent divorce was investigated. Subjects were 40 young adolescents between the ages of 11 years 1 month and 15 years 1 month. A 2×2 factorial design was used, with the independent variables being parental marital status (married vs. recently divorced) and parental conflict (high vs. low). Dependent variables included the following measures of adolescent competence: adolescent-completed measures of self-perceived competence, teacher-completed measures, behavioral observations, and school grades. The results indicated that the level of parental conflict, rather than parental marital status, appears to be the critical variable associated with adolescents' independently observed levels of cognitive and social competence. In regard to adolescents' self-perceived levels of cognitive and social competence, parental marital status was found to be the critical variable. The implications of these findings are discussed.This research was supported by the William T. Grant Foundation and the University of Georgia's Institute for Behavioral Research.     

The interactional teaching patterns of mothers and fathers with their popular,moderately popular,or unpopular children

The interactional teaching strategies of mothers and fathers toward their sociometrically determined popular, moderately popular, or unpopular children, and children's responses to them were examined during a structured puzzle task in a laboratory setting. Parents of popular children used more explanations in aiding their children to complete the puzzle task than parents of moderately popular or unpopular children. Mothers were more likely to offer suggestions, use explanations, and ask questions during the puzzle task than fathers. Analysis of children's responses revealed that popular children were more likely to ignore imperatives by their parents compared with unpopular children, while unpopular children showed a tendency to be more cooperative following imperatives by parents than popular children. Finally, popular children were less likely to ignore but were more likely to go off task following suggestions by parents than either unpopular or moderately popular children. The data are discussed with respect to the possible link between parental socialization patterns and children's popularity in the peer group and the need to consider the interaction patterns in both the peer and parent-child systems for intervention purposes.Portions of this paper were presented by the first author at the Banff International Conference on Behavioral Science, Banff, Alberta, Canada, 1984. The research was supported through the Western Regional Project W144, Development of Social Competencies in Children, with funding from Science and Education Administration/Cooperative Research of the USDA and Utah State University Agricultural Experiment Station. We would like to thank the parents and children for their participation, and Nina Mounts, Maria Norton, Carla Seamons, Soheila Sobhani, and Joan Wareham for their assistance with varying aspects of coding and data analysis.     

What learning-disabled readers fail to retrieve on verbal dichotic tests: A problem of encoding,retrieval, or storage?

Three theoretical models were assessed as a framework for capturing learning-disabled readers' faulty word retrieval. To this end, learning-disabled and skilled readers were compared on verbal dichotic listening tasks for free recall and cued recall of word lists organized by semantic, phonemic, and structural features. The results indicated that disabled readers were comparable on free recall but were inferior to skilled readers on cued recall. No ability group differences were found for categorical and noncategorical recall intrusions during the cued recall phase. Cued recall performance was further analyzed for individual differences in memory trace structure (via the Tulving & Watkins, 1975, reduction method), ear asymmetry, and the allocation of attention to word features prior to cuing. Results indicated that during the cued recall phase, disabled readers' memory traces were inferior in structure to those of skilled readers, even though the two ability groups produced comparable symmetrical recall patterns for the ear presentations. Further, disabled readers had lower selective attention scores for the interhemispheric processing of information prior to cuing than did skilled readers. Taken together, the results suggest that, prior to cued recall, disabled readers suffer from attentional difficulties during interhemispheric processing, which in turn influences the structural formation of their memory trace.This research was supported by a grant from the U.S. Office of Special Education and Rehabilitative Services. Special appreciation is given to Greelley District IV schools for providing subjects, to Missy Reda and Stephanie Contros for the data collection, and to two anonymous reviewers for their critical comments on a draft of this article.     

Accelerated development of cardiac sympathetic responses in spontaneously hypertensive (SHR) rats

The functional development of cardiac and adrenal medullary responses to reflex activation of the sympathetic nervous system was studied in preweanling spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) normotensive rats. Pups of the two strains received injections of insulin or saline at 2, 4, 8, 12, or 16 days of age and were sacrificed 3 h later. Insulin administration produces a significant decrease in circulating levels of glucose which in turn results in a centrally mediated increase in sympathetic outflow. The induction of ornithine decarboxylase (ODC) in heart and the depletion of epinephrine from the adrenal medulla served as tissue markers of functional sympathetic neurotransmission. WKY and SHR pups had comparable levels of ODC activity in heart under basal conditions. In contrast, levels of catecholamines in the adrenals were greater in SHR pups at 2 and 4 days of age. Following insulin administration, SHR pups exhibited a greater induction of cardiac ODC activity at 2, 4, and 8 days of age compared to age-matched WKY controls. However, there were no differences between SHR and WKY pups in the magnitude of the adrenal medullary response to insulin-induced hypoglycemia. These alterations in sympathetic-target tissue development during the first postnatal week of life may contribute in part to the higher arterial pressures maintained by SHRs throughout the lifespan.