Seeing either the forest or the trees: dissociation in visuospatial processing

Traditionally, visuospatial processing has resisted fractionation into functional substrates. Recently, however, it has been shown that the brain honors the distinction between global and local processing of hierarchical visual stimuli: unilateral left hemisphere brain-damaged subjects were impaired in their ability to draw the local forms of a hierarchical design, whereas right hemisphere-damaged patients demonstrated the opposite pattern (Delis, Robertson, & Efron, 1986; Delis, Kiefner, & Fridlund, 1988). The present study reports a similar pronounced dissociation in hierarchical visual processing but in quite different populations and in the absence of focal structural brain damage. Mentally retarded subjects with Williams Syndrome are considerably more impaired in global relative to local analysis, whereas subjects with Down Syndrome display the opposite pattern. These results, in concert with other neuropsychological data, are provocative because they suggest that certain cognitive deficits may cluster even in the absence of frank cerebral damage, just as they cluster following insult to one hemisphere. These findings should provide clues to the interrelationship of components of visuospatial processing and other cognitive functions.     

Evaluating a primary prevention program for children of divorce

The effectiveness of a primary prevention program for children of divorce is evaluated. Subjects included 82 mother-child pairs. Mothers had been separated for 33 months or less and did not have prior histories of using mental health services. Subjects were assigned to one of four conditions: (a) the Children's Support Group alone (CSG), (b) the CSG and the Single Parents' Support Group (SPSG), (c) the SPSG alone, or (d) a no-treatment control group. Data collected before, after, and 5 months following intervention, were analyzed using analyses of covariance with preintervention scores as covariates and pre-post and post-follow-up difference scores as dependent measures. Children in the CSG-alone condition improved most in self-concept and parents in the SPSG-alone condition improved the most in adjustment. Improvements were either maintained or did not change differentially across groups at follow up. Adaptive social skills of CSG-alone children compared to children in the CSG/SPSG groups showed significant post-to-follow-up improvements.     

Central action of substance P: possible role in reward

A series of studies had revealed a dualistic role of post-trial injections of substance P in affecting avoidance behavior depending on the site of the brain in which it is applied. Based on these data, the hypothesis was formulated that substance P has brain site-dependent rewarding and punishing properties, a possibility which was assessed in rats trained on a modified T-maze task. Injections of substance P into the medial forebrain bundle (100 ng) or medial septal nucleus (500 ng) served as a positive reinforcer for conditioned place preference learning in the T maze. Injections into the amygdala (50 ng) or substantia nigra (100 ng) did not have such reinforcing properties.     

Dimesionality of Rotter's locus of control scale: an application of the ‘very simple structure’ technique

The literature on the dimensional structure of Rotter's Locus of Control Scale presents a confused picture, with solutions ranging from two to nine factors reported. In the present study, Revelle and Rocklin's (1979)‘Very Simple Structure’ (VSS) method was used to determine the optimum number of interpretable factors to extract from the two-factor model represented the optimum solution, and that there was no justification for extracting more than two factors for the purpose of subscale construction. Oblique rotations, as compared with orthogonal Varimax rotation, did not improve the goodness-of-fit of the two-factor solution. When data from males and females were analysed separately, there was no evidence of differences in factorial structure. The findings illustrate how the VSS technique, by providing a quantitative basis for deciding how many factors to extract from a data set, can be used to clarify inconclusive results obtaind from the application of conventional psychometric ‘rules of thumb’ in factor analysis.     

Underlying motivation in the approach and avoidance goals of depressed and non-depressed individuals

Neurobiological theories predict decreased approach motivation and increased avoidance motivation in depression, but the results of previous studies have been equivocal. This study addressed a key limitation of previous research by assessing participants' underlying motivation for adopting their goals. Depressed (N=26) and non-depressed (N=33) participants listed approach and avoidance goals and wrote down their underlying reasons for adopting those goals. The groups did not differ on either the number of goals or underlying reasons but when underlying reasons were coded for approach or avoidance motivation depressed participants, compared to controls, showed less approach motivation and more avoidance motivation in relation to their approach goals. There were no effects related to avoidance goals. The results suggest that while the goals of depressed persons appear to be similar to those who are not depressed there are important differences at the level of underlying motivation.