Bilateral language: Is the left hemisphere still dominant?

A 13-year-old left-handed boy with a left fronto-parietal vascular malformation evidenced bilateral symmetrical language representation at intracarotid amytal testing. Surgical resection of the parietal motor and frontal premotor area (sparing classical perisylvian language regions) for seizure control resulted in an acute aphasia. Language deficits were still apparent 3 months and to a lesser degree 1 year after surgery. This suggests that when language is bilateral and symmetrical, the left hemisphere may still be dominant or both hemispheres may be necessary to sustain full language competence. Explanations for atypical language localization within the left hemisphere are also discussed.     

Effect of physical attractiveness on opposite- and same-sex evaluations

After reading an essay attributed to a college freshman, male and female college students evaluated both the essay's quality and the writer's ability. By means of a photograph, the subjects knew writer's sex and physical attractiveness (high, medium, or low). The essays also varied in “objective” quality (high, medium, or low). Significant main effects for essay quality were found in all dependent measures and a sigrdficant main effect for physical attractiveness was found for Composite Essay Quality. Analysis of significant three-way interac-tions between physical attractiveness, sex-of-subject, and sex-of-writer for the Composite Essay Quality and Writer's Overall Ability revealed that individuals of high and medium physical attractiveness were evaluated differently by members of the opposite sex or same sex. That is, highly attractive individuals received the highest evaluations from members of the opposite sex, while individuals of medium physical attractiveness received the highest evaluations from members of the same sex. Results are discussed in terms of the importance of physical attractiveness to relationships between members of the same and opposite sex.     

Diabetes and psychological co-morbidity in children with a family history of early-onset type 2 diabetes

The present study was conducted to evaluate for depressive symptoms and undiagnosed diabetes in children with familial history of early-onset type 2 diabetes. Studies have shown that diabetes doubles the risk for depression and that the duration of diabetes is related to the severity of the depression. Individuals with depression are also said to be at greater risk for developing diabetes. In many cases diabetes is detected whilst screening for depression. Fifty-three children aged between 6 and 17 years were screened for diabetes and assessed for depressive symptoms using the Children Depression Rating Scale, revised version (CDRS-R). Thirty-six (68.0 %) of the children with a family history of early-onset type 2 diabetes had CDRS-R scores consistent with likely or very likely major depressive disorders. Depressive symptoms score was predicted best by the number of generations of diabetes in the family, with an associated r = .65 and adjusted R(2) = .41. As the generations of diabetes increased, the more likely it was for a child to have diabetes (r = .38, p = .005). Four (7.5%) of the children were diagnosed with diabetes. The findings suggest that depressive symptoms are common in children with a family history of early onset type 2 diabetes and may co-exist with diabetes. The independent variable that reliably predicted the child depressive symptoms score was the number of generations of diabetes in the family.     

Predicting the size of individual and

An a priori test of the difference engine model (Myerson, Hale, Zheng, Jenkins, & Widaman, 2003) was conducted using a large, diverse sample of individuals who performed three speeded verbal tasks and three speeded visuospatial tasks. Results demonstrated that, as predicted by the model, the group standard deviation (SD) on any task was proportional to the amount of processing required by that task. Both individual performances as well as those of fast and slow subgroups could be accurately predicted by the model using no free parameters, just an individual or subgroup’s mean z-score and the values of theoretical constructs estimated from fits to the group SDs. Taken together, these results are consistent with post hoc analyses reported by Myerson et al. and provide even stronger supporting evidence. In particular, the ability to make quantitative predictions without using any free parameters provides the clearest demonstration to date of the power of an analytic approach on the basis of the difference engine.     

Effects of environmental support on overt and covert visuospatial rehearsal

People can rehearse to-be-remembered locations either overtly, using eye movements, or covertly, using only shifts of spatial attention. The present study examined whether the effectiveness of these two strategies depends on environmental support for rehearsal. In Experiment 1, when environmental support (i.e., the array of possible locations) was present and participants could engage in overt rehearsal during retention intervals, longer intervals resulted in larger spans, whereas in Experiment 2, when support was present but participants could only engage in covert rehearsal, longer intervals resulted in smaller spans. When environmental support was absent, however, longer retention intervals resulted in smaller memory spans regardless of which rehearsal strategies were available. In Experiment 3, analyses of participants’ eye movements revealed that the presence of support increased participants’ fixations of to-be-remembered target locations more than fixations of non-targets, and that this was associated with better memory performance. Further, although the total time fixating targets increased, individual target fixations were actually briefer. Taken together, the present findings suggest that in the presence of environmental support, overt rehearsal is more effective than covert rehearsal at maintaining to-be-remembered locations in working memory, and that having more time for overt rehearsal can actually increase visuospatial memory spans.     

Choice patterns reveal qualitative individual differences among discounting of delayed gains,delayed losses,and probabilistic losses

A new probabilistic losses questionnaire as well as Kirby's delayed gains questionnaire and a previously developed delayed losses questionnaire were administered to a large online sample. Almost all participants showed the positive discounting choice pattern expected on the Kirby questionnaire, decreasing their choice of a delayed gain as time to its receipt increased. In contrast, approximately 15% of the participants showed negative discounting on the delayed losses questionnaire and/or the probabilistic losses questionnaire, decreasing their choice of an immediate loss as time to a delayed loss decreased and/or decreasing their choice of a certain loss as likelihood of the probabilistic loss increased. Mixture model analysis confirmed the existence of these negative discounting subgroups. The inconsistent findings observed in previous research involving delayed/probabilistic losses may be due to differences in the proportion of negative discounters who participated in previous studies. Further research is needed to determine how negative discounting of delayed and probabilistic losses manifests itself in everyday decisions. It should be noted that the presence of individuals who show atypical choice patterns when losses are involved may pose challenges for efforts to modify discounting in order to ameliorate behavioral problems, especially because many such problems concern choices that have negative consequences, often delayed and/or probabilistic.     

Age and individual differences in visuospatial processing speed: Testing the magnification hypothesis

Forty young adults and 40 older adults performed seven visuospatial information processing tasks. Factor analyses of the response times (RTs) yielded a single principal component with a similar composition in both age samples. For both samples, regressing the mean RTs of fast and slow subgroups for the seven tasks (18 conditions) on the corresponding mean RTs for their age group accounted for 99% of the variance. Taken together, these findings suggest that individual differences in processing time were largely task independent. The magnification hypothesis, a simple mathematical model of the interaction between age and ability, is presented. This model correctly predicts the finding that in both the young and the older adult groups, individual differences increased systematically with task difficulty. The magnification hypothesis also explains the regression parameters describing individual differences among young adults and predicts correctly that equivalent parameters describe individual differences among older adults. According to the magnification hypothesis, the RTs of slower individuals are more affected by aging than those of faster individuals, and slower individuals may be more at risk with respect to other biological insults (e.g., changes in health status) as well.