Left-right differences on timed motor examination in children.

Age-related change in the difference between left- and right-side speed on motor examination may be an important indicator of maturation. Cortical maturation and myelination of the corpus callosum are considered to be related to increased bilateral skill and speed on timed motor tasks. We compared left minus right foot, hand, and finger speed differences using the Revised Physical and Neurological Assessment for Subtle Signs (PANESS; Denckla, 1985); examining 130 typically developing right-handed children (65 boys, 65 girls) ages 7-14. Timed tasks included right and left sets of 20 toe taps, 10 toe-heel alternation sequences, 20 hand pats, 10 hand pronate-supinate sets, 20 finger taps, and 5 sequences of each finger-to-thumb apposition. For each individual, six difference scores between left- and right-sided speeded performances of timed motor tasks were analyzed. Left-right differences decreased significantly with age on toe tapping, heel-toe alternations, hand pronation-supination, finger repetition, and finger sequencing. There were significant gender effects for heel-toe sequences (boys showing a greater left-right difference than girls), and a significant interaction between age and gender for hand pronation-supination, such that the magnitude of the left-right difference was similar for younger, compared with older girls, while the difference was significantly larger for younger, compared to older boys. Speed of performing right and left timed motor tasks equalizes with development; for some tasks, the equalization occurs earlier in girls than in boys.     

Cognitive Deficits in the Early Stages of Alzheimer's Disease

ABSTRACT— Evidence from longitudinal, experimental, and neuroimaging studies converge to indicate that psychological functions other than episodic memory are affected very early in the course of Alzheimer's disease and, indeed, may predate or influence the apparent memory deficits. Changes in personality and difficulty in executive function, especially in terms of attentional and inhibitory control, are especially prominent. Deficits in other types of memory (i.e., semantic memory, conditioning) can also be detected in the early stages of the disease. It is time to update existing diagnostic criteria for this form of dementia in terms of current knowledge of multiple and interacting brain systems.     

BDNF reverses the CTA memory deficits produced by inhibition of protein synthesis

Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators of not only central synaptic plasticity, but also behavioral interactions between an organism and its environment. Our previous studies on the insular cortex (IC), a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA), have demonstrated that intracortical microinfusion of BDNF induces a lasting potentiation of synaptic efficacy in the projection from the basolateral nucleus of the amygdala (Bla) to the IC of adult rats in vivo. Recently, we found that intracortical microinfusion of BDNF previous to CTA training enhances the retention of this task. In this work, we present experimental data showing that acute intracortical delivery of BDNF (2 microg/2 microl per side) reverses the deficit in CTA memory caused by inhibition of insular cortex protein synthesis due to anisomycin administration (100 microg/microl per side) in male adult Wistar rats. These findings suggest that BDNF is a protein synthesis product essential for neocortical long-term memory storage.     

Learning new problem-solving strategies leads to changes in problem representation

Children sometimes solve problems incorrectly because they fail to represent key features of the problems. One potential source of improvements in children's problem representations is learning new problem-solving strategies. Ninety-one 3rd- and 4th-grade students solved mathematical equivalence problems (e.g., 3 + 4 + 6 = 3 + __) and completed a representation assessment in which they briefly viewed similar problems and either reconstructed each problem or identified it in a set of alternatives. Experimental groups then received a lesson about one or both of two solution strategies, the equalize strategy and the add–subtract strategy. A control group received no instruction. All children completed posttest assessments of representation and problem solving. Children taught the equalize strategy improved their problem representations more than those not taught it. This pattern did not hold for the add–subtract strategy. These results indicate that learning new strategies is one source of changes in problem representation. However, some strategies are more effective than others at promoting accurate problem representation.     

Coping with Family Conflict: What’s Helpful and What’s Not for Low-income Adolescents

Family conflict is exacerbated by poverty-related stress and is detrimental to adolescent mental health. Adolescent coping with family conflict has the potential to buffer or exacerbate the negative effects of family conflict on internalizing symptoms. We examined coping with family conflict among 82 low-income adolescents (53.7% female, mean age = 13.5 years at Time 1, SD = 1.98; range 11–18), and their primary caregivers (95% female, mean age = 34.9 years, SD = 7.45). Adolescents were 25.9% Caucasian, 28.4% African American, 38.3% Hispanic, and 7.4% Other (Multi-racial, Native American, or Asian). Results show that family conflict is more strongly associated with internalizing symptoms for adolescents under high levels of poverty-related stress. Regression analyses indicate that secondary control coping moderates the effects of family conflict on internalizing symptoms. In addition, analyses reveal that disengagement coping exacerbates symptoms across time for both adolescent girls and boys. Regression analyses also suggest that primary control coping is helpful for coping with family conflict, but only for girls. Results highlight the importance of examining coping concurrently and across time as well as including moderating effects of gender. Intervention efforts targeting low-income adolescents should incorporate the instruction of secondary control strategies for coping with family conflict.     

Risk perception as a function of risk exposure amongst rock climbers

ObjectivesThe first objective was to examine the extent to which climbers' climbing safety perceived competence (CSPC) and perceived own absolute (POAR) and comparative (PCR) risk of getting seriously injured whilst climbing is related to risk exposure. The second objective was to examine which variables influence POAR and PCR.MethodTwo hundred and thirty-five climbers (M = 32, SD = 10.2 years of age) completed the following questionnaires: a CSPC scale specifically developed to assess perceived ability to practice climbing safely; indirect measures of PCR, consisting in the subtraction of the participants' assessment of their own risks from their assessment of other climbing referents' risks; and the Life Orientation Test-Revised, measuring dispositional optimism (DO). Participants were approached in their practices sites from Mediterranean regions, and were divided into groups based on their climbing practice's risk exposure; that is, high risk: traditional climbing (TRAD; n = 42); moderate risk: leading (LEAD; n = 89); and low risk: either top-roping (TOP; n = 51) or indoor bouldering (IND; n = 53).ResultsAnalyses of variance showed that TRAD expressed higher CSPC and higher POAR than the other groups. PCR also differed amongst the groups. More specifically, TRAD expressed comparative pessimism and LEAD expressed comparative optimism, as their POAR was, respectively, higher and lower than their perceived average climber's risk. TOP and IND perceived their own risk in a similar way to that of the average climber. Regression analyses showed that DO did not influence POAR or PCR. Past injury episode was positively related to POAR and negatively related to the propensity to express comparative optimism, though only amongst TRAD and LEAD.ConclusionsClimbers' risk perception accurately reflected their risk exposure. Climbers whose climbing modality involves higher risks acknowledged so when evaluating their own absolute and comparative risks of getting seriously injured whilst climbing.