The odd-even effect in Sudoku puzzles: effects of working memory, aging, and experience.

The odd-even effect in numerical processing has been explained as the easier processing of even numbers compared with odd numbers. We investigated this effect in Sudoku puzzles, a reasoning problem that uses numbers but does not require arithmetic operations. Specifically, we asked whether the odd-even effect occurred with Sudoku puzzles and whether individual differences in working memory (WM), aging, and experience with Sudoku modulated this effect. We manipulated the presence of odd and even numbers in Sudoku puzzles, measured WM with the Wisconsin Card Sorting Test and backward digit span task, tested older and younger adults, and collected Sudoku experience frequency. Performance on Sudoku was more accurate for even puzzles than odd ones. Younger, experienced, and higher-WM participants were more accurate on Sudoku, but these individual difference variables did not interact with the odd-even effect. Odd numbers may impose more cognitive load than even numbers, but future research is needed to examine how age, experience, or WM may influence the odd-even effect.

Metabolic risks in older adults receiving second-generation antipsychotic medication.

Metabolic syndrome is prevalent in older adults and increases the risk of cardiovascular disease. Second-generation antipsychotics (aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone) increase the risk of metabolic syndrome and present many challenges for psychiatrists. In this article, we review the relationships between second-generation antipsychotics and metabolic syndrome with a focus on older adults. Because few studies focus exclusively on older adults, we augment this review with relevant findings from younger adults. The differential risk factors of each medication are reviewed, as are recent findings in monitoring and treating metabolic syndrome. Olanzapine and clozapine are more strongly associated with metabolic risks, whereas aripiprazole and ziprasidone are less associated. Although lifestyle modifications can help to reduce some aspects of metabolic syndrome, lifestyle modifications in conjunction with metformin therapy appear to be most effective.