Sleep-related factors: associations with poor attention and depressive symptoms.

BACKGROUND: Sleep duration is known to be associated with depression and attention deficits in children, though the majority of studies have focused on adolescents. Attention problems and depressive symptoms related to sleep factors have not been studied simultaneously in the non-clinical child population before. METHODS: Sleep quantity, adverse bedtime behaviour, daytime sleepiness, poor attention and symptoms of depression were assessed using self-report measures. The participants were 11 years old (n = 439). RESULTS: Short sleep duration during the school week is related to poor attention and high depression. It is not a significant predictor of low attention and high depression symptoms in logistic regression analyses. Instead, adverse bedtime behaviour and daytime sleepiness predict them highly significantly. CONCLUSIONS: Short sleep duration is related to poor attention and depressive symptoms as suggested by previous work. However, the significant role of other sleep-related factors calls for further research.

Tower of Hanoi and working memory in adult persons with intellectual disability.

Persons with intellectual disability (ID) have been found to perform more poorly than their mental age would suggest in the visuo-spatial problem solving task Tower of Hanoi (TOH). Inefficient performance has been assumed to be related to inability to use sophisticated problem solving strategies because of restricted working memory capacity. In the present study, the TOH performance of adult persons with ID was found to be equal to that of fluid-intelligence-matched general children. However, persons with ID violated the rules of the TOH more often, and needed more trials to solve the TOH problems than the children did. Visuo-spatial and executive working memory tasks were significantly connected to the TOH performance of persons with ID, whereas phonological working memory tasks were not. Poor inhibition ability was related to the poor performance of subjects with ID in the TOH. We suggest that for persons with ID, TOH performance is determined by individual differences in fluid intelligence, controlled attention, and inhibition ability.