Adolescence is a peak age of onset for many psychiatric disorders and a period for development of internalizing and externalizing symptoms. Previous cross-sectional studies imply a relationship...Show moreAdolescence is a peak age of onset for many psychiatric disorders and a period for development of internalizing and externalizing symptoms. Previous cross-sectional studies imply a relationship between executive function and problem behaviour. However, to understand these relationships and how they develop, more evidence is required and prospective designs are essential. Current prospective study explored the relationships between age, sex, executive function and problem behaviour. In addition, it studied whether executive functions (inhibition, cognitive flexibility, working memory and planning and organizing) predict problem behaviour. A community sample of 175 adolescents between 8-16 years old underwent an MRI scan three times, with a two-year interval. Problem behaviour was measured by the Dutch translated version of the Child Behavior Checklist (CBCL) (Verhulst et al., 1996) and the executive functions were measured by the Dutch translated parent-report version of the Behavior Rating Inventory of Executive Function (BRIEF) (Smidts & Huizinga, 2009). Pearson correlations, Analyses Of Variance (ANOVA), Independent-samples T-tests and Multiple Regression Analyses were performed. The analyses showed strong associations between cognitive flexibility and internalizing problem behaviour, and between inhibition and externalizing problem behaviour. In addition, when comparing sex difference, a significant difference was found between sex and internalizing problem behaviour, and between sex and planning and organizing. Other sex differences were not found. Results from this study suggest that there is an association between poorer executive function skills and the severity of internalizing and externalizing problem behaviour. Our findings also suggest a relationship between sex and internalizing problem behaviour, and between sex and planning and organizing. Effective interventions could be developed in the future to enhance executive functions and decrease the development of clinical problems.Show less
Stroop-like tests measure the ability to control interference created by irrelevant stimuli when one is asked to focus on a specific task. This study aimed to answer whether the interference...Show moreStroop-like tests measure the ability to control interference created by irrelevant stimuli when one is asked to focus on a specific task. This study aimed to answer whether the interference observed during a Stroop-like task is caused by individual differences, which could be done by measuring the stability of the reaction times and interference effect within one session of a Stroop-like task (by dividing the session in two halves). It was hypothesized that both reaction times and interference effect would be stable within one session, with the exception of children under 7 years old, whose ability to control interference is not fully developed yet. The data of previously administered four Stroop-like tasks (color-object; position-object; number-object; and picture-word) in children, adolescents, and young adults, was used and analyzed to address these questions. The results of this study confirmed only the hypothesis for reaction times, while there was an inconsistency in the results of interference effect. The same pattern was observed for the younger children of this study, as they showed a difference from the remaining age groups in reaction times but inconsistency in interference effect. Further exploration is needed in order to understand why interference effect did not show stability within a session of a Stroop-like task.Show less
