Linda Forssman

The relation between working memory components and ADHD symptoms from a developmental perspective.

The objective was to examine the relations between attention deficit hyperactivity disorder (ADHD) symptoms and four working memory (WM) components (short-term memory and central executive in verbal and visuospatial domains) in 284 6–16-year-old children from the general population. The results showed that verbal and visuospatial short-term memory and verbal central executive uniquely contributed to inattention symptoms. Age interacted with verbal short-term memory in predicting inattention, with the relation being stronger in older children. These findings support the notion of ADHD as a developmental disorder, with changes in associated neuropsychological deficits across time. The results further indicate ADHD-related deficits in several specific WM components.

A graphical user interface for infant ERP analysis

Recording of event-related potentials (ERPs) is one of the best-suited technologies for examining brain function in human infants. Yet the existing software packages are not optimized for the unique requirements of analyzing artifact-prone ERP data from infants. We developed a new graphical user interface that enables an efficient implementation of a two-stage approach to the analysis of infant ERPs. In the first stage, video records of infant behavior are synchronized with ERPs at the level of individual trials to reject epochs with noncompliant behavior and other artifacts. In the second stage, the interface calls MATLAB and EEGLAB (Delorme & Makeig, Journal of Neuroscience Methods 134(1):9–21, 2004) functions for further preprocessing of the ERP signal itself (i.e., filtering, artifact removal, interpolation, and rereferencing). Finally, methods are included for data visualization and analysis by using bootstrapped group averages. Analyses of simulated and real EEG data demonstrated that the proposed approach can be effectively used to establish task compliance, remove various types of artifacts, and perform representative visualizations and statistical comparisons of ERPs. The interface is available for download from http://www.uta.fi/med/icl/methods/eeg.html in a format that is widely applicable to ERP studies with special populations and open for further editing by users.

Independent contributions of cognitive functioning and social risk factors to symptoms of ADHD in two nordic populations-based cohorts.

This study examined independent contributions of executive functioning (EF), state regulation (SR), and social risk factors to symptom dimensions of attention deficit hyperactivity disorder (ADHD) in two cohorts, which included 221 Norwegian children and 294 Finnish adolescents. Independent contributions of EF and SR were shown in the Norwegian cohort and EF contributed independently in the Finnish cohort. When controlling for each symptom dimension, cognitive functioning and social risk factors were differentially associated with inattention and hyperactivity/impulsivity symptoms. The results show the need to include both social risk factors and cognitive functioning to obtain a better understanding of ADHD symptoms.

Cognitive Functioning and Family Risk Factors in Relation to Symptom Behaviors of ADHD and ODD in Adolescents.

Objective: In this study, the authors investigated whether ADHD and oppositional defiant disorder (ODD) behaviors share associations with problems in cognitive functioning and/or family risk factors in adolescence. This was done by examining independent as well as specific associations of cognitive functioning and family risk factors with ADHD and ODD behaviors. Method: A sample of 120 adolescents from the general population was assessed on various cognitive tasks. ADHD and ODD behaviors were measured through parental and teacher ratings based on Diagnostic and Statistical Manual of Mental Disorders (4th edition) criteria. Parents and adolescents provided information regarding measures of family risk factors. Results: The results show that only cognitive functioning was associated with ADHD behaviors, and family risk factors were, independent of cognitive functioning, associated with ODD behaviors. Conclusion: These results suggest that cognitive performance bears a specific significance for ADHD behaviors, whereas family risk factors have specific importance for ODD behaviors.