Master's Theses

Date of Award

2013

Document Type

Thesis

Department

Psychology

Keywords

ADHD, Sequence Learning, Motor Performance, Implicit Procedural learning

Abstract

"A healthy motor system is able to switch and adapt to different environmental contexts and select the most suitable strategy, thus maximizing the efficiency of the movements and save time or energy. Motor hyperactivity in individuals with ADHD is clinically well recognized and can be understood as abnormal motor inhibition. Individuals with ADHD often have problems with responding effectively to a situation that requires a mobilization of complex motor programs. This deficient flexibility of the motor system in ADHD suggests hypofunctioning of the nigral-striatal dopaminergic system. This study used the motor sequence learning paradigm to examine the selection of movement kinematics and force production and modulation in adults with ADHD. A two-by-three mixed design ANOVA, post-hoc independent measure t-tests and Pearson's correlations were performed. Our results found significantly greater reaction time variability in ADHD as compared to controls. Moreover, subjects with ADHD showed a decreased ability to optimize force production when reacting to different contexts despite intact learning. Thus, participants with ADHD seemed to not be able to integrate the new information and feedback from the environment to inform ongoing motor behavior. Our study provides additional support for the notion that individuals with ADHD have basal ganglia abnormalities and has clinical implications for the diagnosis of ADHD. The findings strongly suggest that motor indices should be further explored as possible biomarkers for ADHD and that the neurophysiological networks underlying motor dysfunctions in ADHD warrant further study."

 
 

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