Mixed-Handedness in Young Adult ADHD Populations

Open Access
Morreale, Nicolette Maria
Area of Honors:
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Kristina A Neely, Thesis Supervisor
  • Jinger Gottschall, Honors Advisor
  • ADHD
  • Handedness
  • Mixed-Handedness
  • Cortical Lateralization
Handedness is a lateralized process in which one hemisphere of cerebral cortex exhibits more control than the other, resulting in right-handedness, left-handedness, or mixed-handed. Various neurodevelopmental disorders such as attention deficit hyperactivity disorder (ADHD) exhibit abnormal cortical lateralization that is manifested as a tendency towards mixed-handedness. In the current study, handedness is used as an indicator of cortical lateralization. Handedness is assessed through both performance asymmetries and hand preference measures. The main goals of this study are to 1.) provide evidence for the importance of both hand performance and hand preference measures in the determination of dominance, and to 2.) assess both of these types of measures in a young adult ADHD population to evaluate abnormal cortical lateralization in this group. It is expected that the ADHD population will exhibit a trend towards mixed-handedness, indicating an abnormal process of cortical lateralization when compared to control data from a previous study (Przybyla, Coelho, Akpinar, Kirazci, & Sainburg, 2013). In this study, 8 diagnosed ADHD adults (19-23 years) completed a Kinereach ® reaching task to assess hand performance and the Edinburgh Handedness Inventory along with a Kinereach® hand selection reaching task to assess hand preference. I found that the ADHD patients exhibited a trend towards mixed-handedness in hand performance and hand preference measures. These findings suggest an abnormal cortical lateralization in ADHD, as well as the importance of both performance and preference measures in determining hand dominance.