Altered frontal pole development affects self-generated spatial working memory in ADHD

Brain Dev. 2016 May;38(5):471-80. doi: 10.1016/j.braindev.2015.11.005. Epub 2015 Dec 18.

Abstract

Background: Spatial working memory (SWM) dysfunction is a feature of attention deficit hyperactivity disorder (ADHD). Previous studies suggested that behavioral performance in self-generated SWM improves through development in children with and without ADHD. Nevertheless, developmental changes in the neural underpinnings of self-generated SWM are unknown.

Method: Using near-infrared spectroscopy, hemodynamic activity in the prefrontal cortex (PFC) was measured in 30 children with ADHD (9.5 ± 1.6 years-old) and 35 TD children (9.0 ± 1.6 years-old) while they performed a self-generated SWM task. We then investigated correlations between age and behavioral performance, and between age and hemodynamic activity in the PFC for each group.

Results: Both groups showed a negative correlation with age and number of errors [ADHD: r(28)=-0.37, p=0.040; TD: r(33)=-0.59, p<0.001], indicating that self-generated SWM improves through development. The TD group showed a positive correlation between age and oxygenated hemoglobin in the frontal pole [10ch: r(33)=0.41, p=0.013; 11ch; r(33)=0.44, p=0.008] and bilateral lateral PFC [4ch: r(33)=0.34, p=0.049; 13ch; r(33)=0.54, p=0.001], while no significant correlation was found in the ADHD group. Furthermore, regression slopes for the frontal pole significantly differed between the TD and ADHD groups [10ch: t(61)=2.35, p=0.021; 11ch: t(61)=2.05, p=0.044].

Conclusion: Children with ADHD showed abnormalities in functional maturation of the frontal pole, which plays a role in manipulating and maintaining information associated with self-generated behavior.

Keywords: Attention deficit hyperactivity disorder (ADHD); Cambridge Automated Neuropsychological Battery (CANTAB®); Development; Near-infrared spectroscopy (NIRS); Prefrontal cortex (PFC); Self-generated spatial working memory (SWM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Attention Deficit Disorder with Hyperactivity / physiopathology*
  • Brain Mapping / methods
  • Case-Control Studies
  • Child
  • Female
  • Frontal Lobe / physiopathology
  • Humans
  • Male
  • Memory, Short-Term / physiology
  • Neuropsychological Tests
  • Prefrontal Cortex / metabolism
  • Spatial Navigation / physiology*
  • Spectroscopy, Near-Infrared / methods