title: Dissociation of working memory impairments and attention-deficit/hyperactivity disorder in the brain.
abstract: Prevailing neuropsychological models of attention-deficit/hyperactivity disorder (ADHD) propose that ADHD arises from deficits in executive functions such as working memory, but accumulating clinical evidence suggests a dissociation between ADHD and executive dysfunctions. This study examined whether ADHD and working memory capacity are behaviorally and neurobiologically separable using functional magnetic resonance imaging (fMRI). Participants diagnosed with ADHD in childhood who subsequently remitted or persisted in their diagnosis as adults were characterized at follow-up in adulthood as either impaired or unimpaired in spatial working memory relative to controls who never had ADHD. ADHD participants with impaired spatial working memory performed worse than controls and ADHD participants with unimpaired working memory during an n-back working memory task while being scanned. Both controls and ADHD participants with unimpaired working memory exhibited significant linearly increasing activation in the inferior frontal junction, precuneus, lingual gyrus, and cerebellum as a function of working-memory load, and these activations did not differ significantly between these groups. ADHD participants with impaired working memory exhibited significant hypoactivation in the same regions, which was significantly different than both control participants and ADHD participants with unimpaired working memory. These findings support both a behavioral and neurobiological dissociation between ADHD and working memory capacity.
authors.affiliation: McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Psychology, Florida International University, FL 33199, USA.
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Mattfeld
authors.affiliation: McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Whitfield-Gabrieli
authors.affiliation: Clinical and Research Program in Pediatric Psychopharmacology, Massachusetts General Hospital, MA 02114, USA; Department of Psychiatry, Massachusetts General Hospital, MA 02114, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Biederman
authors.affiliation: Clinical and Research Program in Pediatric Psychopharmacology, Massachusetts General Hospital, MA 02114, USA; Department of Psychiatry, Massachusetts General Hospital, MA 02114, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Spencer
authors.affiliation: Clinical and Research Program in Pediatric Psychopharmacology, Massachusetts General Hospital, MA 02114, USA; Department of Psychiatry, Massachusetts General Hospital, MA 02114, USA.
authors.forename: Ariel
authors.initials: A
authors.lastname: Brown
authors.affiliation: Clinical and Research Program in Pediatric Psychopharmacology, Massachusetts General Hospital, MA 02114, USA; Department of Psychiatry, Massachusetts General Hospital, MA 02114, USA.
authors.forename: Ronna
authors.initials: R
authors.lastname: Fried
authors.affiliation: McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Psychiatry, Massachusetts General Hospital, MA 02114, USA.
authors.forename: John D E
authors.initials: JD
authors.lastname: Gabrieli
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002648:Child; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000503:physiopathology*; D008570:Memory, Short-Term / Q000502:physiology*
keywords: ADHD; Longitudinal; Working memory; fMRI; n-Back