title: Phonological Working Memory Deficits in ADHD Revisited: The Role of Lower Level Information-Processing Deficits in Impaired Working Memory Performance.
abstract: OBJECTIVE
  The current study dissociates lower level information-processing abilities (visual registration/encoding, visual-to-phonological conversion, and response output) and examines their contribution to ADHD-related phonological working memory (PHWM) deficits.
  
  
  METHODS
  Twenty children with ADHD and 15 typically developing (TD) children completed tasks assessing PHWM, visual registration/encoding, visual-to-phonological conversion, and response output.
  
  
  RESULTS
  Relative to TD children, children with ADHD exhibited deficient visual registration/encoding ( d = 0.60), visual-to-phonological conversion ( d = 0.56), and PHWM ( d = 0.72) but faster response output ( d = -0.66). Bias-corrected, bootstrapped mediation analyses revealed that visual registration/encoding, but not visual-to-phonological conversion, partially mediated ADHD-related PHWM impairments. In contrast, faster response output in children with ADHD served as a suppressor variable, such that greater PHWM deficits were observed in children with ADHD after controlling for their faster response output ( d = 0.72 vs. 0.85).
  
  
  CONCLUSIONS
  Results implicate both lower level (visual registration/encoding) and higher order (PHWM) impairments in ADHD. Implications for designing educationally relevant cognitive interventions are discussed.
authors.affiliation: 1 Florida International University, Miami, USA.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Raiker
authors.affiliation: 2 University of Central Florida, Orlando, USA.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Friedman
authors.affiliation: 2 University of Central Florida, Orlando, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Orban
authors.affiliation: 3 Florida State University, Tallahassee, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kofler
authors.affiliation: 4 University of Mississippi Medical Center, Jackson, USA.
authors.forename: Dustin E
authors.initials: DE
authors.lastname: Sarver
authors.affiliation: 2 University of Central Florida, Orlando, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Rapport
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications* / Q000523:psychology; D002648:Child; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000150:complications* / Q000523:psychology; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time; D066229:Speech Sound Disorder
keywords: ADHD; encoding; information processing; phonological conversion; working memory