title: Impaired practice effects following mild traumatic brain injury: an event-related potential investigation.
abstract: BACKGROUND
  The negative effects of mild traumatic brain injury (mTBI) on attention are well established. Effects of practice on neuropsychological test performance have also been long recognized and more recently linked to electrophysiological indices of information processing.
  
  
  OBJECTIVE
  The current study examined the behavioural and electrophysiological impact of mTBI on consistent practice of a neuropsychological test of attention.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Adult participants with a history of mild TBI (n = 10; time since injury > 2 months, mean = 15.2 months) and healthy matched controls (n = 10) completed the Paced Auditory Serial Addition Task (PASAT) at four separate sessions. Event-related potentials (ERPs) were simultaneously recorded.
  
  
  RESULTS
  Accuracy of PASAT performance in both groups improved significantly with practice. In healthy controls behavioural improvements were associated with significant attenuation of a frontally distributed ERP component marker of executive attention. These executive attention demands did not appear to ease with consistent practice in the mTBI group, who also endorsed more concussion-related symptoms.
  
  
  CONCLUSIONS
  These preliminary results suggest sustained mental effort is required to achieve 'normal' performance levels following mTBI and support the use of practice-related, ERP indices of recovery from mTBI as a sensitive correlate of persistent post-concussion symptoms.
authors.affiliation: School of Psychology, Australian Catholic University , Strathfield, NSW , Australia .
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Rogers
authors.forename: Allison M
authors.initials: AM
authors.lastname: Fox
authors.forename: James
authors.initials: J
authors.lastname: Donnelly
mesh_terms: D001288:Attention; D001924:Brain Concussion / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D038223:Post-Concussion Syndrome / Q000503:physiopathology; D011214:Practice, Psychological; D011446:Prospective Studies; D020127:Recovery of Function; D015203:Reproducibility of Results; D013647:Task Performance and Analysis; D015599:Trauma Severity Indices
keywords: Attention; PASAT; event-related potentials; mild TBI; practice effects