title: Hemispheric and executive influences on low-level language processing after traumatic brain injury.
abstract: OBJECTIVE
  The purpose of this study was to examine whether minor high-level language deficits found after traumatic brain injury (TBI) might be due to low-level language processing issues or executive control influences. A possible mechanism was also investigated.
  
  
  METHODS
  Nineteen age- and education-matched healthy controls (16 M, 3 F) and 19 persons who had experienced a complicated mild, moderate or severe TBI between 1-3 years prior (16 M, 3 F; mean GCS = 9.44) participated in two computerized behavioural experiments utilizing two paradigms standard in the psycholinguistic literature (priming with lexical decision and verb generation), which included trials of greater and lesser executive demand.
  
  
  RESULTS
  Response time and accuracy differences were found in both experiments, indicating deficits in single-word processing for the patient group. Disproportionate difficulty was found for trials which included an executive component. Right visual field (left hemisphere) preferences were found to be stronger in the TBI group than in controls.
  
  
  CONCLUSIONS
  Results suggest that persons with TBI may have difficulties in processing single words alone, especially under conditions of increased executive demand, and that atypical patterns of hemispheric recruitment may be associated with these difficulties.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pennsylvania, USA. kcr9@pitt.edu
authors.forename: Kathryn C
authors.initials: KC
authors.lastname: Russell
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Arenth
authors.forename: Joelle M
authors.initials: JM
authors.lastname: Scanlon
authors.forename: Lauren
authors.initials: L
authors.lastname: Kessler
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Ricker
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001930:Brain Injuries / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D004185:Disability Evaluation; D005071:Evoked Potentials; D056344:Executive Function; D005260:Female; D006801:Humans; D007806:Language Disorders / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D007807:Language Tests; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time; D012720:Severity of Illness Index; D055815:Young Adult