title: The prefrontal model revisited: double dissociations between young sleep deprived and elderly subjects on cognitive components of performance.
abstract: OBJECTIVE
  The prefrontal model suggests that total sleep deprivation (TSD) and healthy aging produce parallel cognitive deficits. Here we decompose global performance on two common tasks into component measures of specific cognitive processes to pinpoint the source of impairments in elderly and young TSD participants relative to young controls and to each other.
  
  
  METHODS
  The delayed letter recognition task (DLR) was performed in 3 studies. The psychomotor vigilance task (PVT) was performed in 1 of the DLR studies and 2 additional studies.
  
  
  METHODS
  For DLR, young TSD (n=20, age=24.60 ± 0.62 years) and young control (n=17, age=24.00 ± 2.42); elderly (n=26, age=69.92 ± 1.06). For the PVT, young TSD (n=18, age=26.65 ± 4.57) and young control (n=16, age=25.19 ± 2.90); elderly (n=21, age=71.1 ± 4.92).
  
  
  RESULTS
  Both elderly and young TSD subjects displayed impaired reaction time (RT), our measure of global performance, on both tasks relative to young controls. After decomposing global performance on the DLR, however, a double dissociation was observed as working memory scanning speed was impaired only in elderly subjects while other components of performance were impaired only by TSD. Similarly, for the PVT a second double dissociation was observed as vigilance impairments were present only in TSD while short-term response preparation effects were altered only in the elderly.
  
  
  CONCLUSIONS
  The similarity between TSD and the elderly in impaired performance was evident only when examining global RT. In contrast, when specific cognitive components were examined double dissociations were observed between TSD and elderly subjects. This demonstrates the heterogeneity in those cognitive processes impaired in TSD versus the elderly.
authors.affiliation: Cognitive Neuroscience Division, Taub Institute for Research in Alzheimer’s disease and the Aging Brain.
authors.forename: Adrienne M
authors.initials: AM
authors.lastname: Tucker
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Stern
authors.forename: Robert C
authors.initials: RC
authors.lastname: Basner
authors.forename: Brian C
authors.initials: BC
authors.lastname: Rakitin
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D001288:Attention; D003072:Cognition Disorders / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011597:Psychomotor Performance; D011930:Reaction Time; D012892:Sleep Deprivation / Q000503:physiopathology* / Q000523:psychology*; D013647:Task Performance and Analysis; D055815:Young Adult