title: Decreased cortical response to verbal working memory following sleep deprivation.
abstract: OBJECTIVE
  To investigate the cerebral hemodynamic response to verbal working memory following sleep deprivation.
  
  
  METHODS
  Subjects were scheduled for 3 functional magnetic resonance imaging scanning visits: an initial screening day (screening state), after a normal night of sleep (rested state), and after 30 hours of sleep deprivation (sleep-deprivation state). Subjects performed the Sternberg working memory task alternated with a control task during an approximate 13-minute functional magnetic resonance imaging scan.
  
  
  METHODS
  Inpatient General Clinical Research Center and outpatient functional magnetic resonance imaging center.
  
  
  METHODS
  Results from 33 men (mean age, 28.6 +/- 6.6 years) were included in the final analyses.
  
  
  METHODS
  None.
  
  
  RESULTS
  Subjects performed the same Sternberg working memory task at the 3 states within the magnetic resonance imaging scanner. Neuroimaging data revealed that, in the screening and rested states, the brain regions activated by the Sternberg working memory task were found in the left dorsolateral prefrontal cortex, Broca's area, supplementary motor area, right ventrolateral prefrontal cortex, and the bilateral posterior parietal cortexes. After 30 hours of sleep deprivation, the activations in these brain regions significantly decreased, especially in the bilateral posterior parietal cortices. Task performance also decreased. A repeated-measures analysis of variance revealed that subjects at the screening and rested states had similar activation patterns, with each having significantly more activation than during the sleep-deprivation state.
  
  
  CONCLUSIONS
  These results suggest that human sleep-deprivation deficits are not caused solely or even predominantly by prefrontal cortex dysfunction and that the paretal cortex, in particular, and other brain regions involved in verbal working memory exhibit significant sleep-deprivation vulnerability.
authors.affiliation: Brain Stimulation Laboratory, Medical University of South Carolina, Charleston 29425, USA. muq@musc.edu
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Mu
authors.forename: Ziad
authors.initials: Z
authors.lastname: Nahas
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Johnson
authors.forename: Kaori
authors.initials: K
authors.lastname: Yamanaka
authors.forename: Alexander
authors.initials: A
authors.lastname: Mishory
authors.forename: Jejo
authors.initials: J
authors.lastname: Koola
authors.forename: Sarah
authors.initials: S
authors.lastname: Hill
authors.forename: Michael D
authors.initials: MD
authors.lastname: Horner
authors.forename: Daryl E
authors.initials: DE
authors.lastname: Bohning
authors.forename: Mark S
authors.initials: MS
authors.lastname: George
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory; D008875:Middle Aged; D012146:Rest; D012892:Sleep Deprivation / Q000503:physiopathology*; D013060:Speech; D013997:Time Factors