title: Effect of two weeks of rTMS on brain activity in healthy subjects during an n-back task: a randomized double blind study.
abstract: BACKGROUND
  Repetitive transcranial magnetic stimulation (rTMS) has shown significant efficiency in the treatment of several psychiatric disorders. In depressive disorders, the dorsolateral prefrontal cortex (DLPFC) is the main target for rTMS, but the effects of this stimulation on cognitive functions and their neural correlates are not well known. Previous works have established that the left DLPFC is reliably activated during the n-back working memory task.
  
  
  OBJECTIVE
  The aim of this randomized double-blind study was to determine the impact of rTMS applied to the DLPFC on brain activity during an n-back task in healthy subjects.
  
  
  METHODS
  After randomization, twenty subjects received either active treatment (10 sessions; 1 session a day; frequency = 10 Hz; intensity = 110% of motor threshold) or placebo treatment (sham coil). Subjects performed an n-back task during two functional magnetic resonance imaging sessions (one before stimulation, and one after 10 active or sham rTMS sessions).
  
  
  RESULTS
  No significant changes, neither in mood nor in performance in the n-back task, were shown. A significant group-by-time interaction effect was found in the bilateral middle frontal gyrus and in the left caudate nucleus.
  
  
  CONCLUSIONS
  These results show that rTMS applied on the left DLPFC had close and remote effects on brain areas involved in working memory.
authors.affiliation: URC, G03, EPS Ville Evrard, Neuilly-sur-Marne, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Gaudeau-Bosma
authors.forename: Virginie
authors.initials: V
authors.lastname: Moulier
authors.forename: Anne-Camille
authors.initials: AC
authors.lastname: Allard
authors.forename: Djedia
authors.initials: D
authors.lastname: Sidhoumi
authors.forename: Noomane
authors.initials: N
authors.lastname: Bouaziz
authors.forename: Sonia
authors.initials: S
authors.lastname: Braha
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Volle
authors.forename: Dominique
authors.initials: D
authors.lastname: Januel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000502:physiology*; D004311:Double-Blind Method; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D050781:Transcranial Magnetic Stimulation / Q000379:methods*