title: Decreased neural activity and neural connectivity while performing a set-shifting task after inhibiting repetitive transcranial magnetic stimulation on the left dorsal prefrontal cortex.
abstract: BACKGROUND
  Sub-optimal functioning of the dorsal prefrontal cortex (PFC) is associated with executive dysfunction, such as set-shifting deficits, in neurological and psychiatric disorders. We tested this hypothesis by investigating the effect of low-frequency 'inhibiting' off-line repetitive transcranial magnetic stimulation (rTMS) on the left dorsal prefrontal cortex on behavioural performance, neural activity, and network connectivity during the performance of a set-shifting paradigm in healthy elderly (mean age 50+).
  
  
  RESULTS
  Behaviorally, we found a group-by-session interaction for errors on set-shift trials, although post hoc tests did not yield significant findings. In addition, the verum group, when compared with the sham group, displayed reduced task-related activity in the left temporal gyrus, and reduced task-related connectivity of the left PFC with the left postcentral gyrus and posterior insula.
  
  
  CONCLUSIONS
  These results show that low-frequency off-line rTMS on the left dorsal PFC resulted in reduced task-related activity and network connectivity, which was accompanied by a subtle behavioural effect, thereby further corroborating the importance of an optimally functioning PFC in set-shifting.
authors.affiliation: Department of Anatomy and Neurosciences, VU University Medical Center (VUmc), Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. njhmgerrits@gmail.com.|Neuroscience Campus Amsterdam (NCA), Amsterdam, The Netherlands. njhmgerrits@gmail.com.
authors.forename: Niels J H M
authors.initials: NJHM
authors.lastname: Gerrits
authors.affiliation: Department of Anatomy and Neurosciences, VU University Medical Center (VUmc), Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.|Department of Psychiatry, VUmc, Amsterdam, The Netherlands.|Neuroscience Campus Amsterdam (NCA), Amsterdam, The Netherlands.
authors.forename: Odile A
authors.initials: OA
authors.lastname: van den Heuvel
authors.affiliation: Department of Anatomy and Neurosciences, VU University Medical Center (VUmc), Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.|Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands.|Neuroscience Campus Amsterdam (NCA), Amsterdam, The Netherlands.
authors.forename: Ysbrand D
authors.initials: YD
authors.lastname: van der Werf
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D015331:Cohort Studies; D056344:Executive Function / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D016037:Single-Blind Method; D050781:Transcranial Magnetic Stimulation / Q000379:methods