Modulation of the neuronal circuitry subserving working memory in healthy human subjects by repetitive transcranial magnetic stimulation

We studied the effect of repetitive transcranial magnetic stimulation (rTMS ) on changes in regional cerebral blood flow (rCBF) as revealed by positron emission tomography (PET) while subjects performed a 2-back verbal working memory (WM) task. rTMS to the right or left dorsolateral prefrontal cortex (DLPFC), but not to the midline frontal cortex, significantly worsened per formance in the WM task while inducing significant reductions in rCBF at th e stimulation site and in distant brain regions. These results for the firs t time demonstrate the ability of rTMS to produce temporary functional lesi ons in elements of a neuronal network thus changing its distributed activat ions and resulting in behavioral consequences. (C) 2000 Published by Elsevi er Science Ireland Ltd. All rights reserved.