Vertex Stimulation as a Control Site for Transcranial Magnet ic Stimulation: A Concurrent TMS/fMRI Study.
Source Brain Stimulation. 9(1):58-64, 2016 Jan-Feb.
Jung J; Bungert A; Bowtell R; Jackson SR. Institution Jung, JeYoung. Neuroscience and Aphasia Research Unit (NARU), School of Psychological Sciences, University of Manchester, UK; WCU Department of Brain and Cognitive Engineering, Korea University, South Korea. Bungert,Andreas. Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, UK. Bowtell,Richard. Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, UK. Jackson, Stephen R. WCU Department of Brain and Cognitive Engineering, Korea University, South Korea; School of Psychology, University of Nottingham, Nottingham, NG72RD, UK.
Vertex Stimulation as a Control Site for Transcranial Magnet ic Stimulation: A Concurrent TMS/fMRI Study. Source Brain Stimulation. 9(1):58-64, 2016 Jan-Feb.
A common control condition for transcranial magnetic stimulation (TMS) studies is to apply stimulation at the vertex . An assumption of vertex stimulation is that it has relatively lit tle influence over on-going brain processes involved in most experimental tasks, however there has been little attempt to measure neural ch anges linked to vertex TMS. Here we directly test this assumption by using a concurrent TMS/fMRI paradigm in which we investigate fMRI blood-oxygenation-level-dependent (BOLD) signal changes across the whole brain linked to vertex stimulation.
Thirty-two healthy participants to part in this study. Twenty-one were stimulated at the vertex, at 120% of resting motor thresho ld (RMT), with short bursts of 1Hz TMS, while functional magnetic resonance imaging (fMRI) BOLD images were acquired. As a control condition, we delivered TMS pulses over the left primary motor cortex using identical paramet ers to 11 other participants.
Vertex stimulation did not evoke increased BOLD activation at the stimulated site. By contrast we observed widespread BOLD deactiv ations across the brain, including regions within the default mode network (DMN). To examine the effects of vertex stimulation a functional connectivity analysis was conducted.
The results demonstrated that stimulating the vertex wi th suprathreshold TMS reduced neural activity in brain regions related to the DMN but did not influence the functional connectivity of this network. Our findings provide brain imaging evidence in support of the use of vertex simulation as a control condition in TMS but confirm th at vertex TMS induces regional widespread decreases in BOLD activation.
Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
Publication Type Journal Article. Research Support, Non-U.S. Gov’t.