title: Static Magnetic Field Stimulation over the Visual Cortex Increases Alpha Oscillations and Slows Visual Search in Humans.
abstract: Transcranial static magnetic field stimulation (tSMS) was recently introduced as a promising tool to modulate human cerebral excitability in a noninvasive and portable way. However, a demonstration that static magnetic fields can influence human brain activity and behavior is currently lacking, despite evidence that static magnetic fields interfere with neuronal function in animals. Here we show that transcranial application of a static magnetic field (120-200 mT at 2-3 cm from the magnet surface) over the human occiput produces a focal increase in the power of alpha oscillations in underlying cortex. Critically, this neurophysiological effect of tSMS is paralleled by slowed performance in a visual search task, selectively for the most difficult target detection trials. The typical relationship between prestimulus alpha power over posterior cortical areas and reaction time (RT) to targets during tSMS is altered such that tSMS-dependent increases in alpha power are associated with longer RTs for difficult, but not easy, target detection trials. Our results directly demonstrate that a powerful magnet placed on the scalp modulates normal brain activity and induces behavioral changes in humans.
authors.affiliation: Laboratory for Clinical Neuroscience, Centre of Biomedical Technology, Technical University of Madrid, 28223 Madrid, Spain.
authors.forename: Javier J
authors.initials: JJ
authors.lastname: Gonzalez-Rosa
authors.affiliation: FENNSI Group, and.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Soto-Leon
authors.affiliation: Laboratory for Clinical Neuroscience, Centre of Biomedical Technology, Technical University of Madrid, 28223 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Real
authors.affiliation: FENNSI Group, and.
authors.forename: Carmen
authors.initials: C
authors.lastname: Carrasco-Lopez
authors.affiliation: Neural Bioengineering Group, Hospital Nacional de Parapléjicos, SESCAM, 45071 Toledo, Spain, Centro Integral de Neurociencias A.C., HM Puerta del Sur, Hospitales de Madrid, Móstoles and Medical School, CEU-San Pablo University, 28938 Madrid, Spain, and.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Foffani
authors.affiliation: Laboratory for Clinical Neuroscience, Centre of Biomedical Technology, Technical University of Madrid, 28223 Madrid, Spain, Department of Neuroimaging, Reina Sofia Centre for Alzheimer's Research, 28031 Madrid, Spain.
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Strange
authors.affiliation: FENNSI Group, and antonioo@sescam.jccm.es antonio.oliviero@hotmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Oliviero
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D016037:Single-Blind Method; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult
keywords: EEG; NIBS; TMS; occipital cortex; static magnetic field; visual search