Static Magnetic Field Stimulation over the Visual Cortex Increases Alpha Oscillations and Slows Visual Search in Humans.
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.
['Gonzalez-Rosa|Javier J|JJ|', 'Soto-Leon|Vanesa|V|', 'Real|Pablo|P|', 'Carrasco-Lopez|Carmen|C|', 'Foffani|Guglielmo|G|', 'Strange|Bryan A|BA|', 'Oliviero|Antonio|A|']
D000328:Adult D000513:Alpha Rhythm D018592:Cross-Over Studies D004311:Double-Blind Method D004569:Electroencephalography D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D010775:Photic Stimulation D011597:Psychomotor Performance D011930:Reaction Time D016037:Single-Blind Method D050781:Transcranial Magnetic Stimulation D014793:Visual Cortex D055815:Young Adult
static magnetic field visual search EEG NIBS TMS occipital cortex