Zapping a patient’s brain with electrical current might sound like an extreme way of improving their mental health. But transcranial direct current stimulation (tDCS) involves gently guiding or 'modulating' brain activity. Using a human thigh here, rather than a brain, researchers test a new method to keep an eye on tDCS treatments in real time. Magnetic resonance imaging (MRI) scanners pick up on tiny changes to invisible magnetic fields caused by the electrical current – revealing different patterns overlaid in orange and blue (middle) on an MRI slice (right) through the thigh. The relationship between current and magnetism is so predictable that tDCS can even be simulated with a computer model (left). Using MRI to monitor tDCS will help in targeting treatments more precisely when tackling psychiatric disorders like drug addiction and depression.
Written by John Ankers
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