Brain Stimulation

What is Brain Stimulation?

Brain stimulation uses electrical or magnetic methods to change neural activity. Invasive methods use surgically implanted devices; non-invasive methods act through devices outside the head. Researchers use these techniques to study brain function, and particular methods are used to treat neurological or psychiatric disorders.

The result depends on the target, stimulation settings, and person. A treatment that helps with one condition does not necessarily improve cognition more generally.

Examples of Brain Stimulation

• Deep Brain Stimulation (DBS)

  Deep brain stimulation (DBS) is an invasive brain stimulation technique that involves the surgical implantation of electrodes into specific brain regions. DBS delivers electrical impulses to modulate the activity of targeted brain areas. It is primarily used to treat movement disorders, such as Parkinson's disease, essential tremor, and dystonia, by targeting regions involved in motor control.

• Transcranial Magnetic Stimulation (TMS)

  Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that uses magnetic fields to stimulate specific brain areas. TMS involves placing a magnetic coil over the scalp, which generates rapidly changing magnetic fields that induce electrical currents in the underlying brain tissue. Specific TMS devices and protocols are used for conditions including depression and migraine. TMS is also a research method; therapeutic findings do not establish general cognitive enhancement.

• Transcranial Direct Current Stimulation (tDCS)

  Transcranial direct current stimulation (tDCS) passes a low-intensity electrical current through electrodes on the scalp. The effects of tDCS depend on electrode placement, current parameters, brain state and the outcome measured. Researchers study clinical and cognitive applications, with results that depend on the particular use.

• Vagus Nerve Stimulation (VNS)

  Vagus nerve stimulation (VNS) is a method that affects brain activity by delivering electrical pulses to the vagus nerve, which connects the brain to organs in the body. VNS is primarily used to treat epilepsy and depression that have not responded to other treatments. VNS is typically invasive, requiring the surgical implantation of a device that delivers electrical stimulation to the vagus nerve, but non-invasive methods are also being explored.

Sources and evidence

• National Institute of Mental Health: Brain Stimulation Therapies. Describes the methods, their uses, and condition-specific evidence.