What is tDCS?

What is tDCS - Rev6

tDCS stands for Transcranial Direct Current Stimulation and is a form of neurostimulation (also known as neuromodulation) where very low levels of constant current are delivered to specifically targeted areas of the brain, often producing profound results. It was originally developed to help patients with brain injuries such as strokes, however tests on healthy adults demonstrated that tDCS can increase cognitive performance on a variety of tasks, depending on the area of the brain being stimulated. Scientific studies have shown that tDCS has the ability to enhance language and mathematical ability, attention span, problem solving, memory, and coordination. In addition, tDCS has also been documented as having impressive potential to treat depression, anxiety, PTSD, as well as chronic pain.

The Human Brain
To really understand tDCS, you must understand the human brain. The brain is the most complex organ in the human body, comprised of an intricate network of BILLIONS of nerve cells, called neurons. These special cells control and react to everything that happens in our bodies. The neurons in your brain communicate to each other using tiny electrical, and chemical impulses called synapses. Electrical synapses, unlike chemical synapses, conduct nerve impulses faster (approximately 10 times faster), causing vital information to pass from neuron to neuron more quickly.

 

In other words, tDCS allows you to unlock your brain’s true potential!

 

How long do effects from tDCS last?
The immediate effects usually last anywhere from 5 to 90 minutes after the end of the stimulation session. Some research has shown that repetitive stimulation, for example on a daily basis for one week, can educe longer lasting, and more “ingrained” effects. Additionally, a study on depression found that the beneficial effects of tDCS stimulation were shown to be apparent an entire month after the treatment (link). Furthermore, one study (considered anecdotal, not yet confirmed) recorded a lasting cognitive enhancement effect resulting from Transcranial Direct Current Stimulation ONE YEAR after the initial stimulation study (link).

How much power should I use?
Because this technology is fairly new, it’s always recommended to refer to scientific studies. The vast majority of studies conducted with this technology utilize current within the 0.5 – 2.0mA range, as do our products. In our research, it seems that currents below 0.5mA may not produce noticeable results, while currents above 2mA have not yet been researched thoroughly enough to prove safe and efficient. Depending on the application, it is generally believed that higher current sessions produce effects that last longer after the end of stimulation (link).

How long should a session last?
The general consensus is anywhere between 5 to 30 minutes, with the most common professional research sessions lasting 20 or 30 minutes. Additionally, in clinical research, it seems that a five minute period of stimulation is the minimum requirement to produce tDCS effects that last after the session is over (link).

How do I know where to position the electrodes?
First, you need to familiarize yourself with position codes, such as the International 10-20 System (link). As you research different montages (or tDCS placements), you will refer to this chart to understand what placement the author is discussing. While it is easy to visually estimate electrode placement based on the International 10-20 System, or by using online guides (such as the ones listed on our tDCS Placements page), precise positioning is recommended. Precise positioning involves measuring distances on your head using anatomical landmarks. A good guide on this can be found here. It’s also good to familiarize yourself with the names and basic functions of the various cortexes of the brain. The more you know, the more you grow!

Direction of tDCS Current

 

 

 

 

 

 

 

What are montages and protocols?

For a more thorough list of tDCS terminology, see our tDCS terms & definitions page.

Montages are the many different possible tDCS positions of both the anode and cathode electrodes on the body. The Protocol is actually a combination of the tDCS montage (electrode position) being used, the current level being used, and the total duration of the session. The most officially researched protocol is anodal (positive: red) stimulation of the left dorsolateral prefrontal cortex (L-DLPFC – F3), and cathode (negative: black) positioned on right Frontopolor (Fp2), located on the forehead above the right eyebrow, using 1mA of current for 20 minutes. This montage has been shown to improve many cognitive functions such as working memory, impulse control, reasoning, and learning.

What are some montages and their uses?

There are many websites which provide information on tDCS montages, electrode placement instructions, and types of effects to be expected. Below are a few of the most reliable websites currently providing tDCS electrode montage placement information. In particular, Total tDCS provides 3D graphics of the head, which makes estimating electrode placement much easier.

 

 

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Last Updated 4/19/2017


You can find links to other helpful sites in the sidebar on the right of this page. The Brain Stimulator, Inc. is not responsible for any information located on external websites. The contents of this website, such as text, graphics, images and other material are intended for informational and educational purposes only and should not be construed as medical advice. The contents of this website are not intended to substitute for professional medical advice, diagnosis or treatment. Although we work to keep the information on this site as up to date and accurate as possible, The Brain Stimulator, Inc. disclaims any warranty concerning its accuracy, timeliness and completeness of content, and any other warranty, express or implied, including warranties of merchantability or fitness for a particular purpose. The Brain Stimulator, Inc. assumes no duty to correct or update this website nor to resolve or clarify any inconsistent information. By accessing this website and viewing its content you agree to the acceptance of these terms. Some of this information has been paraphrased from reddit’s tDCS community, as we have found it to be one of the best resources for tDCS information. You can find links to other helpful sites in the sidebar on the right of this page.