What is tDCS?

What is tDCS - Rev6

tDCS stands for Trans cranial 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, where changes in cortical excitability that are directly measurable, usually last from the period of stimulation, plus some after effects ranging from 3 to 90 minutes after the end of treatment. However, a study researching the effects of Trans cranial Direct Current Stimulation on depression found that the beneficial effects of tDCS stimulation were shown to be apparent an entire month after the treatment (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. 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, precise positioning is always 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?

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 (F3), and cathode (negative: black) positioned on Fp2 location, above the right eye brow, with 1mA current for 20min. This montage has been shown to improve many cognitive functions such as working memory, impulse control, reasoning, and learning.

What are some other montages and their uses?

There are many webpages and blogs dedicated to tDCS montages and their effectiveness. Below are a few websites that provide tDCS related montages information.
*The Brain Stimulator, Inc. does not take responsibility and neither supports nor endorses any information that may be presented on these websites.

(Disclosure: A lot of this information has been paraphrased from reddit’s tDCS community as we have found it to be one of the best, all encompassing sources of tDCS information on the internet. Link’s to other helpful sites can be found in the sidebar.)

***Important Note***
This page is provided for informational purposes only. None of this information should be viewed as suggestive or actionable. Do not view this data as absolute fact. It is recommended that you conduct your own research to come up with your own conclusions. None of the statements located on this page are supported by the FDA. The Brain Stimulator, Inc. does not take responsibility for the validity or context of any information on this page. 

Although it is generally believed among researchers that tDCS cannot cause brain damage, it still effects brain function. By using Trans cranial Direct Current Stimulation (tDCS), you are doing so at your own risk and liability.

Last Updated 2/21/2015