tDCS works by applying a mild electrical current to specific regions of the brain using special implements called electrodes. The electrical current’s polarity and and where it is applied is crucial because the positive or anode electrodes and the negative or cathode electrodes have different effects on brain cells.
Brain cells that were exposed to positively charged electrical current become more electrically active. They become more likely to fire. That is what is called “priming”. The opposite is true, neurons exposed to negative electrical charge become less likely to fire or “inhibited”.
For example; if you apply positively charge current to a region of the brain responsible for mathematical thinking, it will become “primed” and if you study math while that area is active you will be more likely to learn and become better at math. The important thing to know is that tDCS does not do the work for you; you still have to do the thinking, the studying. Having your neurons primed right when you are trying to learn for that Calculus exam however may be just the extra edge you need to be successful at it.
There are many montages or positioning schemes that can be used to achieve different results. You can prime the areas of your brain responsible for creativity, motor skills, visual processing and much more. Depending on your goals and objectives, you may choose a montage and see how they affects you personally.