Transcranial Direct Current Stimulation (tDCS) is a technology which allows researchers to stimulate certain areas of the brain and to assess its effects on the participant’s performance. This technology consists of a (DC) battery connected via electrodes to the areas of the brain in question. The electrodes are connected to the surface of the participant’s scalp. A saline solution or special medical gel is used for conductance. A positive electrode (anode) stimulates these areas and a negative one (cathode) is used for the returning current. A cathode electrode may also be used to decrease the arousal of certain areas. Its influence can be measured at a behavioral level (before, after and even during the stimulation) and at a neurological level (for example: using EEG before and after the stimulation).
Such technology can be used to treat neurological diseases in order to alleviate the patient’s symptoms. In the field of learning research, tDCS can be used to train participants to improve their performance in tasks that are difficult for them. For example, by stimulating areas on the left hemisphere of the brain that are known to be related to the reading process, dyslexic readers may improve their reading skills. If this stimulation is given as a treatment, some improvements may remain permanent.
Furthermore, it also can provide deeper information about the regions of the brain and their roles. If the performance of a specific task improves significantly after the stimulation of a region of the brain, it may be concluded that such area has a main role in the task performed.
The Edmond J. Safra Center conducts tDCS research with the Starstim device from Neuroelectrics. This is a wireless device that has 8 channels for EEG recordings and transcranial stimulation (for further information click here).