tDCS (Transcranial Direct Current Stimulation) Laboratory

Apart from the TMS device, the NeuroConn DC-stimulator MD (tDCS) is installed in the tDCS Laboratory of Shue Yan. Much like TMS, tDCS also applies stimulation to the user’s certain brain area noninvasively, yet it is low transcranial current that the tDCS generates, instead of magnetic field.

There are three types of current stimulation of tDCS, namely anodal stimulation, cathodal stimulation, and sham stimulation. The anodal stimulation excites the desired area of neuronal activity whereas the cathodal stimulation inhabits it (The Johns Hopkins University, The Johns Hopkins Hospital, & Johns Hopkins Health System).  Regarding the sham stimulation, it is designed for the control condition of experiments. During sham stimulation, the device emits electric current that would do no effect to the participants. By comparing the result of different stimulation of tDCS, we can study the effect of electric stimulation without being affected by the placebo effect of the participant.

There are several advantages of the tDCS. First, the cost of tDCS is relatively lower than some other noninvasive brain stimulation devices. Besides, it is a portable device, so that it could be carried outside the laboratory when necessary. Moreover, it requires a less complicated process, as the experimenters do not need to personally hold the device during the experiment, since it is fixed to the participant’s head. It is obviously different from the TMS device, which the experimenter needs to hold the coil personally. Furthermore, as mentioned above, the sham stimulation allows the control condition of experiments, which escalates the accuracy of the result by removing the placebo effect. Last and most importantly, the effect of tDCS is much smaller, so that the chance for participants to have adverse effects is highly reduced. The most commonly reported side effect after tDCS is a minor itching or stinging on the scalp.

The tDCS device is also compatible with MRI scans, its versatilities create numerous possibilities in research. For instance, it could be used in the research of brain-based learning and teaching, so as to see the effect of electric current stimulation to the brain to learning behavior. It could also be used on the topics of risk-taking behavior, decision making and so on. It exemplifies the wide range usage of the tDCS device in research.