Neuromodulation is defined by the International Neuromodulation Society (INS) as a field of science, medicine, and bioengineering.
This society defines neuromodulation as “the modification of nerve activity through targeted delivery of a stimulus, such as electrical/magnetic stimulation (or chemical agents), to specific sites of the brain.” Neuromodulation can help restore function or relieve symptoms that have a neural basis.
Neuromodulation works by actively stimulating nerves to produce a natural biological response. Neurostimulation devices involve the application of electrodes (or magnetic coil) to the brain, the spinal cord or peripheral nerves. A low-voltage electrical current (or magnetic pulses) passes from the generator to the nerve, which can either inhibit or facilitate neural processes to modulate/correct abnormal neural pathway behaviour caused by the disease process.
The main non-invasive brain stimulation techniques used at this research unit are:
Transcranial Direct Current Stimulation (tDCS)
In this technique a weak and non-painful direct current delivered through two or more electrodes placed over the scalp. This technique can increase or decrease brain activity in different regions of the brain.
Transcranial Alternative Current Stimulation (tACS)
In this technique a weak and non-painful alternating current delivered through two or more electrodes placed over the scalp. The main mechanisms by which tACS influences brain physiology has been attributed to frequency specific entrainment, that is phase alignment of endogenous brain oscillations to externally applied oscillating electric currents.
Transcranial Pulsed Current Stimulation (tPCS)
In this technique a weak and non-painful pulsatile current delivered through two or more electrodes placed over the scalp. Due to static and dynamic characteristics of this type of stimulation, it is affecting brain based on the underlying mechanisms for the effects of tDCS or tACS.