Transcranial direct current Stimulation – or tDCS – is the technique of applying electrodes to the skull and running a small but perceptible current through them. It’s not much current – normally on the buy of 1 or 2 mA, but the effect of either increasing or decreasing neural activity has led to some interesting studies. [Theo] over on Instructables composed a tutorial for making his own tDCS suppy that will supply 2 mA to electrodes put on the skull for everyone to experiment with.
The basic idea behind tDCS is to put the positive electrode over the part of the brain to be ecstatic or the negative electrode over the part of the brain to be inhibited. This is a well-studied technique that can be utilized to improve mathematical ability. It’s not electroshock therapy (although that is a valid treatment for depression and schizophrenia) in that a seizure is induced; tDCS just applies a small current to specific areas of the brain to excite or inhibit function.
[Theo]’s device is a simple circuit made from a transistor, resistors, and a few diodes to provide about 2 mA to a pair of electrical contacts. With this circuit and a few gel electrode pads for your head, you too can explore direct current stimulation of your brain.
Of course we need to alert you about putting electricity into your head. In any event, here’s a quadcopter / stun gun mashup we made. Don’t do that, either. You might get a takedown request.