Here’s my experiences with using tDCS (transcranial direct current stimulation) in conjunction with meditation.
I first started using the foc.us device, which is effective, but I found that the standard montage would lead to mild anger/agression, so I have stopped using the standard montage for it. Instead, I use the device from trans-cranial.com. Foc.us would still work with the external electrodes for custom placements.
My first time I kept it on 1mA just to get used to the stimulation, and it was fine. I quickly moved up to 2mA, and now mostly use 2mA.
You can set it from 5–40mins, I usually stick with 10min sessions, if I feel it’s enough, I’ll end it early, and if I feel I can do more and have more time, I’ll simply start another 10min session.
I stick to a constant current setting, which is used in most published research. Below are my notes about the other modes on the foc.us device:
Continuous: The standard mode, and one most often used in controlled studies.
Pulse: This will send short bursts of current, for me it’s enough to produce flashes of light (also known as phosphenes) if placed near the eyes or other nerves which trace back to the optic nerve. I use this setting only when I specifically want to stimulate my optic nerve, otherwise I feel it’s too much voltage for standard stimulation.
Sinus: A gradual increase then decrease of current over 20 second intervals, with 4-5 pulse-like bursts inbetween each wave. This is a bit more intense than Continuous, so when I feel like stepping up the stimulation a bit, I’ll use this instead of Continuous.
Noise: Random variations in voltage, it can spike high enough to produce phosphenes, but since it’s random, it’s a bit too intense for me, I rarely use this setting, and if I do, I feel a bit disoriented afterwards.
Frequency of Use
I use tDCS everyday, usually in the mornings after breakfast. I’ll sometimes use it in certain situations, which I’ll discuss below under Montages and Meditation.
Montages and Meditation
Montage refers to the position of the electrodes, it’s very important to be aware of the anode (positive) and cathode (negative) as these will determine which region you are making more (or less) active.
As noted above, I started using the standard montage for the first few weeks, but after feeling a tendancy towards anger/agression, I stopped using this in favor of custom placements that are based on published studies.
This montage places the anode on the right temple and cathode on the left temple. For me, this increases lateral thinking and creativity. Often, I will do the Standard montage (above), followed by this montage, what I find is that it helps my brain to exercise both capacities, and is a good balance for me. If I only use the Standard Montage, I tend to feel too focused, and not at all creative. An exercise I use this in conjunction with these intelligence tests, which can be very frustrating, but also kind of fun: http://intelligence-test.net. If I get stuck, I’ll sit and meditate for a few minutes or until my mind is very clear, then get back to it with a different approach.
This is with anode (using only one sponge) on the upper portion of the back of the head (known as the supermarginal gyrus), and cathode on the left side at the same position. For me, this stimulates a part of the brain that has been linked to our ability to put ourself into the position of others, thereby increasing empathy.
This works very well in conjunction with Metta (also known as Loving Kindness Meditation) where the goal is to send loving thoughts out to yourself and three others: someone close to you, someone who is neutral, and someone who you’ve had conflict with, this helps break down barriers in your mind about these categories and helps you to be accepting and to have empathy with anyone.
Note: For some of the montages above, you’ll have to flip the device around to make sure you’ve got the right placement of anode and cathode.