As I’ve mentioned in previous posts, I have some pretty good experience with tDCS. I’ll try to quickly go through the protocols I’ve been using, and my experiences.
When I first applied tDCS, it was in the middle of a depressive episode with strange behavioral blocks. Such as, I’ve had this inexplicable dread of checking my mail, been unwilling to start or do anything productive, and similar. I have no idea about the exact neuropsychology of it (it would have been interesting to check myself with a QEEG unit if I had one), but I suppose it was some kind of over-inhibition. It’s something that’s characteristic of my basic “personality”, and something that’s caused me much grief in the past.
I applied tDCS in a bifrontal configuration with the anode over F3 (left dlPfC) and the cathode over Fp2 (right supraorbital). This is an extremely widely researched and proven configuration for treating depression, and is associated with increased conscious control over emotions and an improvement of executive functions including short term memory.
A great overview of tDCS montages and their observed effects in experiments is the TDCS State of the Art paper. Another awesome resource everyone should read are the manuals from Trans Cranial Technologies. They have a comprehensive, easy-to-understand manual on the 10-20 QEEG positioning system, proven tDCS montages, and on cortical functions for those who want to experiment with new setups.
The device was extremely simple, consisting of nothing but an array of CRDs (totaling 2.0mA) and a 1k resistor to suppress current spikes. As a bonus I managed to be the idiot I mentioned earlier, and connected my head last to a powered-up loop, so it can be said without doubt that the total current clearly has gone above 2.0mA upon turn-on (which manifested in a weird popping sensation and a feeling of electric shock – though no phosphenes).
The behavioral-cognitive effect was quite noticeable, but I still don’t know if it had more to do with the tDCS or the shock from the transients. Anyway, the behavioral blocks I mentioned were gone in about 5 minutes, and I soon caught up with all the stuff I have been putting off for days or weeks. In total I did 20 minutes of treatment, and disconnected. Upon disconnection, I experienced phosphenes. While from a subjective standpoint I’ve been successful, I decided to put off further experimentation until I’ve built a more secure device.
Later, when I completed the device described in previous posts, I decided to do a 5-day treatment regimen, using the same bifrontal configuration. This time, I always used the manual start/stop pot, and thus avoided any form of transient.
At this point I was not in any particularly bad condition psychologically (apart from a slight slump in motivation), and thus the effects of this treatment were barely noticeable from a subjective standpoint. I did observe a slight “emotional desensitization”, or increased control over my emotional responses. In a kind of Vulcan-ish way.
The treatment markedly did not help with my lack of motivation, which culminated in spending an entire weekend doing literally nothing but watching Game of Thrones. (In a rather positive mood, but that hardly counts in favor.) So it must be said that tDCS is not a magic bullet. It’s a “hardware level” tuning, and will not necessarily alleviate cognitive, “software level” problems.
A walk in the woods
I did a search over the net looking for ways to increase motivation via tDCS. What I did find was a montage based on anodal stimulation of the right dlPfC (F4), supported by some anecdotal evidence, and unsupported by experimental data. The one relevant experiment I found that used this setup failed to provide statistical data to support its effect on goal-oriented behavior. (That said, the failure might be attributed to a bad choice of measurement task, so I didn’t dismiss it out of hand.)
The protocol was 25 minutes daily for 3 days, using 2mA of total current between the anode over F4 and cathode over Fp1. Though there were no studies showing the effectiveness of this montage for motivation or goal-oriented behavior, it was proven to be without negative effects, and was being researched for alleviating alcohol and drug cravings, so I wasn’t particularly worried.
I did notice some reduction in the compulsive-repetitive behavior that is inherent to my genetic condition (there might be a link with the addictological effects of the montage), and slightly better goal-oriented planning, but nothing particularly striking, so I cannot rule out placebo effect. This slight improvement seems to have dissipated after discontinuing the regimen, though.
Refining the depression montage
I have had some worries about the bifrontal setup, as it has both the anode and cathode over areas of the frontal lobe. Later, I found some data supporting the use of an extracranial cathode. In this setup, the anode is placed over the left dlPfC (F3), and the cathode over the contralateral (right) arm.
I’ve done one 5-day regimen using this since, and I have recently started another. It does seem to help a lot – though I haven’t noticed such marked effects as the first experiment, that may also be because I haven’t experienced such marked behavioral blocks since. It’s hard to pinpoint the effect of treatment, but it’s definitely a thing. It’s not really what “is” there, but what “isn’t”. I definitely feel better and more productive when I’m using tDCS.