TechKnow: How do you plan on measuring your progress with the tDCS headset?
Erica: So I’m using a brain training game called Dual N-Back. So far I’ve tracked my progress with the game without using the tDCS, and I plan to use tDCS, and then practice the game and see how far I can get.
TechKnow: Are you going to record this information? Do you plan on making it available to other people?
Erica: I plan to track the amount of time I’m spending using tDCS and how well I’m performing in the game to see what is correlated.
My sense is that the author’s experience is very similar to that of most tDCS DIYers – an initial flurry of interest followed by frustration at not knowing if ‘it’s working’. That’s why it’s exciting to see easily replicated protocols for self-testing emerging around the Dual N-Back game that is available for free. http://brainworkshop.sourceforge.net/download.html
We’d decided to try the “accelerated learning” montage that had been developed and tested by DARPA. The best test of the device we could come up with was to play Nintendo Wii Mario Kart while brain zapping for 20 minutes — our performance seemed easily measurable (we would just play the same course, over and over) and a lot less violent. At first I was miserable, my green dinosaur avatar, Yoshi, falling off the track on every hairpin turn and barely finishing the course in 3:30. By the end, though, I was cracking 3:00. Of course, there was no control here, no way to tell whether I was simply learning a new skill, but I was cautiously optimistic.
In the weeks that followed, I stuck to it, undertaking 20 minutes of tDCS four to five days a week. I decided to try to teach myself interactive web design, and whenever I’d run the current through my brain, I’d accompany it with 20 minutes on Code Academy, the teach-yourself-to-code megasite. But after a few weeks, the results I was looking for seemed elusive. I was obviously getting better at coding, but there was no way for me to know what role the electricity was playing. And it was still kind of painful. So I quit, and about two months after visiting Bikson’s lab, my tDCS device is gathering dust on a shelf in my office.
Anthony Lee shared the results of his most recent tDCS experiments on Reddit the other night (9/8/12). Using the Cambridge Brain Science Challenge (a set of four tests), he charted his scores over a two month period, comparing results with and without tDCS applied. Check out the video, and if you have questions for Anthony, post them to his Reddit thread.
Update 9/6/12: Found for the first time, a study which equates electrode placement directly with the 10/20 positioning system. The study, Modulating activity in the motor cortex affects performance for the two hands differently depending upon which hemisphere is stimulated, was published in the European Journal of Neuroscience in 2008 and is available to download as a pdf or read in Quick View.
On each day, there was one session for anodal and one for cathodal tDCS, administered while the participants sat in an office chair. On the first day, participants also underwent one session of sham tDCS. For the anodal and cathodal sessions, 1 mA tDCS was applied for 20 min. On one of the testing days, the active electrode was positioned over the participant’s left- hemisphere motor region, centered on C3 of the 10–20 international electroencephalogram system; on the other day, the active electrode was positioned over the motor region of the right hemisphere (centered on C4 of the 10–20 electroencephalogram system). The correspon- dence between C3, C4 and the primary motor cortices of the left and right hemispheres, respectively, has been confirmed by neuroimaging studies (Homan et al., 1987; Herwig et al., 2003; Okamoto et al., 2004)
While the 10/20 positioning system (wikipedia, pdf) does seem straight-forward and easy to understand, most of the electrode sites mentioned in the publications I’m reading don’t refer to it in describing where electrodes are being placed. You’re more likely to see something like: “…after bifrontal tDCS with the anode over the right and the cathode over the left dorsolateral prefrontal cortex (DLPFC).”
But if laypeople are going to be experimenting on themselves, wouldn’t they need some sort of standard reference to enable sharing of specific electrode sites? Wouldn’t you like to be able to say something like, I placed the anode over the right dorsolateral prefronal cortex at F3 and the cathode over the left at F7? In that way it would be easy for someone else to replicate. I was looking for a diagram that would map the 10/20 system over brain regions, but didn’t find exactly what I was looking for. If you have any ideas about this please share in the comments.
In the meantime here are a couple of basic brain info sites I found. These tend toward more basic information. Healthline Brain Map
Cold Springs Harbor 3d Brain Map
Exciting! Reports from self-experimenting starting to come in! In this case the author used the Cambridge Brain Challenge suite of tests to guage the effect of tDCS.
Observations The most immediatley obvious and striking effect of tDCS is the modest but significant increase in Paired Associates score during excitatory tDCS. This score, which measures the ability to remember the locations of objects on a screen, likely correlates with overall working memory, which has been previously shown to be improved by exciting the left DLPFC.
Another striking effect is that of excitatory tDCS on the Odd One Out test, a general test of fluid intelligence. Although it only reached a significance level of 0.41, the 1.6667 point average improvement is this task represents a very large gain in performance…
I think that for me, the thing to do now that I’ve found http://www.cambridgebrainsciences.com, even before I have a tDCS device, is to see if I can affect my test score outcomes using a variety of ‘brain hacks’. For example, this list from Jonah Lehrer http://www.wired.co.uk/magazine/archive/2012/05/features/the-new-rules-of-creativity?page=all Jonah also mentions in various podcasts I’ve listened to around the release of his latest book, “Imagine, How Creativity Works” that both cannabis and alcohol can improve performance on certain kinds of challenges. (Those benefiting from an active right hemisphere.) Imagine having tested sufficiently to be able to state, for instance, that: Under the influence of two 12oz bottles of Guinness consumed within a period of 30 minutes, I was able to increase my Monkey Ladder score by a solid 10%.
From the same Jonah Lehrer Wired article…
When it’s looked in all the obvious places to no avail, you experience mental deadlock. This is a signal to the brain that a new search process is required.
2. Brain activity now shifts to the right hemisphere. According to neuroscientist Mark Beeman, this side is responsible for seeing the big picture. Now you can grasp subtle connotations — the punchline of a joke or the meaning of a metaphor. The switch allows you to explore unexpected associations and perspectives.
3. Thirty seconds before your “aha” moment, there is a sudden burst of brain activity called a “gamma-wave rhythm” which, says Beeman, is the highest electrical frequency generated by the brain. It comes from neurons forming new connections. The spurt of activity comes from the anterior superior temporal gyrus, located on the right hemisphere, just above the ear.