Wow! No less than Hank Green ( of the Vlog Brothers) covering tDCS on his SciShow Psych! He sounds a little skeptical! So we have that in common. I pretty much agree with Hank’s perspective, just a couple of thoughts I’d like to share.
Most companies (but not all) know better than to make claims about tDCS. They know they have to be careful making claims of benefits. So where you see a company making a claim, they are most likely basing the claim on legit science. But are the benefits replicable in your situation? Hank refers to the (science) literature as ‘messy’ and he’s right, with different labs coming to opposite conclusions using basically the same experiment protocols.
Hank characterizes the basic function of tDCS as being a training session for neurons. Over time, with repeated stimulation, those neurons will start to fire more. While this is a legitimate description of the approach some research takes, I think a better way to think of it is that tDCS makes it easier for neurons that are already inclined to fire, to do so. As in- you’re focused on a “Where’s Waldo” task, and with the proper stimulation, the task is easier to do, because the targeted neurons have less resistance to firing.
In the third section of his talk (around 30 minute mark), Dr. McConnell discusses an experiment they are working on that uses EEG to monitor sleep, and according to their protocol, turn on a TES device (tACS-like) in order to induce slow wave EEG activity. The practical application is improved memory consolidation in Alzheimer’s patients. Very interesting!
Published on May 14, 2017 Neurology Grand Rounds 3 May 2017 – Transcranial Electrical Stimulation: A Stimulating Discussion of Current Research.
Brice McConnell, MD, PhD
University of Colorado
If you follow the blog you’ll know I’m not savvy enough in the ways of electronics to know a well-constructed DIY circuit when I see it. I’ve generally depended on the Reddit crowd to sort through the pros and cons of DIY tDCS circuit design. Now that there are a handful of professionally developed and readily available devices on the market, I’m not seeing as many DIY projects, but here’s a couple that popped up on Youtube in the last week or so.
The paper, Gamma frequency entrainment attenuates amyloid load and modifies microglia makes clear that the light-flickering affected the visual cortex, which makes sense, as the light reaches the brain through the eyes. But wait, thinks I, what about tACS (transcranial Alternating Current Stimulation)… haven’t I seen numerous papers implying the ability to ‘entrain’ brain waves with tACS? What if you could increase 40hz Gamma in other parts of the brain? (Google Scholar Search: transcranial alternating, entrain, gamma)
But then I discovered that Radiolab just covered this exact story and it’s totally amazing! Really a must listen. So fun to hear the researcher’s amazement at this accidental (sort of) discovery!
So what’s with the photo of the Foc.us v2 device set up for a 40hz tACS session? Just that…
More about The Picower Institute for Learning and Memory at MIT
Each day for two weeks, Bennett would don a headband equipped with moistened sponges and attached to what she called a “big cellphone”—a tDCS stimulator. When she was ready to start the session, a clinician would give her a four-digit code to enter on a keypad, and the current would surge through the wires and into her brain.
Stumbled upon this device today, the Omni Stimulator, which seems to be mostly sold in Australia. That lead to this video where Brendan Morgan makes the case for the use of tDCS in the treatment of his depression. Again, I am not advocating the use of tDCS for the self-treatment of your depression. I’m simply collecting evidence, clinical and anecdotal, and making it available. That said, I know that if I myself were experiencing depression, I would be experimenting with tDCS. Especially in light of the fact that the efficacy of treatment of depression with SRRIs remains controversial, tDCS would definitely seem to be worth a try. [Highly recommended, Science VS podcast episode #11 Antidepressants.]
Featuring Swansea University researcher Claire J. Hanley @clairejhanley. Lucy Owen explores a new way of improving her memory. Will she score better at a memory test once her brain has been stimulated by electromagnetic impulses?
@DIYtDCS the montage used was position T7 (anode)/T8(cathode) from the 10-10 system
Market forces, the for-profit bias that imbues every aspect of health care in America, skew R&D towards solutions and products that are highly profitable. That’s one of the reasons I was so curious about tDCS. You can do it at home. It doesn’t cost a fortune. My initial curiosity was inspired by research papers that seemed to indicate the potential for cognitive enhancement, primarily memory and learning. Many papers later, I’m not so sure, but where it comes to tDCS and depression I’m much more confident. There does seem to be an overwhelming amount of both research and anecdotal evidence to support the use of tDCS in depression. If that were better known, perhaps someone like the woman featured in this NBC news clip would have had somewhere to turn when she was denied coverage for continuing TMS treatment for depression.