You may have noticed that I’ve not been posting as much to the blog lately. The blog is already so full of useful content for anyone looking into tDCS that I’m inclined to only post significant information that would move our current understanding of tDCS and neurostimulation forward. This article/paper describing a new technique using ‘HD tACS’ to synchronize (brainwaves) parts of the brain definitely looks intriguing and has implications for anyone paying attention to DIY neurostimulation. Very early, but very interesting.
Prof Rob Reinhart. Photo by Cydney Scott for Boston University Photography
“These (medial frontal cortex & lateral prefrontal cortex) are maybe the two most fundamental brain areas involved with executive function and self-control,” says Reinhart, who used a new technique called high-definition transcranial alternating current stimulation (HD-tACS) to stimulate these two regions with electrodes placed on a participant’s scalp. Using this new technology, he found that improving the synchronization of brain waves, or oscillations, between these two regions enhanced their communication with each other, allowing participants to perform better on laboratory tasks related to learning and self-control. Conversely, de-synchronizing or disrupting the timing of the brain waves in these regions impaired participants’ ability to learn and control their behavior, an effect that Reinhart could quickly fix by changing how he delivered the electrical stimulation. The work, published October 9, 2017, in the journal Proceedings of the National Academy of Sciences (PNAS), suggests that electrical stimulation can quickly—and reversibly—increase or decrease executive function in healthy people and change their behavior.
Here’s the paper (paywall): Disruption and rescue of interareal theta phase coupling and adaptive behavior. The supplemental pdf. describes the equipment used in the experiment.
High definition transcranial alternating current stimulation ( HD- tACS ). The alternating current stimulation was administered noninvasively using an MxN9-3 channel high definition transcranial electrical current stimulator from Soterix Medical (New York, NY). Eight sintered Ag/AgCl electrodes were attached to high-definition plastic holders, filled with conductive gel, and embedded in the Biosemi EEG cap. HD-tACS electrode placement was guided by current-flow modeling using HD- Explore and HD-Targets (Soterix Medical), with the goal of targeting the MFC and lPFC to facilitate the synchronization of neural activity between these regions (the in phase protocol ) or disrupt the signals being conveyed between the MFC and lPFC (the antiphase protocol ).
Listen to Bob McDonald discuss HD tACS with Prof Rob Reinhart on the always interesting Quirks and Quarks.
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
Neuroscience doctoral student Bashar W. Badran is exploring the Use of tDCS to enhance Mindfulness Meditation (E-Meditation) MUSC Research Assistant Caroline Summer is in background, demonstrating the tDCS device. Photo by Sarah Pack
Badran, who used two different mindfulness scales and mood rating scales on 15 participants in a double-blind study, found that feelings of calmness increased almost 2.5 times in the group receiving active tDCS-paired meditation compared to the placebo. Individuals receiving the sham stimulation had just a 5 percent increase in calmness rating.
In South Korea, Ybrain is betting that these benefits and its slick consumer-friendly design will speed adoption of its device. “It’s designed for home use,” says Ybrain CEO Lee, “so physician can electronically prescribe the device and patients can bring it to their homes.”
Analysing these high-standard studies revealed that tDCS seems to reliably improve the symptoms of depression, addiction and craving, and fibromyalgia. It also uncovered that the technique does not work for tinnitus, and that the evidence for using tDCS for stroke rehabilitation was not as strong as many had thought.
Although the home use of tDCS is often referred to as a novel phenomenon, in reality the late nineteenth and early twentieth century saw a proliferation of electrical stimulation devices for home use.
In particular, the use of a portable electrotherapy device known as the “medical battery” bears a number of striking similarities to the modern-day use of tDCS.
Many features related to the home use tDCS—a do-it-yourself movement, anti-medical establishment themes, conflicts between lay and professional usage—are a repetition of themes that occurred a century ago with regard to the medical battery.
A number of features seem to be unique to the present, such as the dominant discourse about risk and safety, the division between cranial and non-cranial stimulation, and utilization for cognitive enhancement purposes.
Viewed in historical context, the contemporary use of electrical stimulation at home is not unusual, but rather the latest wave in a series of ongoing attempts by lay individuals to utilize electricity for therapeutic purposes.
An email from Michelle Pearson at the NIH (because I had signed up for the online version of the workshop) alerted me today to a trove of TES (Transcranial Electric Stimulation) info being made available to us. Presenter slides (in PDF form) from the workshop were available for download. Because the download process was pretty wonky, involving many clicks and declined logins to Dropbox I thought to make them available here as well.
We developed a cellular brain stimulation device as part of our ELEC5622 Sensors, Signals & Health assessment at the University of Sydney. The technique, known as transcranial direct current stimulation (tDCS), uses weak electrical currents to modulate ongoing brain activity, and is a promising treatment for a range of neurological and psychiatric diseases. As the feasibility of administering tDCS at home has recently become an emerging area of research, there is a substantial need for a tDCS device which send data to the clinician in real time.
[Update 11/7/16 The video mentioned has been deleted.]
Unlike commercial brain training products, which only improve performance on the skills involved, musical training has what psychologists refer to as transfer effects – in other words, learning to play a musical instrument seems to have a far broader effect on the brain and mental function, and improves other abilities that are seemingly unrelated.
“Music reaches parts of the brain that other things can’t,” says Loveday. “It’s a strong cognitive stimulus that grows the brain in a way that nothing else does, and the evidence that musical training enhances things like working memory and language is very robust.”
Now that TMS has been approved for the treatment of depression we’re seeing a lot more stories in the news. Naturally this is in part due to the marketing efforts of the four device makers currently FDA approved: Brainsway, Magstim, Magvita, and Neurostar. No doubt patients and doctors are eager to try an alternative where antidepressants didn’t work!
I will update this post as I find new and interesting news stories related to TMS and depression.
Fidel Vila-Rodriguez, an Assistant Professor of Psychiatry at the University of British Columbia, is exploring the effects of transcranial direct current stimulation combined with yoga, to see if it can be used to treat depression.
To help with electrode positioning we have updated a 3d model head with the 10/20 electrode placements. Click the position name e.g. F3, and it will appear on the head. You will still need to translate this to your own head but we hope it helps. (Move the model around with your mouse.)
We are also now selling a version of Go Flow Pro that includes our 1020 position cap instead of the headband. It includes everything you need to get started.
Eliza Strickland covered the HaloNeuro tDCS device. This clip shares my hopes about the Halo… that sports serves as a gateway until they can get established. IMO we need a device manufacturer with deep pockets who can satisfy the research and regulation requirements to make tDCS (or any other form of Non-Invasive Brain Stimulation – NIBS, that is effective) mainstream.
While the authorities dither, Halo will do its best to slip into the mainstream. And athletes are just the first customers targeted by this ambitious company. In South Carolina, a neurologist is currently testing the Halo with stroke patients to see if stimulating the motor cortex speeds up rehab. Chao envisions a whole range of Halo products offering consumers different kinds of mental boosts. “What if you want to learn Chinese and we stimulate the language center?” he says. “What if we stimulate the memory center and pair that with brain-training games?”