Vagus Nerve Stimulation has been on my radar for some time but recent developments, especially in our understanding of the Brain-Gut connection have me paying more attention to what’s happening in VNS research. This post will serve as a simple introduction in hopes of inspiring your own curiosity and I’ll fill in the blanks as more information becomes available. Overview from Wikipedia: Vagus Nerve Stimulation.
And finally a couple of device manufacturers with products currently on the market. I have zero relation to any of these companies and am linking to them simply so you can see what the devices look like and how they are marketed. There are probably many more. gammaCore NEMOS Monarch
“Older people’s memory got better up to the level that we could no longer tell them apart from younger people,” said lead investigator Joel Voss, associate professor at Northwestern University Feinberg School of Medicine. “They got substantially better.”
Not related directly with the research, but interesting to note in the video where Canadian researcher Jed Meltzer, a scientist at Baycrest Hospital’s Rotman Research Institute in Toronto is shown demonstrating an ActivaDose device and an unusual montage.
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.
“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.
[Update 3/18/19] Exciting news in the fight against Alzheimer’s! Dr. Tsai has a new lab. Tsai Laboratory
In the new study, researchers added acoustic stimulation that pulsed at the same frequency as the visual stimulation. And when mice — which were bred to develop Alzheimer’s-like symptoms — were exposed to both, researchers saw that the neurons in several of their brains’ key memory circuits chimed in and began humming along at exactly the same frequency. What came next was remarkable and unexpected, even to the authors of the study. In the wake of the sound and light sessions, an army of newly energized immune cells descended on several areas of the treated brains, including those most affected by dementia. Then they set to work with a vengeance on some neglected housecleaning.
LA Times https://www.latimes.com/science/sciencenow/la-sci-sn-alzheimers-brain-waves-20190315-story.html
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…
This tweet, posted August 3, 2018, reminded me of Bashar W. Badran’s study (story below from 2017). Following along in the links I see that Badran has been testing a new ‘e-meditation’ device called Zendo. It’s currently not available to the general public, but you can see it in action in the photos below the tweet. You can sign up to be notified when the device becomes available here: https://e-meditation.com/about
Supercharge your zen (pdf) The benefits of yoga and meditation are plentiful, but they take years of dedicated practice to achieve. Could a zap to the brain offer a shortcut?
I had previously posted this in a comment. Sourced from the original study.
Each 20min E- meditation visit consisted of one of three randomized stimulation conditions (sham, active 1mA, or 2mA; anode – EEG F8, cathode – left supraorbital) delivered via a Chatanooga IontoTM stimulator and 2in x 2in sponge electrodes. Stimulation was synchronized with a guided mindfulness recording (recorded by ELG) lasting 20min.
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.
We’ve met Adam Gazzaley elsewhere on the blog, but probably because he and Rob Reid have a friendship spanning years, this is a very friendly and thorough discussion of all Adam is up to. Reid has a new book (fiction, sci-fi) called After On, and Gazzaley was called on to provide insights into a few of the book’s key concepts related to consciousness and neuroscience.
There has been a lot of talk in the literature lately about tACS as it applies to cognitive enhancement and this is explored in the conversation. If I got this right… there is a distinct pattern of ‘Midline Frontal Theta’ frequency, at around 6Hz (as measured by EEG) associated with ‘focus’ (as measured by fMRI) in the Pre Frontal Cortex. This begs the question as to whether focus could be generated by using tACS to ‘entrain’ the PFC (as in… induce 6Hz Theta in the PFC using tACS). Again I will remind the reader that I am not a scientist!
Gazzaley also brings us up to speed on the clinical trial for FDA clearance of EVO, his video game/therapeutic that Akili has developed for kids with ADHD.
The episode is embedded here, but swing over to https://after-on.com/episodes/002 to read the show notes and to learn more about Rob Reid. He has a number of fascinating interviews with other guests in his podcast and brings a lot to the table himself considering a long career both as a technologist, investor and author.
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.