Our friend and trusted neuroscience PHD student Nathan just published a review of the new LIFTiD tDCS device, A Look At The LIFTiD tDCS (Full disclosure, both he and I were given one to try out by Caputron. I’ve been waiting for Nathan’s report before trying mine.)
The obvious advantage to the LIFTiD device is it’s simplicity and ease of use. As I suspected this also turns out to be it’s main weakness in that you have only the default montage available.
The LIFTiD team was advised by neurosurgeon Dr. Theodore H. Schwartz. He was recently interviewed by Neurogal MD. While much of what is discussed will be familiar to DIYtDCS readers, I was interested to see that Dr. Schwartz was quick to point out what we don’t know about tDCS and neurostimulation.
I was happy to lend Nathan my Thync. I knew he’d get to the bottom of what exactly was going on. Especially in the context of exploring TES, pulsed wave forms and some of the older technologies I’d recently been made aware of in my interview with Anna Wexler, I knew the Thync device would represent the state of the art. Jamie Tyler had arranged for me to have one, most likely in my capacity as a blogger and reporter of all things related to neurostimulation. I myself did not experience any significant effects using the Thync though I did find myself using it frequently – mostly the Calm vibe. Was there some effect lying just below consciousness that my body was reacting to? Certainly nothing like the experience Manoush Zomorodi had trying Thync for her podcast episode Forget Edibles: Getting High on Wearables (really a must hear).
A while ago, I was asked by the makers of TheBrainDriver to write a review of the device. Being curious about this device myself, I got a review unit…and promptly forgot about it for a while while I flew around the country for interviews. But now that that’s mostly done, I’d like to share my impressions on this device!
This is very, very different from the montages that have been used in studies of cognitive enhancement in the past (and the most common ones used by the DIY community), which typically use an anode placed near some site on the prefrontal cortex and another either placed on the same region on the other side of the head, above the eye on the other side of the head, or somewhere on the contralateral body below the neck (to generate a montage with only one site with high current density). The authors explain why they wanted to stimulate both sides simultaneously (complex tasks engage large regions of the frontal cortex, therefore they thought stimulating a large area would be desirable. Oddly, they even mention the more conventional way of doing this (an F3-F4 montage), but never explain why they decided against it.
Nathan Whitmore just launched a tDCS search engine!
The goal of Montage Explorer is slightly different from that of a traditional montage website. While most of these sites attempt to provide details one a montage used in one or two studies, the goal of Montage Explorer is to provide an aggregate view and summary of all the research on a particular montage (including side effects that are discovered in studies by other authors and “null results” where an effect fails to replicate) and provide access to the original results and publications, using automated analysis of articles published on noninvasive brain stimulation.
Fantastic to have a resource in the community like Nathan who has the background and technical expertise to do a deep dive into assessing a device like the new Foc.us v2. The entire review is a must read but here I’m quoting his analysis of the safety issues.
The foc.us also includes some new safety features designed to reduce the risk of high-current-density induced injuries. The most interesting is a soft voltage limit; while the device can technically output voltages out to 60V, users can specify a lower limit to not exceed. This provides protection if the connection between electrodes and the head starts to fail (due to electrode drying or drift, for instance); rather than increase voltage to the absolute maximum in an attempt to drive the target current over the failing connection (which can result in very high current density through a small patch of skin), the device can be configured to simply allow the current to drop using this limit. Unfortunately, there’s no actual alert that the connection is failing (although this can be deduced from looking at the current monitor during operation) but this still provides a good way to avoid many of the safety issues that the high maximum operating voltage would otherwise entail.
Another important area of safety is the ability of the current regulator to maintain its specified current and voltage outputs under varying conditions. Here I tested the device under two conditions: with relatively stable impedance at varying levels (simulating a typical use case in a person sitting still) and in an “impulse” condition, where impedance changes instantly from very high to very low or vice versa. The purpose of this testing method is to measure the device’s response to temporary very sharp changes in impedance caused by disconnection and reconnection of the electrodes as might occur in the Edge device when used during athletic performance.
Here the foc.us performed perfectly; neither current nor voltage ever significantly exceeded their specified maximums under varying conditions. The response to impulses was particularly impressive, with no significant “overshoot” even at the maximum voltage output.
Second, there’s an emerging picture of how different forms of electric brain stimulation like tDCS, tACS, and tRNS work. An emerging consensus among both mechanistic and clinical researchers seems to be that the major effect of tDCS (and to a lesser extent tRNS) is to boost plasticity in stimulated regions while tACS exhibits weak to nonexistent effects on plasticity but provides a means to interact with ongoing brain rhythms. Secondly, there’s increasing acknowledgement that even when the spatial current spread is restricted; stimulation induces very significant “network effects” through feed-forwward and feedback connections between brain regions; these effects (as well as individual variability) might explain why observing consistent physiological effects of tDCS is difficult. Finally, an increasingly popular area of interest seems to be combining tDCS with some kind of cognitive training or exercise, based on the hypothesis that tDCS-induced plasticity enhancement will be synergistic with these regiments.
You’re more likely to know Nathan Whitmore as /u/ohsnapitsnathan, one of the moderators at the tDCS subReddit. Around making plans to attend NYC Neuromodulation Conference 2015, he’s started a GoFundMe campaign and announced an early Beta of his tDCS device, BrainKit. It’s a very ambitious project! He plans to include sensors that would monitor brain activity using capacitance (Electrical Capacitance Volume Tomography)! The BrainKit would then generate optimal montages for specific desired effects! It’s Arduino based, and Nathan intends for it to be Open Source. It’s very early in the BrainKit’s development, but it appears to me that all the pieces are in place.
A feature new to BrainKit is the ability to act on this information by designing a montage. BrainKit’s montage designing algorithm is actually quite simple, and based on the principles that:
1. If increased performance on a psychometric measure is associated with higher excitability in a cortical area, BrainKit will deliver anodal stimulation to that area, if decreased excitability is associated with increased performance then BrainKit will use cathodal stimulation.
2. If functional connectivity between two electrodes is positively associated with good performance, anodal stimulation is delivered to both electrodes, if it is negatively associated with good performance then cathodal stimulation is applied to both electrodes.
3. If any electrode conflicts exist the previous two rules cause one electrodes to be marked for both anodal and cathodal stimulation, that electrode is excluded from the montage.
Hi! I’m Nathan Whitmore, AKA /u/ohsnapitsnathan . I design open-source, DIY brain stimulators OpenStim and BrainKit and I moderate Reddit’s brain stimulator forum. I’m raising money to go to the New York Neuromodulation conference this January and talk about open-source brain stimulators and the DIY community!
WHY: While I currently work in a research lab studying how the brain controls attention, I’m really a tDCS DIYer at heart—I built my first tDCS unit two years ago, when I was in college, and started working on OpenStim a few months later. What these experiences made me aware of is that there’s a large and growing communication gap between people who research tDCS, and the vast majority of those who actually use it. That’s bad for everyone, because it means that what we research and what we actually care about start to diverge.
Depending on where he puts the electrodes, Whitmore says, he has expanded his memory, improved his math skills and solved previously intractable problems. The 22-year-old, a researcher in a National Institute on Aging neuroscience lab in Baltimore, writes computer programs in his spare time. When he attaches an electrode to a spot on his forehead, his brain goes into a “flow state,” he says, where tricky coding solutions appear effortlessly. “It’s like the computer is programming itself.”
Whitmore no longer asks a friend to keep him company while he plugs in, but he is far from alone. The movement to use electricity to change the brain, while still relatively fringe, appears to be growing, as evidenced by a steady increase in active participants in an online brain-hacking message board that Whitmore moderates. This do-it-yourself community, some of whom make their own devices, includes people who want to get better test scores or crush the competition in video games as well as people struggling with depression and chronic pain, Whitmore says.
Jesse interviews Nathan Whitmore, creator of the open-source project OpenBrainStim, an affordable alternative to commercial transcranial Direct Current Stimulation (tDCS) devices. Nathan tells us how the project got started, how the “DIY-tCDS” community has grown, and how you can experiment from the comfort of your own home.