Excellent! A full hour with Dr. Wesiend. Haven’t listened yet but guaranteed to be the latest info in our understanding of tDCS. We met Dr. Weisend earlier in podcast #4,
Recently, transcranial direct current stimulation (tDCS) or the non-invasive targeting of weak direct current (DC) to specific brain regions has received media attention. Among the scientific research community, tDCS has been a subject of great interest owing to its usage ease, relative inexpensiveness, and encouraging research results on a range of functions. Studies have seen tDCS accelerate learning, reduce symptoms of dementia, and improve attention in those with Attention Deficit Disorder (ADD). Understandably, a coinciding rise in the DIY community has also prompted an increase in consumer devices available for home use in hopes of mimicking tDCS’s potential neuroenhancement abilities.
Scarce on details but certainly I will be keeping tabs on this.
Deep sleep, a period that’s known as vital for memory formation, becomes rarer as people age, waning more and more after individuals hit their mid-30s. By attaching two electrodes to a person’s scalp, Walker can direct a current into the prefrontal area and simulate the slow waves of deep sleep while the wearer slumbers.
The technique is called transcranial direct-current stimulation (tDCS), and while the equipment to do it is commercially available, it is not FDA approved for use on medical conditions. The devices in their current form aren’t intelligent enough to know when a wearer is in deep non-rapid eye movement (NREM) sleep, and so they aren’t able to start stimulating in that sleep stage on their own and sync up with the brain’s waves. “At present, we scientists need to do this in a sleep lab,” says Walker. “We have to measure someone’s sleep, and then switch the stimulator on at the desired stimulating rhythm to have a beneficial effect.” That said, he believes in five to eight years these issues will be resolved, and these devices could help those with Alzheimer’s, dementia, insomnia, depression and anxiety.
Sham or anodal tDCS (1 mA) was applied for 20 min during motor practice and retention was tested 30 min, 24 hours and one week later. All subjects improved performance during each of the two sessions and learning gains were similar. Our main result is that long term retention performance (i.e. 1 week after practice) was significantly better when practice was performed with anodal tDCS than with sham tDCS. This effect was large and all but one subject followed the group trend. Our data strongly suggest that anodal tDCS facilitates long-term memory formation reflecting use-dependent plasticity. Our results support the notion that anodal tDCS facilitates synaptic plasticity mediated by an LTP-like (long-term potentiation) mechanism, which is in accordance with previous research.
Is it safe? Obviously the test wasn’t designed to assess any possible negative cognitive effects, but apart from some, “skin tingling, itching, and mild burning sensations” the subjects tolerated frequent TES (transcranial electric stimulation) well.
In the present study, we tested the tolerability (safety) and compliance, compared to sham, of two common tES approaches having a current density < 2 mA/cm2; transcranial Direct Current Stimulation (tDCS) or transcranial Pulsed Current Stimulation (tPCS) used by healthy subjects three to five days (17 – 20 minutes per day) per week for up to six weeks in a naturalistic environment. In this study 100 healthy subjects were randomized to one of three treatment groups: tDCS (n = 33), tPCS (n = 30), or sham (n = 37) and blinded to the treatment condition. The tES and sham waveforms were delivered through self-adhering electrodes on the right lateral forehead and back of the neck. We conducted 1905 treatment sessions (636 sham, 623 tDCS, and 646 tPCS sessions) on study volunteers over a six-week period. There were no serious adverse events in any treatment condition.
tDCS modified moral behavior! By ‘utilitarian’ I believe the researchers mean that the subject was less likely to ‘save the many’ by (actively participating in) sacrificing the few.
Accordingly, during anodal stimulation of the left DLPFC participants rated the utilitarian actions as more inappropriate than they did during sham and cathodal stimulation. Thus, anodal tDCS of the left DLPFC resulted in a shift of preference from an utilitarian, active decisions (i.e. to actively hazard another person’s life to rescue the lives of several people) to non-utilitarian, passive decisions (i.e. to avoid harming another person, but in consequence to accept the harm to several people.
For context, you might want to examine The Trolley Problem!
So where is the clever researcher who will tap into Foc.us and their API to bring hundreds (thousands?) of Foc.us users into online study mode. What an opportunity to pioneer citizen science meets legit scientific research.
foc.us for research
Open standards, API and requests accepted
Foc.us v2 has all of the features found in your commercial research kit. You can run larger studies with more participants at lower cost. This includes double blind sham mode. Logging of all sessions at 50ms intervals. Set maximum current, maximum voltage, ramp up time and everyhing else.
If you have a custom request – triangle waves, custom patterns – we will code it if we can.
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.
** PANEL **
Hank Greely, JD, Director of the Center for Law and the Biosciences at Stanford Law School.
Alvaro Pascual-Leone, MD PhD, Director of the Berenson-Allen Center for Noninvasive Brain Stimulation at Beth Israel Deaconess Medical Center.
Jamie Tyler, PhD, the CSO at Thync, a company that manufactures noninvasive brain stimulation technologies for a consumer market.
Hey, we’re mentioned in a legit scientific journal! The article traces the evolution of tDCS in the public’s consciousness, and points out how sites like my own and the tDCS subReddit serve a valuable function in filtering information as presented in the general media, which often has a tendency to sensationalize soundbite takeaways from legit scientific papers. So chalk one up for citizen science and let’s hope this is a step along the way towards legit research that taps into the DIY communities. i.e. University-level research that creates methodologies for using DIY generated data.
The availability of tDCS as a consumer device, as well as the vivid online exchange of experiences with tDCS as well as instructions for DIY use (cf.: http://www.reddit.com/r/tDCS/; http://www.diytdcs.com) may be explanatory factors shaping the change in public attitudes towards tDCS, The observation that in the LATER PERIOD misunderstanding was reduced can be regarded as evidence that the public was developing a more mature understanding of tDCS. In view of the past trends, it appears important to inform the public accurately on the short- and long-term consequences of tDCS on healthy individuals and on the plausibility of enhancement effects. In addition, detailed knowledge of the current practice and prevalence of DIY tDCS is also needed.
This is what the media does! They are referencing the article discussed here, where Nathan Whitmore (ohsnapitsnathan) points out that due to the unusual electrode configuration, “…the current density at the cathode is actually greater than at the “active” electrodes…).
Who ever thought this was a good idea? A form of electrical brain stimulation was first used to treat melancholy in the 19th century.
Melancholy isn’t even a thing. In the 1960s, tDCS became briefly fashionable when it was shown that it could alter the excitability of neurons in the motor cortex. More recently, it’s been used to increase or decrease cortical activity with the aim of alleviating depression or insomnia.
Hopefully, doctors will exercise extreme caution with the treatment now the possibility of detrimental effects has been raised. Are you kidding? People are out there zapping themselves – you can buy a tDCS kit online for less than £100. You can even find instructions to make your own.
So this isn’t the end for tDCS? Probably not. And a similar application, but with alternating current – tACS – is also being researched.
Do say: “The effect of electrical stimulation on the brain has fascinated scientists for centuries, and yet it remains so little understood.”
Thync’s strategy is to bypass the brain and instead use pulsed currents to stimulate peripheral nerves closer to the surface of the skin, with the goal of modulating the user’s stress response.
“We spent a year and a half optimizing the wave forms to the point that we felt really confident in the science,” said Jamie Tyler, the company’s chief science officer. His team has tested about 3,300 people in single-blind and double-blind, placebo-controlled studies.
Wave forms refer to a series of electric pulses that change frequency and amplitude over time. Like a sound equalizer, the theory goes, the parameters can be “tuned” to produce an intended biological effect.
Soon into my 20-minute demonstration, I feel a sharp, slightly painful tingling above my eye, like vibrating pinpricks. I brace myself, awaiting relaxation.
According to Dr. Tyler, the “calm vibe” at its peak produces a relaxation greater than that provided by three Benadryls, according to a common statistical measure for effect size. The “energy vibe” is said to be stronger than that produced by a 20-ounce can of Red Bull. Each mood lasts for about 45 minutes without a subsequent crash, Thync says.
But some experts are skeptical, insisting that the company show evidence of peer-reviewed, independently replicated results.
[Update 5/15/15 More or less debunked, at least a much better understanding of the anomalies of this particular study, from Nathan Whitmore’s rebuttal.] Would only now like to see this replicated with tDCS applied during testing. i.e. In this study tDCS was administered prior to the test (‘offline’ as opposed to ‘online’). But for those of us who are looking to tDCS for potential cognitive enhancement, this is a significant study. Posted to Reddit by Gwern!
Transcranial direct current stimulation (tDCS) modulates excitability of motor cortex. However, there is conflicting evidence about the efficacy of this non-invasive brain stimulation modality to modulate performance on cognitive tasks. Previous work has tested the effect of tDCS on specific facets of cognition and executive processing. However, no randomized, double-blind, sham-controlled study has looked at the effects of tDCS on a comprehensive battery of cognitive processes. The objective of this study was to test if tDCS had an effect on performance on a comprehensive assay of cognitive processes, a standardized intelligence quotient (IQ) test. The study consisted of two substudies and followed a double-blind, between-subjects, sham-controlled design. In total, 41 healthy adult participants completed the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) as a baseline measure. At least one week later, participants in substudy 1 received either bilateral tDCS (anodes over both F4 and F3, cathode over Cz, 2mA at each anode for 20 minutes) or active sham tDCS (2mA for 40 seconds), and participants in substudy 2 received either right or left tDCS (anode over either F4 or F3, cathode over Cz, 2mA for 20 minutes). In both studies, the WAIS-IV was immediately administered following stimulation to assess for performance differences induced by bilateral and unilateral tDCS. Compared to sham stimulation, right, left, and bilateral tDCS reduced improvement between sessions on Full Scale IQ and the Perceptual Reasoning Index. This demonstration that frontal tDCS selectively degraded improvement on specific metrics of the WAIS-IV raises important questions about the often proposed role of tDCS in cognitive enhancement.
Maiques compares Neuroelectrics to the “DIY” ethos of health-tracking technology, such as Fitbit and other wearables. “We have an ageing population dealing with chronic illnesses, but people are also becoming more self-aware when it comes to monitoring their health. We believe these self-monitoring technologies are going to become popular in the home over the next few years.”
Not tDCS. It looks like TMS (Transcranial Magnetic Stimulation) but I’ve not heard of TMS being applied for more than short bursts before. Also of note in the article is the description of their target:
Their training programme targets the brain’s ‘dorsal attention network’, which links regions of the prefrontal cortex – the bit of the brain above the eyes that helps us make decisions – and the parietal cortex, the ‘switchboard’ for our senses, which is above and slightly behind the ears.
(Caroline Williams)The pulses were aimed at my left prefrontal lobe, to dampen the activity there (Caroline Williams)When I get to the stimulation the next day, it’s not as bad as I feared. At least not at first. For the first minute or so it feels a bit like popping candy is going off under my skull. Five minutes in, though, and it’s seriously annoying – like the worst school bully ever repeatedly flicking me on the head.In all, I have two eight-minute-long sessions of magnetic stimulation, each followed by a 12-minute-long session of computer-based training. I also do three 12-minute blocks of training twice a day, over the internet, wherever my laptop and I happen to be.
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.