Brain Biohacking

Brain electrical stimulation: Scientific research inspires biohackers

@enjoyman, Geektimes
For links to the works mentioned below, see the original article.

Over the past few years, scientific studies of electrical brain stimulation (tDCS) have demonstrated that it can improve many cognitive functions of healthy people: concentration, mathematical abilities, reaction speed. In total, more than 10,000 healthy volunteers have already participated in tDCS studies.

Following the scientists, biohackers – people who want to experience the results of scientific research for themselves - began to be interested in technology. In the USA, there is already a whole community that uses electricity to "pump" its brain. In addition, athletes are beginning to use tDCS, hoping that it can become a new and difficult to detect doping.

Scientific research

Briefly about the main thing. TDCS – transcranial direct current stimulation – came from medical research, where it is used in stroke recovery, for the treatment of depression, migraines and neurodegenerative diseases. At the moment, at least 224 clinical trials of this technology are taking place in the world. However, in the 2000s, studies began to appear demonstrating that tDCS can improve cognitive and motor functions in healthy people as well. Since that time, a great many articles have already been published, some of which were described on geektimes. However, even over the past year, the piggy bank has been replenished with several particularly interesting works:

No. 1. Speed up math learning and improve memory

In 2016, a group of scientists from Harvard, Oxford and the University of Tubingen found that tDCS accelerates learning and improves verbal memory by more than 20%, and the effect was long-term and persisted for 2 months.

The experiment involved 20 healthy volunteers who underwent electrical stimulation of the dorsolateral prefrontal cortex (DLPFC) – the area of the brain responsible for learning (including mathematical). In the experiment, there was also a control group of people in whom tDCS was imitated to exclude the placebo effect.

Electrical stimulation was performed with a current of 1 milliampere for 30 minutes a day for 2 consecutive days. And during the procedure, all participants of the experiment solved mathematical tasks. It turned out that 2 days after the start of the experiment, the subjects began to solve tasks with fewer errors and 9% faster than the control group. In addition, their verbal working memory improved by a quarter!

To assess the long-term effects of stimulation, 2 months after the end of the experiment, the scientists conducted tests again. It turned out that those who passed tDCS still showed much higher results. And, what is especially interesting, they solved tasks even faster than directly after tDCS. (After stimulation, the decision rate was 9% higher than that of the control group, and after 2 months – 20% more).

No. 2. Sleep less

In the same 2016, a group of German scientists led by Michael Nietzsche and Christoph Nissen demonstrated that using tDCS it is possible to reduce sleep time. Moreover, this is not accompanied by a decrease in the quality of sleep, nor by fatigue and drowsiness after waking up.

The 5-day experiment involved 19 healthy people, each of whom had electrical stimulation before going to bed. The effect was carried out on the neurons of the cortex, which are part of the cortico-thalamic pathway of sleep and wakefulness regulation. It turned out that tDCS reduced sleep time by an average of 25 minutes (compared to how much they also slept when simulating tDCS) and was accompanied by a long-term increase in activity of the cerebral cortex.

What is important, the quality and structure of sleep (phase ratio) did not change due to electrical stimulation, and the morning after the procedure, people felt no worse than usual.

No. 3. Increase concentration of attention

And in 2015, a study was conducted demonstrating that tDCS allows you to improve concentration.

During the mindfulness test, the subjects sat in front of a screen on which 5 arrows appeared, one above the other. Sometimes all the arrows were directed in one direction, and sometimes the central arrow had the opposite direction.

In a few hundred milliseconds, the subjects had to determine in which direction the central arrow was pointing and press the corresponding key. In some tasks, there was also a distracting signal in different areas of the screen.

It turned out that after electrostimulation of the parietal cortex, the volunteers responded faster (in the spatial attention task) than before tDCS. In the experiment, there was also a control group of people in whom tDCS was imitated. However, after the "fake" stimulation, the speed of the task did not change.

Electric doping?

In 2016, an article appeared in the journal Nature that tDCS improves endurance, muscle strength and coordination of movements in athletes.

Such a study was conducted by Californian developers from Halo Neuroscience in collaboration with the Ski and Snowboard Association of the USA. 7 professional athletes engaged in ski jumping participated in the experiment. Some of them were even on the U.S. Olympic team.

The athletes were divided into 2 groups: electrical stimulation was performed in 4 people, and simulated in 3 people. The experiment lasted 2 weeks, during which the athletes trained to perform jumps. And, as reported by Halo, electrical stimulation improved the strength of the jump by 70% (!) and coordination of movements by 80%, compared with the control group.

Another tDCS study in 2016 was conducted by scientists from the University of Kent. They found that electrical stimulation of the motor cortex suppresses the feeling of fatigue in athletes and increases endurance. The study involved 12 people who were also divided into 2 groups: some received neurostimulation, while others only thought they were getting it. Participants who were exposed to tDCS were willing to pedal for an average of two minutes longer and at the same time felt less exhausted.

All this is still only preliminary data obtained on very small samples of people, but the results are impressive. Many companies are already adopting them, starting to develop devices to improve the training of athletes.

How does it work? Mechanism of action

The main effect of tDCS on nerve tissue is considered to be the ability to cause "long–term potentiation" (LTP) and "long-term synapse depression" (LTD) - the processes underlying memory formation and learning. LTP is the rearrangement of contacts between neurons, leading to increased synaptic transmission. And LTD, on the contrary, leads to a decrease in the strength of synapses.

Now scientists identify several mechanisms by which tDCS can influence LTP and LTD, the most studied of which is the change in the membrane potential of neurons. A positively charged electrode ("anode") reduces the potential difference on the membranes of nerve cells, which leads to an increase in their excitability. A negatively charged electrode ("cathode"), on the contrary, increases the potential difference, reducing the probability of neuronal excitation when an external signal is received. Thus, electrostimulation by itself does not cause activation (excitation) of neurons, but changes their physiological state making them more or, conversely, less prone to arousal.

However, recently there have been studies showing that the mechanisms of action of tDCS are much more diverse. In 2016, an article was published in the journal Nature Communications that tDCS can affect neuroplasticity through the activation of auxiliary cells of nervous tissue – glial cells. In another study of the same year, tDCS was found to alter the epigenetic regulation of the Bdnf gene. This gene encodes a neurotrophic factor of the brain necessary for the formation of long-term memory. And under the influence of tDCS, cells began to produce a much larger amount of this factor.

To conduct tDCS, electrodes are placed on certain areas of the brain, depending on what effects need to be obtained. For example, to improve motor learning, an anode is placed above the primary motor cortex. The location of the electrodes is critically important for tDCS, as stimulation of different zones can lead to different results. TDCS allows you to locally increase the activity of the brain area over which the anode is located. However, now there are studies showing that the effect of tDCS is more widespread and affects some other areas of the brain that are functionally related to the stimulated area.

It is worth noting that the effectiveness of tDCS varies greatly for different cognitive functions. For example, the effect on motor learning and mathematical abilities is more significant than on working memory.

In most tDCS studies, a current of 1-2 milliamps is used for 20 minutes. In order for the effect of tDCS to be significant, it is necessary to conduct electrical stimulation for several days in a row. Single tDCS sessions are ineffective for most cognitive functions.

Brain biohacking – to spend at home?

The results of scientific research, as well as the simplicity of the tDCS procedure, attracted the attention of biohackers who began to conduct electrical stimulation on their own. In the USA, a community of people who are fond of "home tDCS" has already emerged, which, according to the estimates of the popular resource Reddit, includes at least 8000 people.

In June 2015, Stanford University conducted the first detailed study of this community: their age, gender, occupation and education, as well as the purposes for which they use tDCS.

It turned out that electrical stimulation is carried out mainly by men (94%) aged 20-30 years. However, there are cases of the use of tDCS by elderly people – to compensate for cognitive impairments in old age.

tDCS is mainly used by people with higher education (64%), 13% even have a PhD, MD or JD (Doctor of Law) degree. 11% of users have completed only 2 years of college, and 24% are school graduates or still studying there. Apparently, the point here is that people learn about tDCS mainly from tDCS research or tDCS-related sites (which also mainly describe scientific research), which introduces a certain educational qualification.

No correlation was found between the use of tDCS and the financial situation of people. Electrical stimulation is performed with approximately the same frequency (21%) by both low-income people with an annual income of up to $ 20,000, and fairly wealthy people earning more than $ 90,000 a year.

As for the scope of tDCS users' activities, they are mainly people engaged in professional activities and managers (37%), as well as students (20%). To a lesser extent, tDCS is used by officials (5%), office workers and people working in sales (4%), in the service sector (4%). 6% of tDCS users are unemployed.

tDCS are performed mainly to improve concentration, learning and memory. However, there is also a "medical" use of electrical stimulation – mainly from depression.

However, despite the fact that studies show the effectiveness of tDCS for some cognitive functions, as well as the sufficient safety of this method, scientists are rather reserved about initiatives of its home use and warn against using it. First of all, this is due to the fact that if the correctness of tDCS execution is strictly controlled in scientific laboratories, then biohackers can disregard safety rules.

So, for example, if you conduct tDCS for more than the prescribed 20 minutes, you can cause skin damage under the electrodes up to burns. In addition, undesirable effects can be obtained if the electrodes are carelessly positioned or the cathode and anode are swapped (in this case, you can even achieve a deterioration in cognitive function instead of improving it). In addition, it remains unknown how tDCS will work in the case of its long-term and regular use.

Nevertheless, the number of people willing to try the effect of electrical stimulation on themselves is only growing, and their experience can be easily read on the Internet. For example, journalist Sally Adi used tDCS during rifle shooting training:

"The 20 minutes I spent shooting at targets while the current was passing through my brain were wonderful. I only remember that I felt as if I had drunk a mug of the finest coffee, but without any "coffee nervousness". I had an absolutely clear head, I was no different from my usual self, but I was more collected. And calmer. I had no fear, no doubts. From that time on, it was as if I was just waiting for a new task to appear in order to complete it. Having got rid of my inherent fear and self-doubt, I turned into a damn cool shooter. You can't even imagine how amazing it was to find out how much these feelings prevent me from performing everyday tasks, and indeed from living at all."

Opinion polls also show that impressions of electrical stimulation are generally positive. Almost half (44%) rate their experience as "successful" and "very successful". Approximately 41% rate the effect of tDCS as "average" and 14% as "unsuccessful".

However, it should be borne in mind that in the case of individual use of tDCS, the placebo effect is not excluded. In addition, it is difficult to separate the improvement of cognitive function, which occurs simply due to repeated task completion, and due to electrical stimulation.

On the other hand, a survey of tDCS users shows that many of them experience side effects. Basically, it is burning and itching in the area of electrode attachment. Sometimes, when using tDCS, headache, nervousness and fatigue may occur, although it is rated as "very weak".

To achieve a quantitative assessment of changes in cognitive performance, tDCS users often use so–called brain simulators - "Lumosity", "Dual N-Back Game" or "Cambridge Brain Challenge". A story about testing tDCS, including while playing Lumosity, was written by neuroscientist Nikolai Kukushkin:

"... The most interesting thing happened when I started experimenting with the places where the electrodes were attached. The American military is stimulated not by the forehead, but by the right temple. When I tried this configuration, the difference became obvious. Not that goosebumps ran through the body, but a kind of soft, warm shiver – it happens when you plunge into some process with your head and see nothing but this process. I took up Lumosity again. Memory did not stand out much, attention improved slightly. But when I tried speed games, there were no questions left.

In these games, you need to quickly make a simple decision, for example, whether the card shown matches the previous one. Yes – one key, no – the other. We need to react as quickly as possible and avoid mistakes. The first time I broke three records in three different games organized according to this principle. In all three cases, the previous records were several months old. It took me a few seconds to "join" the game, after which my fingers seemed to drum themselves, and the same tremor spread through my body. I wanted to laugh..."

In general, it is not difficult to conduct tDCS at home. Many companies have started producing compact tDCS devices, for example, "focus", "thync" and "the braintimulator" in the USA. The wave of "DIY" electrical stimulation is beginning to reach Russia, at least the first Russian tDCS device is at the stage of successful crowdfunding.

However, it is worth bearing in mind that tDCS is still an experimental technology, the long–term and ethical consequences of which have not been fully studied. And in the case of use – it requires a very careful attitude and careful observance of all the rules of application.

Portal "Eternal youth" http://vechnayamolodost.ru  15.07.2016