Looks like they use Transcranial Alternating Current Stimulation (tACS).
The military has been doing tDCS (direct current) experiments for a while for increased learning & performance.
I had a friend who used to swear by tDCS and did it very frequently. He attributed all kinds of mood & cognition improvements to it, including substantially reduced need for sleep, improved eyesight (he was born partially blind), etc. He also complained about migraines a lot and liked to experiment with all kinds of supplements, so YMMV.
Tried tDCS myself a handful of times, not for improved learning but for improved focus. If applied correctly it definitely has an effect that I'd consider better / stronger than a cup of coffee. I wouldn't feel comfortable doing it regularly though.
That reddit forum is full of "bro scientists" who use these methods are like hammers to bang the wetware without knowing how it works. Of course you get results when you mess with the system.
Reminds me of Alessandro Volta. In 1790, after inventing the battery, he stuck the the electrodes in his ears. He felt an explosion in his head, heard the sound of boiling “viscous matter" and passed out.
It would be nice if researchers could recruit these people to volunteer to be actual research subjects instead of messing with themselves and creating just anecdotes.
Some of the posts on that subreddit are seriously concerning. Burns on your head/arms seem to be common. One company in particular, "Foc.us", seems particularly dangerous.
Interesting tidbit: the foc.us manual says: "If you see white flashes (known as phosphenes), adjust the position of the foc.us headset away from your eyes"
Sorry, I've posted it on every tDCS article I've seen on HN, and no one has noticed it. It took three posts in this thread to get anyone to see it. I'm trying to help people be more cautious about their brain cells.
People keep posting tDCS articles without any warning about potential negative effects. There are a lot of young, impressionable people here who might experiment with what is put in front of them. I'd rather have people see the information and get myself downvoted in the process than keep watching articles like this get promoted without any warnings attached to them.
Interesting to consider if an unintended common cause of tACS is better encouraging lymphatic cleaning processes, especially where evidence is accumulating of the role of the dura mater.
By no means my area of expertise, but a quick glance suggests:
The experimenters set up a system that could detect slow-wave (SW) fluctuations in brain activity. They used trans-cranial magnetic stimulation (electro-magnets on the scalp) to "augment" this SW activity. This seems to have improved memory, measured by some specific learning task they set for the participants.
Trans-cranial magnetic stimulation is becoming popular in trans-human type circles. Apparently it's becoming feasible to do at home with cheap off the shelf components. However, of course, the long term effects and side effects are poorly understood.
This particular experiment used 16 participants (only three of whom were female, for some daft reason) so we can't draw any firm conclusions from this.
Apologies, you're quite right, they're using "transcranial alternating current stimulation" a.k.a. tACS during sleep. Now I'm at my desktop I can read the paper, and see that they applied direct current during task training (discovery of "hidden targets in static images") using the "StarStim R32 simultaneous EEG/Stimulation device", and their own tACS system during sleep.
ECT(Electroconvulsive therapy) is already a thing - it is used for various treatments for depression and seizures. It consists of small electric currents passing through the brain which is very similar to brain stimulation, the only difference is that he first one is a medical procedure while the latter is, as of now, more like a brain hack. I wouldn't recommend anyone doing it without knowing the risks involved.
I don't think it's accurate to describe ECT as using small electric currents. The very name says that the procedure induces convulsions.
From Wikipedia: "ECT is often used with informed consent as a last line of intervention for major depressive disorder, mania, and catatonia. ECT machines have been placed in the Class II category (special controls) by the United States Food and Drug Administration (FDA) since 1976." (Emphasis mine.)
The use a brain "massage" device on a person while they sleep and they see their longterm memory improving. Brain improvements are a big business and a lot of people have got ill for trying these stuff at home. https://www.bbc.com/news/health-27343047
Doing this stuff on yourself at home is pretty much an equivalent of trying to tune up your car's engine by randomly smacking it with a hammer while being blindfolded. You probably will not break it completely, but it's also very unlikely that it's possible to improve something without understanding how it works first...
Putting aside the fact that a lot of progress in history (herbs and medicines) have been found exactly this way, through trial and error and some 'mystic' guess work.
I don't think we are close to understanding the brain either.
And a lot more and focused progress have been made by people that study the subjects extensively, and try "things" and scientifically measure the impact.
from another website.. "tACS: Transcranial Alternating Current Stimulation (tACS) is a noninvasive, low-level alternating current applied to the cranium. New research out today suggests it expedites memory consolidation while you sleep. As with the above noninvasive transcranial stimulation techniques, it is not fully understood how it works and the long-term effects are unknown."
- https://www.forbes.com/sites/andreamorris/2018/07/23/can-we-...
I'm reading Why We Sleep (Matthew Walker), published 2017-09 - an HN recommendation from a while back - and I've just read the chapter where he describes an experiment that sounds exactly like this (as in, same approach, same outcomes).
Anecdote: I self-experimented with binaural beats some years ago. I did not notice anything regarding concentration, but I did find that tones starting in the normal awake/aware range and sliding linearly down to the slower, deep sleep range over 15-20 minutes would reliably cause me to fall asleep.
I ultimately layered that audio behind a guided meditation relaxation track I found online and used the combination as a sleep aid for a few years.
"Popular electric brain stimulation method used to boost brainpower is detrimental to IQ scores"
https://www.sciencedaily.com/releases/2015/05/150505152140.h...