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Comment by PaulKeeble | Hacker News Reader

There have been a couple of papers [1] that can induce this process while awake using particular image patterns as confirmed in an MRI. I think the NIH confirmation is running behind in the science, independent research is quite a bit ahead of them. I came across the paper on this last year and implemented a very simple page with the parameters they used [2].

There is a number of disease models that show reduced or no glymphatic clearance and as such these people need treatments to clear out their brains and these image routines seem to help. A lot of people find this pattern extremely taxing to watch especially for the recommended number of cycles, you can feel the effect on the brain its hard to describe the sensation its a bit numbing and the image has the sensation of changing as the cycle runs like its a visual trick. You might get left feeling like you have been clubbed over the head the first time.

I find it interesting this is one aspect of disease research I am looking into and is related to Long Covid and ME/CFS.

[1] https://journals.plos.org/plosbiology/article?id=10.1371/jou...

[2] https://www.paulkeeble.co.uk/posts/cff/

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Paul's animation wasn't playing at an even rate for me, for some reason, so I created two video versions (8Hz and 12Hz) with the 16 second on/off period, starting with an off period, running for 254 seconds, as per the paper. These versions end with an an additional off period, as a 'cool down' from the flicker.

Framerate of 24Hz differs from the 120Hz as presented in the paper, but here there is no 40Hz flicker attempt so it shouldn't be an issue.

Compression may affect the edges of the lines, but downloads are enabled.

8Hz version - https://vimeo.com/1023278230/8ad6db6234

12Hz version - https://vimeo.com/1023275135/378186db55

What is the difference or use cases for 8Hz vs. 12Hz?

My understanding from the paper is there is no difference between 4, 8, 12, and 40Hz frequencies on the neurobiologcial effects, but I found the 8Hz a bit less comfortable than the 12, so I uploaded both.

Do these need to be full screen with your face close to the screen to fill my field of vision, or would it work just as well watching it in a smaller window, on an iPad or even on a phone?

I stared at the 8hz one, for the entire duration, and I feel a calm afterward, however I'm not sure if this is because I stopped doing/thinking for a few minutes with measured breathing or if it is me noticing the difference now that there's a lack of stimuli after the video ends.

What measurements or tests can I do to judge whether something is happening, or has happened after watching the videos?

The idea that watching a video triggers some waste clearing mechanism is pretty wild.

Makes me think of Neal Stephenson's Snow Crash where a datafile can be a narcotic or mind virus. Maybe that's not such a crazy idea?

> The idea that watching a video triggers some waste clearing mechanism is pretty wild.

It kind of makes sense. We can look at images of food and get a physical reaction like hunger, or look at macabre images and feel disgust, or stare at animations for one minute and then be affected for many minutes afterwards when we look away.

It doesn't surprise me we're still discovering new mechanisms for triggering physical reactions in our bodies.

Edit: I do agree it's pretty wild regardless :) Especially wild if we're finally discovering mechanisms that have useful effects, not just "fun" effects like visual distortion.

Not wild at all. think of brain cancer (AKA GBM AKA glioblastoms multiforme).

The more you think, the more blood to the brain, the faster the cancer grows.

Think about it.

You can also watch a video that will add waste to your brain.

Would be interesting to find out if there could be an desired effect of this in conjunction with binaural beats.

Wow! So a visual effect similar to some psychadelic hallucinations is associated with brain cleaning!

Also, I've been at concerts where the light show guy seems to have reverse-engineered the filters our brains use to process raw signal into "images", and could use the lights to create just the raw primitives.

A few hours of that and it was like I was learning to see all over again, a tune-up/calibration of my visual system.

It's like the Brown Noise for your brain!

https://www.youtube.com/watch?v=6ijI4HjTGkw

What are you supposed to look at? The center red dot?

This is some amazing work; and it also raises my belief that a Langford Basilisk is neurologically possible by about 25%

Thanks for introducing me to the concept! Just read the short story I assume you are referring to: https://www.infinityplus.co.uk/stories/blit.htm

Looks like it, according to Wikipedia: https://en.wiktionary.org/wiki/Langford%27s_basilisk

Just read the story, thought it was very reminiscent of one of the plot points in Neal Stephenson's Snow Crash (1992) - until I noticed the publication date of 1988, 4 years earlier!

You'll also find a similar concept throughout David Foster Wallace's Infinite Jest (1996).

Charles Stross who for some reason posted on usenet about it in the wikipedia article uses a form of this to great effect in several books in The Laundry Files

Accelerando : https://www.antipope.org/charlie/blog-static/fiction/acceler...

    Not everything is sweetness and light in the era of mature nanotechnology. Widespread intelligence amplification doesn't lead to widespread rational behavior. New religions and mystery cults explode across the planet; much of the Net is unusable, flattened by successive semiotic jihads. India and Pakistan have held their long-awaited nuclear war: external intervention by US and EU nanosats prevented most of the IRBMs from getting through, but the subsequent spate of network raids and Basilisk attacks cause havoc. Luckily, infowar turns out to be more survivable than nuclear war – especially once it is discovered that a simple anti-aliasing filter stops nine out of ten neural-wetware-crashing Langford fractals from causing anything worse than a mild headache.

(2005)

I hadn't heard of this one before, it's also similar to the crucifix glitch in Peter Watts' Blindsight

Having read both Blindsight and Echopraxia I have to say the most impressive neurological takeaway from the books was the ability of my own brain to suspend critical thinking for long enough to enjoy the books.

In retrospect the core concept can be paraphrased as: Self-awareness and consciousness in pigs is the only thing that prevents them from flapping their trotters fast enough to fly(to the moon).

I'm not getting your point? the book had some out there ideas but the core concept of consciousness not being necessary for intelligence seemed fairly reasonable.

Fantastic book. Really made me think in some new ways.

https://www.nature.com/articles/44964 is also a fun read on the BLIT.

I also recommend Different Kinds of Darkness.

https://www.lightspeedmagazine.com/fiction/different-kinds-o...

I'm interested to hear your reasons why you think it's closer to reality. I don't see why the discovery of the brain wastage system would help a brain crash from being possible. Edit: Just looked back at the post and that it involves an image causing the glymphatic system to react.

It's possible.

But only for the brains of people with severe or undertreated epilepsy of carefully selected varieties. You can trigger a potentially fatal seizure by showing them an appropriately stimulating image. Which likely was a known concept to the author of the story.

For the rest of us the negative feedback along the optical axis puts a stop to such shenanigans.

GenAI images sometimes do this to me. Not anything scary per say, but some of the faults make my brain feel weird as it tries and fails to interpret parts of the image that were "AI smeared".

https://en.wikipedia.org/wiki/McCollough_effect is evidence to the contrary. This seems to rewire something outside the optical pathway. The effect can last for months. Works on almost all brains, no epilepsy required...

That sounds more like a learned visual effect, something quite different from frying the brain of anyone with a basilisk.

Experiments with cats( https://pubmed.ncbi.nlm.nih.gov/1111849/ ), and the outcome of patients with strabismus/lazy eye(effective blindness on defective eye), suggests that seeing (or not seeing) is a learned trait. Which is a few steps removed from being a backdoor to epileptic seizures or remote controlling heart activity

Exert from that same wiki page about the anti-McCollough effect, I may have the two confused.

Given that AMEs do transfer interocularly,[8] it is reasonable to suppose that they must occur in higher, binocular regions of the brain. Despite producing a less saturated illusory color, the induction of an AME may override a previously induced ME, providing additional weight to the argument that AMEs occur in the higher visual areas than MEs.[8]

Sure, we know imagery can cause fatal seizures so... yes.

It is well established that visual patterns affect brain activity, this is used in clinical practice by neurophysiologists, put on an EEG cap and then do checkerboards, check if the activity is normal.

Now the question is if this provocation and resulting CSF flow is actually beneficial. Do you spike activity and get a rebound attempt at waste clearing due to waste accumulation of the neural spike, or is this like a massage for the brain that gives you a invigorating CSF dump?

I suspect it might not be a health improving activity. (I also suspect that you can get even more CSF flowing if you spin yourself at 6G in a full body centrifuge and that this too would not be conductive to health)

The paper says they used http://psychtoolbox.org/ to generate the images.

> Psychophysics Toolbox Version 3 (PTB-3) is a free set of Matlab and GNU Octave functions for vision and neuroscience research

Scientists almost never want to share their code and it makes me sad. Why wouldn't they want to make their paper more easily reproducible?

Because academic code is horrendous.

I once worked in an IT department of a genetics laboratory, which consistently publishes high impact papers in journals like Science and Nature.

While I was there I got to see some of the R/Python/Java code that had been created for all kinds of studies that had taken place there. It was some of the worst code I have ever seen.

But I do agree, the complete methodology including the code should be shared.

Staring at the v0.3 produces an effect similar to something I'm able to do trigger manually on command. I've always had the feeling that I'm somehow triggering a "flow" in my brain, but I have no way to confirm what's actually going on. It's actually stronger when I trigger it manually, and it feels like it flows down my spine and eventually some weak signal reaches my extremities. (Maybe that means it's not CSF after all?) Oddly, I do feel like I can think more clearly afterward, but the brain is very bad at judging itself, so it's more likely to be an illusion than anything real. Anyone else able to manually trigger a feeling like this in their brains?

How have you trained yourself to do that?

I'm not 100% sure, but it's something like this:

If you try raising one eyebrow or wiggling one ear (assuming you can't already do that), you might find that you're briefly activating lots of little muscles around the target as your body tries to figure out where that's mapped in your brain. Once you get the right muscle, you can relax the other false positives, and eventually just have the single muscle isolated. It's similar in my "brain flow" thing: usually a couple random muscles in my head want to join in, but I can intentionally relax them and keep the "flow" going. A common one is the tensor tympani -- the two "muscles" seem to be closely mapped together. If you can rumble your ears (manually activating the tensor tympani), try initiating a rumble, and then "move" the activation in between your ears, right to your mid-back brain. (Again: I know there's no actual muscle there, so /shrug). Another closely mapped muscle, at least for me, is a small one around/under/behind the ears that has a "face tightening" effect. It's like there are three muscles conceptually mapped to similar brain space: one tightens my ears/eyes/temples, one rumbles my tensor tympani, and one induces a feeling of "flow" down my spine and through my brain.

I'm interested in how you accomplish this. I can do something along the lines of that by getting myself heated. I actually get a hothead and a tingling comes up to my brain like it's passing in a channel. It could simply be a sensation rising within the brain though, without an actual transport of something.

I can focus better after but it doesn't clear my head, just use that frustration or anger to become determined.

I'm not quite sure exactly what I'm doing; it feels a bit like tensing a muscle, but that muscle feels like it's in the middle of my head, a bit toward the back. Obviously there are no actual muscles there, so I'm not sure what's actually happening.

I sorta get what you're saying, and tbh I've always found it hard to single out a single muscle from all the other tiny muscles around it. I can already raise one eyebrow alone, and I don't remember when I learned to do it so I don't remember the experience, but I do feel that 'single muscle vs many muscles' when I do that.

With the "muscle" in the mid-back of your brain, I understand that much more. If you respond well to meditation and get a sensation from asmr for instance, if we're speaking on the same area, that area gets sensations if the person is more prone to stress.

When I sort of make myself hotheaded, or have any drug, or even really relax, I feel sensations at that area. I wonder if you're the same.

That just sounds like ASMR, which some folks can induce without external stimuli.

I think you are thinking of Frission https://en.wikipedia.org/wiki/Frisson

No, the prior post's reference to having some degree of control over the sensation, plus a prolonged impact on mental state makes it distinctly ASMR, as opposed to frission which is usually a short-lasting involuntary response. [1]

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC6086079/

Yep, I can do that.

It's similar to the effect of being hit with big news (good or bad), and the "sinking" feeling that comes with it, becoming suddenly introspective and oddly calm under pressure.

At least to me, of course. I have no idea if others have that same reaction.

In me, there seemed to be an illusion going on. It felt like a tunnel and it felt as immersive as a "dream world" (albeit a bit of a boring one).

What I also noticed were the after image effects. A strong blue dot every time it flashed and circles divided into 8 sections like a star.

This was trippy.

Noticed that as well. Very trippy

The 40hz visual + auditory stimulation is showing to be surprisingly effective in mice and humans. [1] When I first heard this, I thought the open-loop nature, and the fixed frequency across subjects sounded improbable, but I'm happy to be proven wrong.

We work in the neurotech/sleeptech space doing slow-wave enhancement which, it is believed, increases glymphatic activity [2]. Recent studies have looked at the promise of alzheimer's prevention [3].

More links to research papers are on our website https://affectablesleep.com/science

[1] - https://www.nature.com/articles/s41586-024-07132-6 [2] - https://www.frontiersin.org/journals/neuroscience/articles/1... [3] - https://pmc.ncbi.nlm.nih.gov/articles/PMC10758173/

Very cool! Five minutes of this felt strangely soothing in my head, after a few nights of not enough sleep.

Being able to set a max duration would be neat, in case it's unsafe to lose track of time and let the pattern run for too long?

Classic outdated comment BTW ;)

  setInterval(flickerImage, 250); // 8hz

When I open the page, the image rotates for about ten seconds then vanishes. How do you watch it for five minutes? What did I do wrong?

As per the first line of the writeup on the page: It toggles between on and off every 16 seconds.

give it a bit, it then reappears (as described in the paper, btw)

Isn't that 4 Hz?

Exactly, the comment was carried over from V0.1 which set a 125 ms timer.

Thanks so much for creating and sharing this! Could you point me to any other independent research in this area? Also, as I read related journal articles, I'm trying to understand if the 40Hz sound is binaural (with a 40Hz difference between frequencies in each ear) or a straight 40Hz pulse (same in both ears). It's surprisingly hard for me to get a clear answer. Do you happen to have any experience with this or suggestions for related resources that might contain the answer? Thanks!

It seems to have no effect on me.

Am I an outlier?

Its very much experimental so we don't know if there are people for whom this has no impact, all the people in the studies respond so the question is whether your cerebral spinal fluid is being pumped around and flushing your brain and you don't feel an impact or whether you get no cerebral spine fluid movement at all. Someone would need to recreate this experiment with you in the MRI to find out which it is.

What is one supposed to experience or feel? Maybe my computer is too slow or my monitor is too small? I used to collect gifs that were similar to this just because they had a neat visual effect but neither those nor this image gives me any kind of experience. If I could find a private business that has an MRI I would pay cash to get a full body scan and then just a brain scan as I have always wanted one but hospitals around me want me to go through their process and give me strange looks when I just want to pay cash and be scanned. I think it would be interesting to see what effect assorted images have. There was another type of scanner, I forgot what it was called ... that would show a 3D image of the brain during activity and would show when parts of the brain that should be responding are not. In that study it was used primarily on kids/teens that were prone to crime. I can not remember what it was called. This was quite some time ago. The patient would have many wires attached to their head. It would effectively show animated holes so to speak when part of a persons brain was not functioning correctly due to physical trauma, drugs, etc...

The places that specialize in full body scans will do it for cash. I think technically you need a script for any MRI, so you may still need to speak with a doctor ar their facility first. My understanding is it's more streamlined there and will be way cheaper than any hospital. If you talk to your primary or can get a telemedicine appointment online then they might be willing to write you the script and you can go to a local MRI. I would avoid the hospital as they are 5x higher in cost than my local outpatient imaging facility.

I think technically you need a script for any MRI

I'm in the US. I am guessing a script is the same thing wherever you are as what is called a referral here. I will ask around. Thankyou for the idea. I will research what outpatient imaging facilities are around me. Would they use some kind of mirror system to watch this image? I can't imagine a PC could be near the MRI.

"script" is "prescription" (here in US and possibly elsewhere). Imaging techniques generally require them because medicine considers the potential harm of giving patients an inconclusive diagnosis or a conclusive diagnosis for which there's no treatment. Without a symptom to weigh against these risks, it makes some sense to consider them as not "over the counter".

But in practice I think you can show up at any imaging center and get some kind of "full body MRI" to screen for cancer or some other risk. They'll probably ask about family history and other predispositions but even if you didn't have those they'd still take your money.

I will give that a shot. A family member was a signalman for the railroad for over 40 years and got melanoma back when there was no treatment for it. Perhaps that may suffice.

After focussing on the dot for a few seconds the images appear to produce a tunnel or other change in effect from just images flipping, maybe a moving star. Then when the grey image appears you get an after effect of the overall image for about a second. Some feel a form of pressure or even light seizure sensation in the brain and have auditory experience like there was a sound that disappears each time the grey clearing screen appears.Then afterwards some people feel a bit cognitively fatigued, drunk even for a few minutes to hours.

It feels odd, its hard to describe it feels like something weird is happening in the brain.

Interesting. So I do get the over-shadow effect for about 1.5 seconds but I get that from any bright light that transitions to a grey background mostly from taking high dose benfotiamine, along with lutein and astaxanthin and chelated copper as my nervous system was being depleted of thiamine due to a dumb self induced issue that I have nearly resolved. Maybe I am not a good test subject for that reason. Or perhaps my monitor is too bright.

Edit: I reduced the brightness, contrast and changed the black mode of the monitor and went through several cycles. I still get the over-shadow effect for anywhere from 1.5 to 2 seconds but no other effects. Perhaps my supplements are interfering or confounding. I guess it may be useful to note what supplements the test subject is consuming along with dosage to determine if that is a confounding factor.

I don't feel anything either. Not sure why

Maybe try it again at the end of the workday?

I tried it again several hours later, being more tired, and on my 22" fullscreen instead of my phone.

Still nothing.

Try lying down and then watching the screen.

Why do you assume you're supposed to feel an immediate effect?

Increased CSF flow aids in clearing metabolic waste, distributing nutrients, and reduced oxidative stress. You'll feel none of this after a 3 minute session.

A lot of the reactions here reek of placebo.

I wonder how this will work with hypophantic and aphantic individuals (people with little to no "mind's eye" visual imagery), such as myself. Like would the effect still be registered the same as anyone else, or would it cause the imagery effect to lessen or be ineffective altogether?

I work in this field —- You’re mis-construing the research a bit. Your reference talks about CSF flow on a more macroscopic scale (clearance out the fourth ventricle), which is fundamentally different than the glymphatic system referenced in the original story.

This is fascinating.

Curious, could seizures caused by strobe light be related to the effects of draining of this fluid?

From the paper, it seems like that the blood flow changes and the seizures are both caused by the increased processing load in the visual cortex; with the seizures also resulting from some faulty wiring in localizing that increased load to only the visual cortex. So, more like A->B and A->C instead of A->B->C. But I'd bet this visual stimuli is even more effective at causing seizures in vulnerable people than an unfortunate pokemon episode.

Clearing the waste sounds like a good thing, I guess. Haven't got time to read the study, but can this have beneficial effects to do while awake?

It certainly feels quite strange after watching the prototype for 8 cycles.

I’d like to see if anyone with Fatal Familial Insomnia has been treated with this pattern. I expected that insomnia stops this glymphatic clearance, and that’s what eventually kills them.

Isn't it the prions gradually destroying their brain that's killing them?

I’m not aware of the root cause. I thought they just stopped being able to sleep, and the buildup of whatever junk in the brain eventually caused death.

No, you have the causality reversed. FFI is a prion disease. The insomnia is a consequence of the damage the prion proteins cause. The prions themselves will kill you, regardless of whether you were able to reproduce the biological effects of sleep in a patient. Insomnia is also also caused by other acute brain illnesses, like rabies.

Ah, smarter today than yesterday. Thx

Wow, that is wild. I never would have thought that simply watching images would trigger something in the lymphatic system. This could have huge implications for multiple diseases.

Fascinating. Can you go into more details explaining what your understanding of the paper is? I'm reading it now but I'm not familiar with the field.

For the cff page on Safari, create a bookmarklet to make it go pure full screen:

javascript:document.documentElement.webkitRequestFullScreen();

Holy cow.... that's really rough, you weren't kidding.

This is the closest I've ever felt to being a Borg.

I think I must have turned off repetitive play in browser. wonder if there is an m4v version

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