Brain fog from chemo & Alzheimer's plaque reduced by gazing at 40 Hz flickering strobe light

[Hip]

SUMMARY: This post details a 40 Hz strobe light treatment that can be done at home (free apps can turn your smartphone flashlight into a strobe). The treatment has beneficial effects on the brain: it is shown to reduce brain fog from chemotherapy, and shown to reduce the progression of Alzheimer's disease, by clearing plaque from the brain.

The flickering light treatment works by evoking gamma waves in the brain, which in turn stimulate the brain's microglia into their brain repair and brain garbage collecting mode.

This article details how in a mouse experiment, brain fog resulting from chemotherapy was mitigated by exposing mice to flickering strobe lights at a frequency of 40 Hz (which stimulates the brain to produce 40 Hz gamma waves).

Chemotherapy normally results in damaging effects on the brain: a smaller brain volume, DNA damage, neuroinflammation, and damage to the myelin sheaf around neurons. These effects were seen in mice given chemotherapy drugs.

But in the mice given chemotherapy along with 40 Hz strobe exposure, these ill effects were reduced.

The strobe treatment was found most effective when given at the same time as chemotherapy; it was less effective when given after the chemotherapy was over. The study is here.



Similarly, this article details and experiment on mice engineered to overproduce tau proteins (the brain-damaging protein found in Alzheimer's disease). In these animals, it was found that mice exposed to a 40 Hz strobe light for one hour daily had no neuronal degeneration whatsoever, whereas the mice not given the strobe treatment suffered a 20% loss of neurons as a result of the toxic tau protein.

So the 40 Hz strobe light seems to entirely prevent toxic brain damage from tau protein. The study is here.

This article says:

Li-Huei Tsai and colleagues at MIT's Picower Institute for Learning and Memory first discovered in 2016 that amyloid and tau proteins seemed to be eliminated from mouse brains following exposure to a flickering light.

And small-scale study on patients with Alzheimer's disease found that 40 Hz strobe exposure for one hour daily prevented further deterioration of their brain over the 4 month period of the study; whereas the control group of Alzheimer's patients not give the strobe treatment showed the usual Alzheimer's disease progression.



This article gives more details about the mechanism by which the 40 Hz strobe works:

After an hour of stimulation, the researchers found a roughly 50% reduction in the levels of beta amyloid proteins in the hippocampus, the brain’s memory centre. Closer inspection showed that the amyloid had been taken up by microglia, the brain’s immune cells.

In a healthy brain, microglia act as chemical rubbish collectors, surveying the local environment, clearing up unwanted compounds, but in Alzheimer’s these cells can lose this function and switch into an inflammatory state in which they secrete toxic compounds instead. Strengthening gamma oscillations appeared to switch the microglia back into a productive state.

So it seems that the strobe light, via the gamma waves it evokes in the brain, are prompting microglia to switch to garbage clean up mode, clearing the brain of rubbish.

I believe this clean up operation refers the M2 repair mode of the microglia (which contrasts to its M1 pathogen kill mode). Several supplements (see the end of this post) also help switch to the M2 repair mode.


This paper explored the effects of a 40 Hz light strobe on the human brain, and found a 40 Hz flicker consistently produced brain wave entrainment in test subjects. Brain wave entrainment means when the externally imposed frequency causes brain waves to oscillate at that same frequency.


This article details a replication study which failed to observe the plaque reduction seen in the original study by Li-Huei Tsai. The article questions whether methodological differences might explain the discrepancy.



In this Reddit thread, someone created a webpage which flashes at 40 Hz (if you are epileptic, you might want to be careful looking at this). So this is one way to try this strobe treatment at no cost, to see if it might help with ME/CFS brain fog or other ME/CFS symptoms.

EDIT: this webpage is faulty, it actually flashes at 20 Hz, not 40 Hz (see this post below).



I also found this stroboscopic webpage, which allows you to set the strobe frequency anywhere from very slow, right up to 60 Hz.

Someone has also written an Android and iOS app to not only produce the 40 Hz flicker on screen, but to couple this with a 40 Hz sound, which strengthens the effect. Unfortunately you have to subscribe, so it is not free.


Note that on computer, phone or tablet screen with a 60 Hz refresh rate, a 40 Hz flicker will not display properly. You would need a screen with at least an 80 Hz refresh rate to display a 40 Hz flicker.

EDIT: a better option for displaying a 40 Hz flicker is using a strobing app which flashes your phone's flashlight 40 times per second, such as the Strobily strobe app detailed in this post). Strobily seems to work well on my newer Android phone, but does not seem to work that well on some older phones I tried it on.

 

[Wishful]

Do the papers mention the limit range of the effect? Is it only 39.5 - 40.5 Hz, or does 50 Hz have a similar effect? Note that a fair portion of the world uses 50 Hz AC power, resulting in plenty of exposure to 50 Hz light flicker, so that's a large-scale test of that hypothesis. 60 Hz must not work, because I can't recall any PWME reporting reduction in brainfog after screen time. I'm not sure whether typical monitors on 50 Hz AC have a 50 Hz (or multiple of) refresh rate.

 

[Hip]

Do the papers mention the limit range of the effect? Is it only 39.5 - 40.5 Hz, or does 50 Hz have a similar effect?

Gamma brain waves have frequencies from 30 Hz to 80 Hz.

But whether a strobe light set in that frequency range will entrain the brain to oscillate at the externally applied strobing frequency is another question.

Also, whether other gamma frequencies have the same strength of effect on the brain's microglia as 40 Hz is another question. 40 Hz is generally considered the sweet spot in these gamma wave entrainment studies.

The entrainment study I mentioned earlier says:

In mouse models of Alzheimer’s disease (AD) and stroke, low gamma frequency light flickers at frequencies from 30 to 50 Hz entrain brain oscillations in the visual cortex and hippocampus.

So we can say that 30 to 50 Hz will entrain brain to oscillate at the same frequency; but whether you get the same strength of effect on microglia at say 50 Hz compared to 40 Hz, I don't know.

Note that a fair portion of the world uses 50 Hz AC power, resulting in plenty of exposure to 50 Hz light flicker, so that's a large-scale test of that hypothesis.

Interesting point. Though it may be the mild flicker produced by say fluorescent tubes or LED lights flickering at 50 Hz is not strong enough. If you stare at the flicker produced by the this webpage which flashes at 40 Hz, it's very noticeable, whereas fluorescent tube flicker is normally not noticed at all.



We should bear in mind that chemotherapy brain fog may be different to ME/CFS brain fog, so a 40 Hz strobe might not work for ME/CFS brain fog.

Nevertheless, if 40 Hz strobing can throw the brain's microglia into the M2 repair mode, rather than the M1 "kill" mode, this could have benefits for ME/CFS.

Studies have found chronic enterovirus infections in ME/CFS patient brains; so that might place microglia in their M1 kill mode most of the time, constantly trying to tackle the virus, and not doing enough M2 repair work in the brain.

So a shift to the M2 repair mode via 40 Hz strobe light exposure could be beneficial by triggering M2 mode garbage collecting and housekeeping tasks in the brain.

 

[Hip]

If you wanted to check the degree of brain wave entrainment that occurs with different gamma wave frequencies, one could buy the $130 NeuroSky MindWave EEG device, which monitors the strength of brain waves (in the gamma, beta, alpha, theta and delta bands), and displays your brain waves in real time on an app, like this:

NeuroSky MindWave EEG Device

 

[hapl808]

If you wanted to check to see how much brain wave entrainment occurs with different gamma wave frequencies, one could buy the $130 NeuroSky MindWave EEG device

I haven't researched this kind of stuff at all, although I love the idea. I know we are basically unable to measure brain neurotransmitter level in most situations, despite the promises from various urine tests, etc.

What's your thoughts on EEG value? Since cognitive triggered crashes are one of my worst symptoms - I can actually feel that whenever I'm engrossed in something, I am likely to trigger a crash. It's torture, because basically anything I enjoy, I know I will pay a price.

If there some way to get additional info from EEG, that seems worth it - but not sure if flow state, concentration, etc - reliably show up on such consumer devices?

 

[Hip]

What's your thoughts on EEG value?

Decades ago, when I was healthy, I was into Zen mindfulness meditation, which as you may know, amplifies the deep relaxation and conscious-expanding alpha and theta brain waves. In those days, I would have loved to experiment with a technology like the NeuroSky MindWave EEG, to monitor the depth of medication.

Since getting ME/CFS though, I find I have no ability to get into these meditative states, so while I am still curious, I've never ventured to buying the MindWave thus far, as I am not sure if it has any application in ME/CFS.

The MindWave is the cheapest of the consumer EEG devices. It is convenient, as it does not use a wet electrode, it is a dry electrode system, so is easier to use. Though wet electrode systems are considered better, in terms of sensitivity to detecting brain waves.

There are other brands of consumer EEG: the Muse, and the Emotiv. The Emotiv is a wet system, and requires saline or electrically conductive gel placed on the skin under the electrodes.

The main technological challenge with these EEG machines is filtering out the electrical signals created by the nerves which move the muscles in the face and head. These muscle nerves create a stronger signal, which can swamp out the brain wave signal if they are not filtered.

From what I have read, I believe these consumer EEG machines, although less accurate than research grade EEG machines, are still accurate enough to be used in studies in some cases.

 

[sb4]

Would be interesting if somebody tried this technique with a EEG. Good find.

 

[Florida Guy]

Wow hip you constantly come up with new and interesting stuff. I had to take chemo a few years ago and I will definitely try the strobe page and if it works, I'll get one of those strobes. If it helps a lot we should put up a statue to you or something. Of course I know not to get hopes up too high but several things I've learned here have helped already

As I recall from other studies, 40hz is kind of a stimulating frequency, it can rev you up while lower frequencies had a calming effect much like alpha and beta waves are lower frequency. I should get one of those eeg things, I didn't know they were so cheap. Has anyone used them, are they easy to use, painful or what?

I've had an eeg and the contacts were a little uncomfortable plus they said I cheated and did not stop all muscle activity. I tried to stop it but I don't know what was wrong. I would like to read reports on using the device

 

[Viala]

If you wanted to check the degree of brain wave entrainment that occurs with different gamma wave frequencies, one could buy the $130 NeuroSky MindWave EEG device, which monitors the strength of brain waves (in the gamma, beta, alpha, theta and delta bands), and displays your brain waves in real time on an app, like this:

Wow, looks like an awesome device to monitor meditation. Good biofeedback. They could make a game out of this to train the mind, no more wondering which brain wave we're in and how deep we go.

 

[Cipher]

Very interesting! It seems like the codepen.io page is misconstructed, as it only oscillates at 20 Hz (I think the developer equated changes to Hz, even though Hz is a whole cycle). This is visible by checking the source code button at the top right. I tried doubling the number of oscillations in the source code, but it didn't look that different, so I wonder if the code's approach is flawed somehow.

I think the other site, moodlight.org, suffers from the same problem, as setting it to changing the colour 40 times a second means that the Hz is 20 (unless I'm misunderstanding!). Setting it to 80 doesn't seem possible.

I found this app which seems to support both screen oscillation as well as sound (which seem to be in sync). My phone doesn't support higher than 30 Hz screen oscillation though (as the display is 60 Hz).

The human study used light in combination with sound; I wonder how effective sound is alone?

 

[Hip]

I found this app which seems to support both screen oscillation as well as sound (which seem to be in sync). My phone doesn't support higher than 30 Hz screen oscillation though (as the display is 60 Hz).

That app is a great find! Completely free too.

With this app on my phone, I also cannot go higher than 30 Hz screen oscillation, due to my phone display refresh rate being 60 Hz; but the app also gives the option of flashing the phone torch (flashlight), and this seems to work very well, and can be set to oscillate 40 Hz.

If I flash the torch at 40 Hz, and hold the flashing torch at the bridge of my nose with my eyes closed, it creates a strong strong strobe effect in both eyes.

So this might be the best option for anyone who has a torch on their phone.

Very interesting! It seems like the codepen.io page is misconstructed, as it only oscillates at 20 Hz (I think the developer misunderstood that Hz is a whole cycle).

Well spotted. I think you are quite right: I check the CSS code, and it does in fact oscillate an 20 Hz. It would be easy enough to fix this code to make it oscillate and 40 Hz.

But thinking about it, a 60 Hz display (the most common on computers and phones) will never be able to flash faster than 30 Hz, so it's not really worth fixing it (unless of course we found some info indicating that the effect of 30 Hz gamma waves on the brain is just as good as 40 Hz waves).

 

[Hip]

As I recall from other studies, 40hz is kind of a stimulating frequency, it can rev you up while lower frequencies had a calming effect much like alpha and beta waves are lower frequency.

Yes, decades ago, when I was reading about the various brain waves involved in Zen and mindfulness meditation, gamma was not talked about, and the interest was on how meditation would effect levels of beta, alpha and theta waves.

I still have a book I bought in the 1990s called the The Awakened Mind by Cecil Maxwell Cade, who back in the 1970s was a pioneer exploring beta, alpha, theta and delta rhythms in the context of meditation. This book mentions nothing about the gamma rhythm, because I guess gamma was not known about in those days, or was not measurable (the gamma band overlaps with the electrical signals from facial muscle movements, and only advanced filters can separate out the gamma signal).

The book says:

Beta rhythm 13-30 Hz — The normal waking rhythm of the brain associated with active thinking or active attention, focusing on the outside world or solving concrete problems.

Alpha rhythm 8-13 Hz — The most prominent rhythm in the brain, but also the one with the least apparent meaning, unless other associated rhythms are known. It denotes an empty mind rather than a relaxed one; a mindless state rather than a passive one. One person in ten produces no alpha at all. Alpha per se is not associated with with inwardly directed attention, relaxed awareness or feeling of wellbeing. These alpha states seem to require the simultaneous presence of beta and theta for there to be any addition to the "no mind" state.

Theta rhythm 4-7 Hz — Alone, this frequency appears in dreaming or in the half-waking hypnagogic state with dreamlike imagery. Theta appears as consciousness slips towards drowsiness. Theta has been associated with access to unconscious material, creative inspiration and deep meditation, but these states will be found to be accompanied by other frequencies in the alpha and beta bands, or with alpha alone during meditation.

Delta rhythm 0.5-4 Hz — Primarily associated with deep sleep.

The gamma rhythm 30–80 Hz is found to be stronger in experienced meditators. Gamma is associated with conscious attention, and with the brain making new connections (neuroplasticity),

 

[junkcrap50]

This is very similar to research that recently research showing how intense visual stimuli can induce glymphatic flow: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002035. They found 8hz and 12hz, as well as 40hz to be effective.

Neural activity induced by sensory stimulation can drive large-scale cerebrospinal fluid flow during wakefulness in humans​

• Stephanie D. Williams, Beverly Setzer, Nina E. Fultz, Zenia Valdiviezo, Nicole Tacugue, Zachary Diamandis, Laura D. Lewis

• Published: March 30, 2023
• https://doi.org/10.1371/journal.pbio.3002035

Abstract​

Cerebrospinal fluid (CSF) flow maintains healthy brain homeostasis, facilitating solute transport and the exchange of brain waste products. CSF flow is thus important for brain health, but the mechanisms that control its large-scale movement through the ventricles are not well understood. While it is well established that CSF flow is modulated by respiratory and cardiovascular dynamics, recent work has also demonstrated that neural activity is coupled to large waves of CSF flow in the ventricles during sleep. To test whether the temporal coupling between neural activity and CSF flow is in part due to a causal relationship, we investigated whether CSF flow could be induced by driving neural activity with intense visual stimulation. We manipulated neural activity with a flickering checkerboard visual stimulus and found that we could drive macroscopic CSF flow in the human brain. The timing and amplitude of CSF flow was matched to the visually evoked hemodynamic responses, suggesting neural activity can modulate CSF flow via neurovascular coupling. These results demonstrate that neural activity can contribute to driving CSF flow in the human brain and that the temporal dynamics of neurovascular coupling can explain this effect.

Here is the paper author showing the stimulation (warning, flashing screen): https://x.com/stephaniedwill/status/1644879727168040961

A LC patient recreated the it here too: https://www.paulkeeble.co.uk/posts/cff/ (source)

 

[Cipher]

With this app on my phone, I also cannot go higher than 30 Hz screen oscillation, due to my phone display refresh rate being 60 Hz; but the app also gives the option of flashing the phone torch (flashlight), and this seems to work very well, and can be set to oscillate 40 Hz.

If I flash the torch at 40 Hz, and hold the flashing torch at the bridge of my nose with my eyes closed, it creates a strong strong strobe effect in both eyes.

So this might be the best option for anyone who has a torch on their phone.

I wonder if the flashlight is reliable in showing an exact frequency; when I try setting it to 60Hz on my phone it's still visibly flickering, even though it shouldn't be discernible?

After checking some more it seems like my phone can't keep up. I tried this app which somehow verifies the Hz, and it says it's around 31-39 Hz even though I set it to 40 Hz.

 

[sb4]

So just trying to wrap my head around this. If you wanted say a 60hz wave, you would have to have a monitor capable of refreshing at 120hz because one frame is black and the other is white and only the white frames "count"?

 

[Hip]

I wonder if the flashlight is reliable in showing an exact frequency; when I try setting it to 60Hz on my phone it's still visibly flickering, even though it shouldn't be discernible?

According to this study, humans can detect light flicker up to 90 Hz (the point at which you can no longer see the flicker is called the critical flicker fusion frequency).

I think you don't notice 50/60 Hz main hum flicker in incandescent bulbs and fluorescent tubes because during the power off part of the cycle, the light level only drops a bit, and does not drop down to zero, as this graph shows:

Light Output Graph for Incandescent Bulbs, Fluorescent Tubes and LEDs

Source: here

Even mains LED lights these days are designed to run with minimal flicker:

Based on new advancements and a bigger push for safer LEDs, now LEDs can perform with impressively low amounts of flicker. Some well-crafted LED bulbs run anywhere from 0% to 5% flicker!

 

[Hip]

So just trying to wrap my head around this. If you wanted say a 60hz wave, you would have to have a monitor capable of refreshing at 120hz because one frame is black and the other is white and only the white frames "count"?

Yes, if you had a monitor running at 120 Hz, you could generate a 60 Hz flicker by having one frame black, then the next frame white, and the next frame black, and so on, repeating this cycle.

 

[Hip]

This Android app called Strobily might be a good choice for accurate phone flashlight strobing. It claims to be "the most accurate strobe light app on Android" with "millisecond precision LED flashing".

It contains a feature that allows you to calibrate your record turntable speed using the LED strobe, so presumably it must be pretty accurate to offer that facility.

 

[Hip]

Just came across a company called Gamma Light Therapy who sell a special LED bulb which flickers at 40 Hz, for the purpose of treating Alzheimer's and other conditions.

They have a blog article detailing which conditions this therapy may work for:

GAMMA LIGHT THERAPY RESEARCH

1. Alzheimer's Disease Studies are on going to determine if gamma frequency stimulation can help reduce amyloid-beta plaques and enhance the function of microglia, the brain's immune cells responsible for clearing waste and toxins (Iaccarino et al., 2016). This may help slow the progression of Alzheimer's disease and improve cognitive function.

2. Parkinson's Disease Gamma light therapy may improve motor symptoms in Parkinson's disease patients by promoting the release of dopamine, a neurotransmitter responsible for controlling movement and reward (Petersen et al., 2018).

3. Depression and Anxiety Gamma brainwave stimulation has been found to have a positive impact on mood and anxiety, possibly by enhancing the release of serotonin, a neurotransmitter that plays a key role in regulating mood (Ménard et al., 2019).

4. Epilepsy Some studies have reported that gamma light therapy can reduce seizure frequency and severity in individuals with epilepsy, possibly by stabilizing neural networks and inhibiting hyperexcitability (Sorokin et al., 2020).

5. Cognitive Enhancement Gamma brainwave stimulation has been linked to improved attention, memory, and overall cognitive function in healthy individuals (Palva & Palva, 2018).

 

[Hip]

This study examines the effects of 40 Hz strobes using different colours, with the purpose of trying to maximise the effect on the visually evoked potential, but minimising the disturbing sensation of flickering light.

The study found that colours at the ends of the spectrum (red and blue) produce stronger visually evoked potential, and suggest that flicker which oscillates from red to amber might minimise disturbance while maximising the effect.