Flickering light mobilizes brain chemistry that may fight Alzheimer's

Though conducted on healthy mice, this new study is directly connected to human trials, in which Alzheimer’s patients are exposed to 40 Hz light and sound. Insights gained in mice at the Georgia Institute of Technology are informing the human trials in collaboration with Emory University.

The 40 Hz frequency stems from the observation that brains of Alzheimer’s patients suffer early on from a lack of what is called gamma, moments of gentle, constant brain waves acting like a dance beat for neuron activity. Its most common frequency is right around 40 Hz, and exposing mice to light flickering at that frequency restored gamma and also appears to have prevented heavy Alzheimer’s brain damage.

In the current study, the surging cytokines hinted at a connection with microglial activity, and in particular, the cytokine Macrophage Colony-Stimulating Factor (M-CSF). The researchers will look for a causal connection to microglia activation in an upcoming study, but the overall surge of cytokines was a good sign in general, they said. “The vast majority of cytokines went up, some anti-inflammatory and some inflammatory, and it was a transient response,” Wood said. “Often, a transient inflammatory response can promote pathogen clearance; it can promote repair.”

The 40 Hz stimulation did not need long to trigger the cytokine surge. “We found an increase in cytokines after an hour of stimulation,” Garza said. “We saw phosphoprotein signals after about 15 minutes of flickering.”

As controls, the researchers applied three additional light stimuli, and to their astonishment, all three had some effect on cytokines. But stimulating with 20 Hz stole the show.

“At 20 Hz, cytokine levels were way down. That could be useful, too. There may be circumstances where you want to suppress cytokines,” Singer said. "We’re thinking different kinds of stimulation could potentially become a platform of tools in a variety of contexts like Parkinson’s or schizophrenia. Many neurological disorders are associated with immune response."

The research team warns against people improvising light therapies on their own, since more data is needed to thoroughly establish effects on humans, and getting frequencies wrong could possibly even do damage.


I have listened to 40hz sounds via youtube. Have read that 40hz lights are not valid via a computer or tv. Supposedly, these devices do not hsve the capability. Strobe lights however can be set at real 40hz.

Here’s the previous thread on this

I didn’t really use it anymore as I felt it was unwise to continue given the whacky effect the light goggles were having on my vision @40hz.

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It seems like the scientists here speculatively suggested that 20hz might be better for schizophrenia, although they warned about self-experimentation since it might be harmful. It does seem like you would need to know since 20hz and 40 hz had completely different effects on cytokines. Wouldn’t want to guess wrong and push things in the wrong direction.

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