Georgia Tech researchers study pulsing light as non-invasive Alzheimer's disease treatment

Can high-frequency flickering light help people living with Alzheimer's disease? 

That is a question Anabelle Singer, the McCamish Foundation Early Career Professor of biomedical engineering at Georgia Tech has been trying to answer. 

Singer and her team are studying whether a 40 Hertz light and sound delivery system can stimulate the brain, and, they hope, boost cognitive function. 

"It's really fast. So 40Hz means that it's turning on and off 40 times per second," Singer says. 

That means the light is flickering 4 times faster than a strobe light, she says. 

In earlier animal studies involving mice, Singer says, the pulsing light appeared to stimulate immune cells in the mice's brains, helping them clear damaging beta amyloid plaques that are a hallmark of Alzheimer's disease. 

"We found that we can significantly improve memory with using this 40Hz flickering stimulation for a week, for an hour a day," Singer says, talking about the animal research. 

With their current system, volunteers sit in a dark room in front of a screen, pushing a button each time a dot in the center changes color.   

Around the screen is a band of pulsing light. 

Singer says the flickering light enters their eyes and stimulates the brain's visual circuitry at 40Hz. 

"What was surprising to us was that that's not just happening in sensory brain circuits," she says.  "It goes beyond that. There's modulation in what we might call cognitive circuits, or circuits that are important for memory, for attention, for, executive functions, like multitasking and things like that." 

Researchers have tested a slightly different system with volunteers at home, she says. 

"And we found, surprisingly, our patients were really great users of the device," Singer says. "They reliably did it every day, day after day." 

This system, Singer says, is not the only way to stimulate brain activity. 

"But it's incredibly non-invasive," she says.  "It's something that we can use at home repeatedly.  
I think it's a game changer in its accessibility." 

They are still testing this technology, and clinical trials will likely take a few more years, she cautions. 

Singer says to be wary of commercial products that claim to deliver high frequency light stimulation, because, she says, there is no way to confirm these systems are using the right frequency of light. 

"And in fact, some of them, I'm pretty sure are not," Singer says.  "So, that's a consumer beware. If you look this up, and you find some 'Oh, I can buy my own 40Hz stimulation device," (remember) that's not been medically tested or FDA-approved. Please proceed with caution."