Valkee, the bright-light headset manufacturer that claims to treat S.A.D. and other mood disorders, has seen its fair share of criticism after rushing to promote the scientific legitimacy of the device based on what came across as weak evidence to many people.

But more research on Valkee has been published, showing that light has a biological response in the brain. Unlike the past studies on the effects of the Valkee headset, this study was run in a placebo controlled environment and measured the physical response. The 51 participants were blindfolded, and bright light was delivered to the ear using optical fiber, which does not heat up. The paper be found online in the World Journal of Neuroscience.

According to the paper, the real-time functions of the brain’s resting state neural networks were measured in the study using fMRI, making it possible to locate the regions of the brain where the amount of blood and its oxygen saturation changed in response to bright light.

The study was completed at the Oulu University Hospital, and was steered by Vesa Kiviniemi, PhD, a respected scientist in the area and a reviewer to several journals. Dr. Kiviniemi and his group earlier published on fMRI methodology linked to identifying changes in the SAD brain.

“The research results confirm that it is possible to influence brain functions with bright light delivered directly to the brain through the ear,” says researcher Tuomo Starck from the Oulu University Hospital. “The group that received bright light demonstrated in the analysis significant increase in neural network activity especially in brain areas connected with visual perception.”

Timo Ahopelto, an investor in Valkee through the accelerator, Lifeline Ventures, points out, “In science and therapies, showing response is sometimes even more important than showing clinical efficacy, as clinical efficacy can be placebo but biological response seldom is. This is the hard science stuff.”

The last paper published on Valkee did little to resolve criticism after using a small sample size and relying on participants’ responses to a psychological survey. The study was also published in a journal with a colorful history, and only recently began peer-reviewing studies. But it’s good to see this latest study is much more robust.

Lifeline Ventures is a Vigo Accelerator.