The science of brain-computer interfaces is developing quickly, as researchers create devices that can be worn on the head to help people who are disabled control technology, or even allow gamers to play with their minds alone.

But researchers are warning of extraordinary medical claims from other wearable devices that read signals from or stimulate the brain.

A new report from researchers at the University of British Columbia looked at claims from manufacturers of wearable "neurodevices." The claims included improving sleep, reducing stress, improving performance at music or sports, and even helping with certain neurodegenerative diseases such as ALS, the disease that killed Stephen Hawking.

The researchers are concerned that these claims are not always backed up by scientific proof and the devices should be used with caution.

Experiments in laboratory settings have shown that electrical stimulation to the brain can have a range of effects on the brain. We recently looked at the way it can have an impact on memory in older adults on Quirks & Quarks. The scientists working on it are certainly interested in pursuing this as a possible therapy for memory loss, but these are preliminary studies that are mostly still aimed at understanding fundamental questions about how memory works.

A volunteer receiving transcranial magnetic stimulation in a research study looking at how it might improve memory. (Joel Voss)

There are a huge number of unanswered questions about how to do this most effectively, and even whether it can be done safely over longer periods of time.

The researchers in this new report found that commercial devices are getting ahead of the science with vague claims by the manufacturers such as "a proven method to train the brain…" or a "drug-free way to learn to focus."

In some cases, the claims were more extraordinary, such as dealing with anxiety, stress-related issues, ADD, ADHD and PTSD, or the most extreme, a device that can "show how a person with … amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases could regain more independence."

Extraordinary claims made by the manufacturers of technologies like these — and other health claims made by manufacturers of food supplements, or companies selling genetic testing, often get ahead of the established science.

For this report, for example, the researchers looked for peer-reviewed research that would be consistent with the claims of the device manufacturers.

They found that, out of 41 "neurowearables," only eight had relevant peer-reviewed papers that supported the overall claims for the devices. Many of the others had references to support "associated claims" but no strong evidence that their devices actually did what they claimed.

Instead, there were "user testimonials, grey literature, company/in-house research, or peer-reviewed literature that was irrelevant to the device or claim at hand."

The researchers also noted that while the manufacturers made claims of benefits for the devices, they largely avoided mention of any potential risks.

In a statement, report author Judy Illes expressed particular concern about the marketing of these devices to children, who might be particularly vulnerable. "Their bodies and brains are still developing."

This report is a caution for users of wearable devices that claim to improve brain function to be wary of unsubstantiated claims and not turn to this technology in favour of conventional medical interventions.

Our brains are the most sophisticated calculating devices in the known universe. Much of the way they function is still unknown. If we are going to interfere with the way they work, it is better to know what we are doing first.