From reading dreams to helping locked-in patients — what the future of EEG could look like

The brainwave-reading technology of EEG helps monitor people with epilepsy and can detect when we're dozing off behind the wheel in a simulator. As scientists mark the 100th anniversary of the test, here's why many in the field are excited about its future uses in medicine.

Today's electroencephalogram, or EEG, device consists of electrodes applied to the patient or subject's scalp in order to collect and provide images of brainwaves noninvasively. It's been used to tell if someone with a serious brain injury who seems unresponsive can communicate yes/no answers, as well as to control devices like drones and wheelchairs.

In a commentary in the latest issue of the journal Nature Human Behaviour, Faisal Mushtaq, a professor of cognitive science and the director of the Centre for Immersive Technologies at the University of Leeds in England, and his team discuss responses to a survey of more than 500 experts who work with EEG — from neuroscientists to brain surgeons.

Their consensus is that being able to reliably diagnose seizures or brain tumours in real time is just 10 to 14 years away. But the chances of reading the content of our dreams and long-term memories is judged to be more than 50 years away by some experts — and considered closer to science fiction by others.

Neuropsychologist Sarah Lippé, a psychology professor at Université de Montréal, uses EEG in her research on childhood brain development in autism spectrum disorder and attention-deficit hyperactivity disorder (ADHD), as well as on how epilepsy can contribute to cognitive impairments in children.

Lippé, one of the co-authors of the commentary, pointed to how methylphenidate, sold under the brand name Ritalin, is commonly used to treat ADHD in children. "We can see that it rescues some of the basic signals of sensory processing in these children."

Since EEG is so sensitive at picking up both normal brain maturation and delays, if a physician has a question about whether someone's symptoms are from ADHD, Lippé said that EEG can help confirm it.

Adrian Owen, a professor of cognitive neuroscience at Western University's Schulich School of Medicine and Dentistry in London, Ont., said EEG is key for patients he works with in the intensive care unit who've recently had a serious brain injury.

"For those patients, it's really hard to get them into an MRI scanner," said Owen, who was not involved in the commentary. "Having another way of detecting awareness with them in the ICU, so we take the whole thing to their bedside and test ... is hugely important."

Owen said his work with people thought to be completely "locked inside" their head while able to think, form opinions and understand what's happening around them is now broadly recognized by the medical community, including recently in the esteemed New England Journal of Medicine.

"Not only does it exist, it's actually rather common, and I think that's something that's really changed the status quo," Owen said. Doctors and family members no longer assume that a patient is unconscious just because they're unresponsive, a sea change in approach from decades ago, he added.

Owen said it's interesting that the paper examines how reading dreams based just on the "squiggly lines" of an EEG will likely remain in the realm of science fiction, and compares that notion with what he views as "extremely plausible" applications — such as working out whether someone is awake while driving or flying, or fully sedated in the operating room.

But to read someone's dreams isn't just a matter of EEG technology evolving to handle it. Owen said to decode dreams, a whole new technology would need to be invented, which is why the idea remains fanciful.

The paper published in Nature Human Behaviour also raises ethical minefields.