Imagine if people with epilepsy could prevent a seizure before it even started by halting the abnormal brain signals that trigger it. We haven't reached that stage yet, but researchers at McGill University have taken a major step in that direction.

In a proof-of-concept study just published, the researchers have shown that people can control the activity of specific regions of their brain when helped by a new imaging technique called magnetoencephalography (MEG).

Though still in its infancy, neurofeedback has great potential for use in virtually every disorder of the brain, from stroke to depression.

The idea of biofeedback — people regulating their own brain activity through viewing information recorded from their brain — isn't new, but its use as a treatment has been limited by the technical difficulty of displaying brain activity accurately and quickly. Much of the work in the field has been done using recordings made by scalp electrodes (EEGs), which are poorly suited to the task and give very limited spatial resolution.

MEG is a much better tool. This non-invasive brain scan offers neurofeedback — it measures tiny magnetic fields generated by brain cells millisecond by millisecond across the entire brain, and it doesn't require radioactive isotopes. When it is combined with magnetic resonance imaging (MRI), it's possible to see a real-time color display of the ongoing activity throughout the entire brain.

Subjects in this early study of MEG's usefulness for neurofeedback were shown a dark red colored disc and had to figure out a way to change the disc's color to bright yellow-white, without moving any parts of their body.

Unknown to the subjects, the disc color was based on the activity of specific regions of their brain's motor cortex. The only way to change the color was for the subjects to alter the activity in these regions of their brain.

Not only did the subjects figure out how to do this during nine training sessions; as the sessions progressed, participants demonstrated an ever-growing ability to make larger and larger changes.

“The remarkable thing is that with each training session, the participants were able to reach the target aim faster, even though we were raising the bar for the target objective in each session, the way you raise the bar each time in a high jump competition.

“These results showed that participants were successfully using neurofeedback to alter their pattern of brain activity according to a predefined objective in specific regions of their brain's motor cortex, without moving any body part,” said Sylvain Baillet, an associate professor of neurology and neurosurgery at the Montreal Neurological Institute of McGill University in a statement.

Though still in its infancy, neurofeedback has great potential for use in virtually every disorder of the brain, from stroke to depression. So far, work with epilepsy patients has shown the most promise.

The new technique may even help you train yourself to sing on key. Research clinicians recently began to apply MEG-based neurofeedback to people with amusia, a condition that makes them unable to distinguish musical pitch.

It's thought that amusia is caused by poor connectivity between two brain regions — the auditory cortex and the prefrontal region. Scientists hope that through training sessions, amusia patients will be able to be increase the connectivity between these regions, and thereby improve their pitch discrimination.

An article on the study appears in NeuroImage.