Instant brainwatching

It is all about having things under control – cars, unmanned aircraft and minds. The MOVIII Strategic Research Centre at Linköping University is now coming to its end, but the exciting research carried out there will continue.

In her book Hon älskade (“She Loved”), Swedish author Helena Henschen writes about a German scientist who smuggled out a third of Lenin’s brain after his death. He wanted to know if there was anything special about a brain that could think great things.
These days he could have just put Lenin into a magnetic scanner, preferably whilst still alive so that there would be some thoughts to study.

In other words, it is sufficient to think of something new in order for that thought to be registered by the scanner and displayed on a computer screen. The active areas of the brain are coloured in blue, green, yellow and red.
But that is already old news. Development of that technology took a great leap forward when it was successfully used to show a brain’s activity in real time; whilst its owner is still lying in the scanner, he can receive direct feedback. This opens up fascinating possibilities – for the first time in history, it is possible to see your own brain.
“A person lying in the scanner can observe their own brain activity and control things by thought alone”, says Hans Knutsson, professor of medical informatics at Linköping University.

The technology with the abbreviation fMRI (functional Magnetic Resonance Imaging) took its first steps in the early 1990s. A problem that needed to be overcome was how to develop useable images from the extremely weak signals picked up from nerve cell activity. Together with his colleagues, Hans Knutsson solved that problem by using CCA, a mathematical analysis. Now, the team is in the middle of the next big challenge.
“In classic fMRI, the person being scanned must continuously follow set instructions, like moving a hand or solving a math problem. But with real-time fMRI, the situation can be changed interactively all the time”, Hans Knutsson explains.
Mats Andersson, himself a principal research engineer, is an experienced test subject. He calculates that he has spent at least 20 hours inside the machine, where he is exposed to a very powerful magnetic field – 1.5 tesla, or 50,000 times stronger than that of the earth.
“But I’m fine!” he says. “Magnetic fields are completely safe, as long as you don’t have any metal in there with you.”

As he lies in the tube that will lead him into the scanner, he puts on a head coil – an antenna that catches signals from the cerebral cortex – and a pair of 3D goggles. He is now connected to a loop, where his brain can work together with a computer to solve a problem.
Right now, Mats Andersson will use the loop to communicate in writing with another person at a computer terminal outside the scanner room. His goggles show him a virtual keyboard and a pointer that can be controlled from letter to letter by means of slight movements of the hand or foot. The system has been gradually refined so that, now, the mere thought of moving is enough for the pointer to obey.
A reply to the question “favourite food” emerges, letter by letter. P, A, N, C... pancake. A little shaky, but it works.

A possible application of this technique is to give patients who are totally paralysed a chance to communicate with the outside world. But, mainly, the real-time technology provides new opportunities for understanding how the brain works. It can also be used during brain surgery, thanks largely to LiU researchers developing a new way of visualising information.
“We first scan the brain for five minutes”, explains Anders Ynnerman, professor of scientific visualisation. “New algorithms help us to get better pictures with a greater depth than before. We then use the fMRI signal as a kind of lamp that lights up areas of activity. The light spreads out and casts shadows. We can also peel the brain apart, layer by layer, to see what is happening deeper inside.”
The result provides much better guidance for a surgeon than the traditional flat pictures, which show only the activity on the surface of the brain.

“Everyone gets excited over the new images, from radiologists to neuroscientists”, Ynnerman says. “All we need to do now is package the technology into user-friendly software.”
Volume visualisation is viable in many areas apart from medical applications. It can be used for simulating airflow around aeroplane wings, for finding defects in industrial materials, in archaeology and so on. It is basically the same method used in creating special effects in films, such as smoke and fire.