New methods for brain research

Novel methods of measuring magnetic fields outside the head give further insights to the functioning of the human brain. In his doctoral thesis “Estimating Neural Currents from Neuromagnetic Measurements”, Kimmo Uutela developed new methods for finding electrical activity of the brain, which enable easier identification of different brain areas. The Finnish Association of Graduate Engineers (TEK) and the Engineering Society in Finland (TFiF) honoured Uutela’s work with their joint doctoral thesis award.

Uutela developed two methods, based on magnetic measurements, for estimating electric activity of the brain. Research was carried out at the Low Temperature Laboratory of Helsinki University of Technology. One method is a multidipole model applying genetic algorithms and the other is a minimum current estimate method. These mathematical methods make it easier to locate brain areas which operate simultaneously, and are useful tools for research purposes as well as for the planning of neurosurgery, for example.

“Both estimation methods are automatic making the source estimation faster and less subjective,” explains Uutela. “Also, the results of the minimum current estimate are in a format that can be easily combined with results of other brain imaging modalities and over different subjects.”

Errors caused by head movements can be corrected using a third method which records movements of the head during measuring, and uses this information to amend estimations of the neural currents. “The head movement correction enables accurate measurements on subjects that do not keep still during the experiment, especially children,” notes Uutela. The correction method, useful in research as well as in pediatric clinical studies, has been developed in collaboration with the Finnish company Neuromag Ltd, but is not yet commercially available.