MD, PhD, Adj. professor of Diagnostic Radiology
Radiologist, specialized in neuroradiology
Department of Radiology,
Oulu University Hospital, POP 50, 90029 Oulu, Finland
I was the first European to detect spontaneous brain activity fluctuations independently in 1997 as a young rascal scientist in a resting brain imaged with fMRI in Oulu. My teachings from high school physics special course proved correct: one always needs to calibrate the measuring tool prior to measurement. To me in fMRI this meant calibrating the base"line" activity of the brain without task, since task is often statistically compared to this "resting state". After obtaining FFT power spectral tool from PhD Jarkko Oikarinen & Jukka Jauhiainen in a day my eyes started seeing slowly fluctuating waves instead of steady baselines.
While still a PhD student, I was drafted by connectivity pioneer Bharat Biswal to MCW, USA where I learned original resting state analytics. After this experience I became a pioneer in developing several methods for detecting spontaneous brain activity sources, most of them stemming from collaboration with MCW in addition to Oulu MIRG members. My most important work so far was the use of independent component analysis (ICA) in separating functional brain cortices from spontaneous brain activity, first announced in ISMRM 2001. This was made possible by joint ventures between my roommate Jussi Kantola and Aapo Hyvärinen, who is the developer of FastICA.
After 2005 the resting state scanning and analysis became the fastest growing neuroimaging realm, which can also be seen on my citation number graph below. After the surge of the resting state imaging I’ve had the privilege to give several invited talks in HBM and ISMRM conferences on resting state from then on. We've analysed clinical and birth cohort populations but mostly we've been interested in basic physiological phenomena related to brain function. We've shown with Juuso Nissilä's group that the inborn neuronal and vascular wall (Terakita, PNAS 2013) opsins mediate neuronal interactions with light. Recently we've detected new mechanisms of glymphatic brain pulsations and shown a method how to measure blood-brain barrier opening with a simple Dc-EEG device.
I envision the human mind as water in my research, sometimes like throbbing mist and sometimes raging sea that goes seven times down, eight times up.