Work for this dissertation was conducted at the HUS Medical Imaging Center and the BioMag Laboratory at the Helsinki University Central Hospital. The MEG recordings on surgical patients were performed at the Low Temperature Laboratory at the Helsinki University of Technology and the intraoperative measurements were performed at the Department of Neurosurgery at the Helsinki University Central Hospital.
I wish to express my gratitude to Professors Carl-Gustaf Standertskjöld-Nordenstam and Leena Kivisaari at the Department of Radiology as well as the CEO of the Helsinki Medical Imaging Center, Docent Juhani Ahovuo for the opportunity to conduct my studies and for the access to the medical imaging facilities at the Helsinki University Central Hospital. I am thankful to Professor Riitta Hari, Head of the Brain Research Unit, and Professor Mikko Paalanen, Head of the Low Temperature Laboratory, for our collaboration with the Low Temperature Laboratory. Professor Riitta Hari greatly helped me to get initial funding for my work.
I wish to thank the pre-examiners of my Thesis, Professors Risto Kauppinen and Iiro Jääskeläinen for their helpful and constructive comments on this Thesis.
My supervisors, Professor Hannu Aronen, Professor Risto Ilmoniemi and Docent Juha Huttunen supported me with their own special expertise. I was especially inspired by the can-do spirit of Professor Aronen when we were struggling to setup functional MRI in the Helsinki University Central Hospital. From Professor Risto Ilmoniemi I learned a lot about setting high standards for scientific work along with the principles of magnetoencephalography. Docent Juha Huttunen provided me invaluable insights into the physiology of the sensorimotor system. His advice and suggestions in manuscript drafting were very valuable.
Many individuals have contributed to the studies of this Thesis. Especially I want to thank Dr. Heidi Wikström. With her I took my first steps in MEG and acquired data for the first two studies. I want to also thank Docent Anna-Maija Seppäläinen for her support and collaboration in the initial phase of my work for the Thesis.
Dr. Eero Salli’s input in image and signal processing was crucial in accomplishing the three last studies. Dr. Hanna Pohjonen’s contribution in this field was vital as well. I am grateful to Professors Ari Visa and Toivo Katila for their collaboration in the third study. Dr. Leena Lauronen, Dr. Matias Palva and Mr. Sami Martinkauppi helped in
Dr. Erika Kirveskari played a key role together with Dr. Sari Avikainen in performing MEG experiments for the patients in the final study of the Thesis. She also made the intracranial recordings together with Dr. Tero Kovalainen and Professor Juha Jääskeläinen. Collaboration with Professor Juha Jääskeläinen was essential for the realisation of the final study. I also wish to express my gratitude to Docent Jyrki Mäkelä, Docent Nina Forss and Mr. Mika Seppä, members of the CliniMEG team at the Low Temperature Laboratory, who were involved in the final study. I am indebted to Dr. Antti Brander with whom I performed the fMRI studies on the neurosurgical patients and with whom I assessed the results.
The work for this Thesis started almost simultaneously with the opening of the BioMag Laboratory. To work in a newly established laboratory has been exciting. I want to thank the present and former personnel of BioMag Laboratory for their support. Ms.
Suvi Heikkilä came several times into rescue when we were faced with problems during our experiments. In the early phases of this work the Neuromag personnel greatly helped in getting the MEG measurements going. Special thanks go to Dr. Petteri Laine who was a co-worker in our first study.
Without the support of Professor Risto Näätänen and the members of his research group it would have been very difficult for newcomers like me to get started with my work.
Docent Minna Huotilainen taught me in practice how to operate the MEG device. Dr.
Janne Sinkkonen was my tutor in scientific computing and taught me the basics of Linux system administration. Dr. Juha Virtanen was the electronics wizard who manufactured our fMRI compatible electric stimulator and numerous black boxes necessary for our experiments.
After our research group became part of the Helsinki Brain Research Center I received valuable support and advice from Professor Synnöve Carlson in many aspects of my work. I want to thank Professor Leena Laasonen and Docent Oili Salonen, the former and the present head of the Functional Imaging Unit of Helsinki Brain Research Center, for all their support for our work.
During my work I spent several years working at the BioMag Laboratory and Department of Radiology at the Helsinki University Central Hospital. I want to thank all the researcher colleagues for a pleasant working atmosphere and collaborative attitude. I want to especially thank Docent Kirsi Lauerma, Dr. Vadim Nikuline, Dr. Klaus Linkenkaer-Hansen and Dr. Päivi Ryynänen, the colleagues with whom I have shared
members of the Functional Brain Imaging Unit, for their collaboration. I am grateful to Dr. Veli-Pekka Poutanen for his support with MR system operation.
Foremost, I want to thank my wife Tita for her love and support. Her patience has been remarkable, though my Thesis must at times have felt like a never-ending project. My children, Elisa, Lauri and Leo, brought me back to the reality and sometimes even beyond it when I became carried away by science. They have given me a frame of reference, which has helped me to see things in the right proportions. My deepest thanks to them as well.
This work was financially supported by the Finnish Cultural Foundation, the Maud Kuistila Memorial Foundation, the Maire Taponen Foundation, the Pehr Oscar Klingendal Foundation, the Radiological Society of Finland, the Finnish Cancer Organisations, the Clinical Research Institute Helsinki University Central Hospital, the Helsinki University Central Hospital research funds, the European Union 5th framework programme (Contract No:QLK3-CT-1999-00894), and the Academy of Finland.
Espoo, December 2006,
Antti Korvenoja