Cortical Correlates of Language Perception. Neuromagnetic Studies in Adults and Children

JYVÄSKYLÄ STUDIES IN EDUCATION, PSYCHOLOGY AND SOCIAL RESEARCH 314 Tiina Parviainen Cortical Correlates of Language Perception Neuromagnetic Studies in Adults and Children JYVÄSKYLÄN YLIOPISTO JYVÄSKYLÄ STUDIES IN EDUCATION, PSYCHOLOGY AND SOCIAL RESEARCH 314 Tiina Parviainen Cortical Correlates of Language Perception Neuromagnetic Studies in Adults and Children Esitetään Jyväskylän yliopiston yhteiskuntatieteellisen tiedekunnan suostumuksella julkisesti tarkastettavaksi yliopiston Villa Ranan Blomstedtin salissa lokakuun 15. päivänä 2007 kello 12. Academic dissertation to be publicly discussed, by permission of the Faculty of Social Sciences of the University of Jyväskylä, in the Building Villa Rana, Blomstedt Hall,, on October 15, 2007 at 12 o'clock noon. UNIVERSITY OF JYVÄSKYLÄ JYVÄSKYLÄ 2007 Cortical Correlates of Language Perception Neuromagnetic Studies in Adults and Children JYVÄSKYLÄ STUDIES IN EDUCATION, PSYCHOLOGY AND SOCIAL RESEARCH 314 Tiina Parviainen Cortical Correlates of Language Perception Neuromagnetic Studies in Adults and Children UNIVERSITY OF JYVÄSKYLÄ JYVÄSKYLÄ 2007 Editors Tapani Korhonen Department of Psychology, University of Jyväskylä Irene Ylönen, Marja-Leena Tynkkynen Publishing Unit, University Library of Jyväskylä Cover Picture by Tiina Parviainen Brain Image Courtesy of Mika Seppä URN:ISBN:9789513930844 ISBN 978-951-39-3084-4 (PDF) ISBN 978-951-39-2943-5 (nid.) ISSN 0075-4625 Copyright ©2007 , by University of Jyväskylä Jyväskylä University Printing House, Jyväskylä 2007 ABSTRACT Parviainen, Tiina Cortical correlates of language perception – neuromagnetic studies in adults and children Jyväskylä, University of Jyväskylä, 2007, 129 p. (Jyväskylä Studies in Education, Psychology, and Social Research, ISSN 0075-4625; 314) ISBN 978-951-39-3084-4 (PDF), 978-951-39-2943-5 (nid.) Yhteenveto: Kielen käsittely aivoissa – neuromagneettisia tutkimuksia aikuisilla ja lapsilla Diss. The end product of language perception, accessing meaning, is a result of complex computation in the human brain and presumably reflects analysis at, and transformation between, various levels of representation. In this thesis, MEG was used to characterize those representations at the neural level in adults and children. The special acoustic nature of speech was reflected in auditory cortical activation at 100 ms after sound presentation. In dyslexia, cortical organization of auditory processing, in general, was disrupted in this same time window (Study I). Meaning-based analysis of speech started at around 250 ms and was induced also by meaningless utterances, particularly when acoustic- phonetic or contextual cues predicted continuation as a word (Study IV). For complete spoken words, influence of sound form (phonology) appeared in neural activation within 250 ms, followed by neural signatures of semantic processing (Study V). Cortical activation to speech and print was similar in children and adults as regards location. However, activation sensitive to linguistic information was delayed and prolonged in children as compared with adults. Importantly, it was correlated with behavioral skills, indicating interdependence between maturing neural processes and developing linguistic skills (Studies II and III). In adults, conversion from letter to sound, an essential process in reading, engaged the superior temporal cortex. Activation increased with letter-string length, particularly with non-words (Study VI). This thesis provides new insights into the question of how mature and developing cortical circuits support the challenging but apparently effortless task of language perception and comprehension. Keywords: Speech perception, speech comprehension, reading, neuroimaging, magnetoencephalography, N100, N400 Author’s address Tiina Parviainen Brain Research Unit Low Temperature Laboratory Helsinki University of Technology, Finland P.O.Box 2200 02015 TKK, Finland E-mail: [email protected] Supervisor Academy Professor Riitta Salmelin Brain Research Unit Low Temperature Laboratory Helsinki University of Technology, Finland Reviewers Docent, Professeur Associée Elisabet Service Department of Psychology University of Helsinki, Finland Département de psychologie Université de Montréal, Canada Professor David Poeppel Department of Linguistics Department of Biology University of Maryland, Washington, USA Opponent Professor David Poeppel Department of Linguistics Department of Biology University of Maryland, Washington, USA ACKNOWLEDGEMENTS This work was carried out in the Brain Research Unit of the Low Temperature Laboratory within Helsinki University of Technology. I would like to thank all the people who made it possible for me to work in this inspiring environment. I’m grateful to the head of the laboratory, Prof. Mikko Paalanen, for providing the research facilities and for his support throughout my work. I also had the possibility to meet the former head, Academician Olli Lounasmaa, who had a major impact in creating this interdisciplinary unit with its high scientific ambitions. I am very grateful to the head of the Brain Research Unit, Prof. Riitta Hari, for her friendly support and interest to my work and for providing an open-minded and creative environment for research. I am deeply indebted to my supervisor, Prof. Riitta Salmelin, who has guided me into the world of MEG with highest expertise and detail. She has had the most important impact on my work in LTL with admirable enthusiasm and systematic research approach. I would like to express my warmest gratitude to Dr. Päivi Helenius, who has patiently and kindly advised me with all the questions in scientific work. Her thorough and productive contribution has been of invaluable importance for this thesis. I am deeply grateful to my former supervisor Prof. Heikki Lyytinen at the Department of Psychology in the University of Jyväskylä, for a crucial contribution in my first steps into brain research during my undergraduate studies. His encouragement and support has been important throughout my PhD work. My interest in the field of neuroscience really started during my internship in the Neurological Department, Jyväskylä Central Hospital. I wish to warmly thank Ms. Ritva Hänninen, Ms. Kaija Poutanen and Mr. Pekka Kuikka, for introducing me to the mysterious and fascinating functions of the human brain. I sincerely thank Prof. David Poeppel and Doc. Elisabet Service, for their valuable comments and suggestions on the manuscript of this thesis. I also would like to warmly thank Dr. Hanna Renvall, Mr. Topi Tanskanen and Mr. Lauri Parkkonen for useful comments and Dr. Jane Erskine for correcting my English. I am grateful to Dr. Ritva Paetau and Prof. Heikki Lyytinen, who formed my follow-up group, for insightful discussions during the thesis work. I wish to express my gratitude to all my co-authors, Dr. Milene Bonte, Dr. Päivi Helenius, Ms. Kaisa Hytönen, Ms. Marianne Inkinen, Prof. Pekka Niemi, Dr. Elisa Poskiparta, Ms. Johanna Vartiainen and Prof. Taeko Wydell for inspiring collaboration. It has been a pleasure to work with all of you. The most important impact both for the general atmosphere and for my personal well-being in the laboratory has been provided by the fellow students at the LTL. I am especially grateful to my long-time room-mate Timo Saarinen for providing a clear-sighted perspective and a pleasant company for everyday work. I also want to sincerely thank Topi Tanskanen, Hanna Renvall, Lauri Parkkonen and Jan Kujala for always being there when needed – be it a neuroscientific, technical, statistical, psychological, philosophical, or personal issue. Our discussions have given me valuable insights into my work and, when needed, fully detached me from brain research. I sincerely thank Johanna Vartiainen for her contagious positive attitude. Big thanks to the whole social group! The value of getting to know you is way above this bunch of papers. I wish to thank all the past and present colleagues in the Brain Research Unit for the supportive and expert environment in the laboratory. I sincerely thank Maarit Aro, Sari Avikainen, Gina Caetano, Katri Cornelissen, Nina Forss, Nobuya Fujiki, Liisa Helle, Linda Henriksson, Jaana Hiltunen, Yevhen Hlushchuk, Annika Hulten, Matti Hämäläinen, Antti Jalava, Ole Jensen, Veikko Jousmäki, Juha Järveläinen, Jaakko Järvinen, Marika Kaksonen, Ken-Ichi Kaneko, Marita Kattelus, Erika Kirveskari, Hannu Laaksonen, Satu Lamminmäki, Sari Levänen, Martin Lehécka, Mia Liljeström, Sasu Liuhanen, Sanna Malinen, Seppo Mattila, Jyrki Mäkelä, Jussi Numminen, Miika Pihlaja, Marjatta Pohja, Antti Puurula, Tommi Raij, Tuukka Raij, Ville Renvall, Miiamaaria Saarela, Stephan Salenius, Ronny Schreiber, Martin Schürmann, Mika Seppä, Teija Silen, Cristina Simões-Franklin, Jaana Simola, Sini Sipponen, Päivi Sivonen, Linda Stenbacka, Antti Tarkiainen, Samu Taulu, Kimmo Uutela, Simo Vanni, Nuutti Vartiainen and Minna Vihla. I also wish to thank Flamine Alary, Sandra Smeets and all the other visitors who have contributed to the atmosphere of the LTL. I am grateful to Mr Helge Kainulainen, Doc. Peter Berglund, Ms. Teija Halme, Ms. Marja Holmström, Ms. Pirjo Kinanen, Ms. Tuire Koivisto, Ms. Satu Pakarinen, Ms. Liisi Pasanen and Ms. Leena Meilahti for being patient with me and always helping me with practical issues. I owe big thanks also to Ms. Raija Mehto at University of Jyväskylä for all her help in my PhD studies, especially within the final stage. I am especially grateful to Ms Mia Illmann for her help in the MEG-measurements and to Mr. Samuli Hakala, Mr.

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