Cognitive and Neural Humor Processing: The influence of structural stimulus properties and Theory of Mind ANDREA C. SAMSON (c) Andrea C. Samson Dissertation zur Erlangung der Doktorwürde an der Philosophischen Fakultät der Universität Freiburg (Schweiz). Genehmigt von der Philosophischen Fakultät auf Antrag der Professoren Prof. Dr. Oswald Huber (1. Gutachter) Prof. Dr. Willibald Ruch (2. Gutachter) Freiburg, 10.12.2008, Prof. Dr. Jean-Michel Spieser, Dekan University of Fribourg http://e-thesis.unifr.ch for Boris Acknowledgments I would like to thank the following people who all contributed to this thesis either professionally or privately: My supervisor Prof. Dr. Oswald Huber has greatly supported my research and motivated me to pursue the interesting topic of this dissertation. I would like to thank particularly Dr. Stefan Zysset for his helpful support in brain research related questions. I would also like to express gratitude to Prof. Dr. Willibald Ruch and Dr. Christian F. Hempelmann for their helpful comments and fruitful discussions that supported and inspired my research. Many thanks to Elisabeth Rumo, Arlette Baer, Nadine Hilti, Yonni Meyer, Dr. Odilo Huber, PD Dr. Siegfried Macho, Dr. Michael Schulte (now: University of Bergen, Norway) and Eric Bourquard for their daily support at the Department of Psychology, University of Fribourg and Mareike Menz at the Max-Planck-Institute for Cognitive and Brain Sciences. A further thank you to the students who helped to collect data in numerous pre- examinations and all the participants that took part in my studies. Not to forget, Aurelia Annus for proofreading this thesis. Finally, for their continuous emotional support, I wish to thank Boris and my family. ii Table of Contents Acknowledgments.....................................................................................................................ii Abstract..................................................................................................................................... v Part I: Theoretical Background.............................................................................................. 1 1 Introduction ........................................................................................................................... 1 2 Humor and Humor Theories................................................................................................ 5 2.1 The concept of humor and humor theories....................................................................... 5 2.2 Cognitive Humor Theories............................................................................................... 7 2.3 Incongruity-resolution and nonsense humor.................................................................. 10 2.4 The General Theory of Verbal Humor........................................................................... 13 2.5 Implications from the GTVH for the present studies..................................................... 16 3 Interindividual differences in humor processing: Experience seeking .......................... 18 4 Empathy, Theory of Mind and Humor ............................................................................. 20 4.1 Theoretical considerations about empathy, Theory of Mind and Humor ...................... 20 4.2 Empirical studies on empathy, Theory of Mind and Humor.......................................... 22 5 Asperger Syndrome and Humor........................................................................................ 25 5.1 Autism and Asperger Syndrome .................................................................................... 25 5.2 Autism, Asperger Syndrome and Humor....................................................................... 26 6 Brain imaging studies on humor processing..................................................................... 29 7 Introduction into the method of functional Magnetic Resonance Imaging ................... 32 7.1 Physical basics of fMRI ................................................................................................. 34 7.2 Gradient-Echo ................................................................................................................ 35 7.3 The BOLD-phenomenon................................................................................................ 36 7.3.1 Spatial resolution................................................................................................... 38 7.3.2 Temporal course and resolution .......................................................................... 39 7.3.3 Regional and intersubjective variability ............................................................. 40 7.3.4 Additional biological and physiological limitations ........................................... 41 7.4 Analysis of fMRI data.................................................................................................... 41 7.4.1 Pre-processing........................................................................................................ 42 7.4.2 Spatial transformations ........................................................................................ 43 7.4.3 Statistical evaluation ............................................................................................. 44 7.5 Visualisation................................................................................................................... 46 8 Research questions .............................................................................................................. 47 8.1 Neural activation involved in pure incongruity-resolution (chapter 10)........................ 47 8.2 The influence of Logical Mechanisms on the neural humor response (chapter 10) ...... 48 iii 8.3 Neural correlates of incongruity-resolution and nonsense humor (chapter 11)............. 48 8.4 The influence of experience seeking on the neural response during humor processing (chapter 11) .......................................................................................................................... 49 8.4 The influence of empathizing and systemizing on cognitive and affective humor processing (chapter 12) ........................................................................................................ 49 Part II: Studies ....................................................................................................................... 52 9 An overview on cartoon research ...................................................................................... 52 10 Cognitive humor processing: different logical mechanisms in non-verbal cartoons— an fMRI study................................................................................................................... 53 11 Neural correlates of incongruity-resolution and nonsense humor in relation to experience seeking............................................................................................................ 85 12 The influence of empathizing and systemizing on humor processing: Theory of Mind and humor....................................................................................................................... 120 13 General Discussion .......................................................................................................... 152 14 References ........................................................................................................................ 164 List of Abbreviations............................................................................................................ 190 List of Figures....................................................................................................................... 192 List of Tables......................................................................................................................... 195 iv Abstract The aim of the present dissertation is to broaden the knowledge of cognitive humor processes that are the basis of humor appreciation through a multidisciplinary approach: psychological as well as cognitive-linguistic humor theories were taken into account. The focus of interest lies mainly on the incongruity-resolution step of humor processing in relation to structural properties of humorous stimuli as well as individual differences in experience seeking, empathy and systemizing skills. Neuronal correlates—measured by means of functional Magnetic Resonance Imaging (fMRI)—as well as several behavioral measures were used: questionnaires, rating scales as well as explanations of the punch line. Three central themes were addressed: 1) cognitive and affective processes (particularly incongruity-resolution) of visual humorous material, i.e., non-verbal cartoons, 2) the influence of structural properties such as Logical Mechanisms (LMs), as well as incongruity-resolution vs. nonsense humor on neuronal correlates of humor processing, and 3) the relationship between Theory of Mind and humor—Theory of Mind as stimulus characteristic (what cognitive skills are required in order to understand the punch line correctly) and as mental ability (and closely related to empathy) that can vary within subjects. The results revealed the following network to be involved in incongruity-resolution without pre-processing steps: ventro-medial prefrontal cortex, inferior frontal gyrus, temporo- parietal junction (TPJ) and supramarginal gyrus. The rostral cingulate zone—an area known to be involved in conflict monitoring and error processing—was