SCUOLA INTERNAZIONALE SUPERIORE DI STUDI AVANZATI INTERNATIONAL SCHOOL FOR ADVANCED STUDIES Social cognitive and neural mechanisms of food choice under the influence of food-related information Candidate Pin-Jane Chen Supervisors Prof. Raffaella Rumiati & Dr. Francesco Foroni Thesis submitted for the degree of Philosophiæ Doctor in Cognitive Neuroscience at International School for Advanced Studies, Trieste, Italy Academic Year: 2017/2018 1 Acknowledgement “Every story has an end, but in life every ending is just a new beginning.” I would like to thank my supervisor, Professor Raffaella Rumiati, for bringing me to this wonderful city and to the interesting field of study. With her guidance and support, my new life has started with a lot of unforgettable experiences. I also would like to thank my co-supervisor, Dr. Francesco Foroni, for his continuous advice and knowledge sharing regardless of time and space. Their supervisions helped me in all the time of research and writing of this thesis. I would like to express my gratitude to the committee members: Professor Anne Roefs, Professor Giorgia Silani, Professor Mathew Diamond, and Professor Alessandro Treves, for reviewing my thesis and giving me insightful comments. Their feedback incented me to improve and to widen my research. Thanks my colleagues in iNSuLa Lab for the kind suggestions about working and warm sharing about living. I could not complete my work without the help of Sinem, Carol, Tiziano, and Sofia. To my dear friends at SISSA, especially Xuan, Katarina, Diletta, and Miriam, friends in Trieste, and friends in Taiwan: I cannot go through these days without your company, understanding, and tolerance. Thank you for being with me for the journey, I cherish every moment we spent together. Last but not least, my beloved families in Taiwan and in Trieste, you mean to me so much, thank you for your unconditioned and unlimited love and support. 2 Table of Contents Abstract ..................................................................................................................................................................... 8 CHAPTER 1 General Introduction .................................................................................................................. 11 1.1 Importance of food choices for well-being ........................................................................................ 11 1.2 The influence of socio-psychological constructs on food choice .................................................... 13 1.3 Cognitive determinants of food choice: implicit and explicit associations ................................ 14 1.3.1 Measurements of implicit/explicit associations towards food ....................................................... 15 1.3.2 Predictive validity of implicit and explicit associations toward food choice ............................... 17 1.4 Changing food choice: strengthening implicit and explicit associations towards food .......... 17 1.4.1 Evaluative Conditioning (EC) ............................................................................................................. 18 1.5 Neural mechanism underlying food associations, food choice, and changing food choice .... 20 1.5.1 Neural correlates of food associations and food choice ................................................................ 20 1.5.2 Changing food choice and its neural correlates .............................................................................. 24 1.6 Motives and objective of the present PhD project ........................................................................... 26 CHAPTER 2 Study 1: Is coffee fancier than Tea? Changing choice of drinks by changing implicit associations between drinks and social status through evaluative conditioning. ................................... 28 1. Introduction .............................................................................................................................................. 28 1.1 Social and psychological constructs of interest associated to commonly consumed drinks (e.g. Tea and Coffee) ............................................................................................................................. 29 1.2 Measuring implicit and explicit associations towards drinks and food ..................................... 30 1.3 Predictive validities of implicit and explicit associations towards drink and food choices ... 31 1.4 Changing the associations in order to improve drink and food choices .................................... 32 1.5 Objectives of Study 1 ............................................................................................................................. 32 2. Experiment 1: Associations between Tea/Coffee and socio-psychological constructs ............. 33 2.1 Methods .................................................................................................................................................... 33 2.1.1 Participants and Procedure ............................................................................................................ 33 2.1.2 Stimuli ................................................................................................................................................ 33 2.1.3 Implicit measurements: IAT and SP .............................................................................................. 34 2.1.4 Explicit measurement ...................................................................................................................... 36 3 2.1.5 Choice Task....................................................................................................................................... 36 2.2 Results ....................................................................................................................................................... 36 2.2.1 Implicit measurements: IAT and SP .............................................................................................. 36 2.2.2 Explicit measurements ..................................................................................................................... 37 2.2.3 Prediction of choice ......................................................................................................................... 38 2.2.4 Correlation between measurements .............................................................................................. 38 2.3 Discussion on Experiment 1 ................................................................................................................. 39 3. Experiment 2: Changing implicit associations between Tea and social status to influence the choice of Tea.............................................................................................................................................. 40 3.1 Methods .................................................................................................................................................... 40 3.1.1 Participant and Procedure ............................................................................................................. 40 3.1.2 Experimental Tasks ......................................................................................................................... 40 3.1.3 Data analyses ................................................................................................................................... 41 3.2 Results ....................................................................................................................................................... 42 3.3 Discussion on Experiment 2 ................................................................................................................. 43 4. General discussion of Study 1 ............................................................................................................... 43 5. Conclusion of Study 1 ............................................................................................................................. 46 CHAPTER 3 Study 2: Change your mind before you choose! Neural correlates of changing food associations. ............................................................................................................................................................ 47 1. Introduction .............................................................................................................................................. 47 1.1 Processed food and its role in the diets ................................................................................................... 47 1.2 Changing food choice through associative learning paradigm .................................................... 48 1.3 The associative learning paradigm: Evaluative conditioning ...................................................... 49 1.4 Neural mechanism underlying food choice and change of food choice ..................................... 51 1.5 Individual characteristics/eating habits and change of food associations ................................. 52 1.6 Objectives of Study 2 ............................................................................................................................. 54 2. Methods ...................................................................................................................................................... 55 2.1 Material and Methods ..........................................................................................................................