CBBM Lecture "Modelling complex multistep reward-based decisions and social learning about other persons’ character traits" by

Dr. Christoph W. Korn,

Institute for Systems Neuroscience,

University Medical Center Hamburg-Eppendorf

will take place on Tuesday, December 4, 2018 from 15:00 to 16:00 hours in CBBM, Ground Floor, Seminar Room B1/B2.

Host: Prof. Sören Krach
Department of Psychiatry and Psychotherapy
University of Lübeck


Social interactions pose many challenges for human decision-making and learning. Here, I focus on two pertinent aspects: First, many social encounters require decisions between uncertain alternatives for the near and far future. Second, getting to know another person entails learning the character traits of that person. However, formal models that adequately capture the neuro-cognitive mechanisms of such complex decision-making and learning processes are lacking.

In the first part of the talk, I will present a series of partly published studies that show how humans combine optimal and heuristic policies to maximize rewards in non-social multistep decision scenarios. Results obtained from behavioral modelling and functional neuroimaging suggest a role of the medial prefrontal cortex in the computation of the employed policies and of the uncertainty associated with relying on these policies. To conclude the first part of the talk, I will discuss the relevance of these findings for multistep decisions in social contexts.

In the second part of the talk, I will describe unpublished experiments that outline how humans update their estimation of other persons’ character traits (e.g., how polite, helpful, and reliable is another person?). The best-fitting models combine principles derived from reinforcement learning algorithms with participants’ world knowledge about the distributions and interrelations of different character traits. Re-analyses of a published functional neuroimaging dataset show that these interrelations between character traits are represented in the medial prefrontal cortex.

Taken together, the to-be-presented projects aim at providing neuro-computational accounts of decision-making and learning processes that are integral to successful social cognition.


Christoph has recently been awarded an Emmy-Noether research group on the topic “Human cooperation: A multimodal approach” and will start this group at the Institute of Systems Neuroscience (University Medical Center Hamburg-Eppendorf, UKE) in December 2018. Within the last two years, he has worked at the same institution in the group of Jan Gläscher within the Transregional Collaborative Research Center on Crossmodal Learning. Additionally, he has collaborated with Martin Nowak and Alex McAvoy at Harvard University thanks to co-funding by the German Academic Exchange Service.

Before, he did a postdoc at the University of Zurich in the group of Dominik Bach and completed a PhD at the Freie Universität Berlin in the group of Hauke Heekeren with funding from the Berlin School of Mind and Brain. During a joint Master’s program by University College London, Ecole Normale Supérieure, Paris, and Université Pierre et Marie Curie, Paris, he worked in the group of Ray Dolan under the supervision of Tali Sharot. He holds a Bachelor’s degree in biomedicine from the University of Würzburg.