Mind-Brain Lecture: "Assessing strategic risk with fMRI"
Speaker Giorgio CORICELLI (CNRS Lyon)
Date 27 May 2010, 18:30
Location >>> FESTSAAL (Berlin School of Mind and Brain, second floor, Luisenstraße 56, Haus 1, 10117 Berlin)
Organized by Annette Winkelmann
We used fMRI to measure the neural correlates of strategic uncertainty in games and lotteries. Participants played a series of stug hunt games, entry games, and lotteries. The two games differ in their equilibrium
properties: stug hunt games are games of strategic complementarity (e.g., an investment pays off if and only if a sufficient number of agents invest in the same industry, so all invest and nobody invest are two Nash
equilibria) while entry games are of strategic substitutability (e.g., if too many agents invest in a new market all get nothing; here we should not all do the same, but instead choose mixing strategies in equilibrium). A
mentalizing network (mPFC, TPJ, STS, precuneus) is activated in games playing vs. Lotteries, thus distinguishing the social and the private nature of the choice context. Furthermore, we found a behavioral
correlation and a similar pattern of activity in the striatum between choosing lotteries and choosing the stug hunt game; while insula and lateral OFC activity was mainly related to entry games choices.
Interestingly, we found a clear separation of insula activity in lotteries and stug hunt games when distinguishing between risk averse and risk loving players. However, in entry games this distinction is not at all found. We conclude that the entry game creates more strategic uncertainty as predicted by the nature of the theoretical equilibrium which also involves levels of reasoning. While the strategic uncertainty of the stug
hunt game can be ‘reduced’ to standard risk, the uncertainty underlying entry games is higher and analogous to ambiguous choices.
Dr Giorgio Coricelli, Centre de Neurosciences Cognitives, Institut des Sciences Cognitives , http://www.isc.cnrs.fr/sir/CVCoricelli2007.pdf