University of Pennsylvania
The neural mechanisms of strategic competition: a cross-species comparison
Competitive social interactions, as in chess or poker, often involve multiple moves and countermoves deployed tactically within a broader strategic plan. Such maneuvers are supported by mentalizing or theory-of-mind (ToM)—reasoning about the beliefs, strategic tendencies, and goals of an opponent. The neuronal mechanisms underlying strategic competition has remained largely unknown, partially due to the lack of behavioral paradigms that can effectively test social competition in multiple species with varying levels of ToM. In this talk, I will introduce a virtual soccer game (penalty kick) featuring continuous competitive interactions, and present behavioral, neural, and computational data collected over several years in non-human primates as well as distinctive groups of human subjects. Players of both species displayed broadly similar strategies, namely unpredictability in trajectory and precision in last-move timing for kickers, and responsiveness for goalies. Further, the penalty kick game also quantified and differentiated the tactical competence across different human populations. We used Gaussian Process (GP) classification to decompose continuous gameplay into a series of discrete decisions predicated on the evolving states of self and opponent. We then extracted relevant model parameters as regressors for analysis of neuronal activity in macaque mid-superior temporal sulcus (mSTS), the putative homolog of human temporo-parietal junction (TPJ) an area selectively engaged during strategic social interactions. We discovered two spatially-segregated populations of mSTS neurons that signaled movements of self and opponent, sensitivity to state changes, and previous and current trial outcomes. Finally, inactivating mSTS reduced kicker unpredictability and impaired goalie responsiveness. Together these findings lend further functional support to the hypotheses that mSTS is the simian homolog of human TPJ, and that multi-level intentional reasoning in humans has its origins in abstract computations supporting strategic social interactions in nonhuman primates.
A pizza lunch will be served. Please bring your own beverage.