2014年03月17日　　15:00 〜 16:00

CiNet B1F Seminar room

Shinsuke Suzuki

Affiliation of Shinsuke Suzuki
Division of the Humanities and Social Sciences, California Institute of Technology
JSPS Postdoctoral Fellow, Graduate School of Letters, HokkaidoUniversity

Abstract:

Consensus formation is a hallmark of human and animal societies and potentially offers various advantages (e.g. reduction of risk from predators, enhancement of decision accuracy etc). Yet, little is known about how human consensus arises from interactions among group members.
In the present study, we investigated dynamics of human consensus decision-making and the underlying neural mechanisms. We scanned 20 subjects using fMRI while they tried to reach consensus with the other group members. By model-based analyses on behavioral and fMRI data, we elucidated three key variables in human consensus decision making:
subjects’ own preference represented in a core of valuation-related brain network, ventromedial prefrontal cortex; group members’ previous choice encoded in so-called mentalizing-related regions, temporo-parietal junction and dorsomedial prefrontal cortex; and estimation of the others’ tenaciousness/stubbornness processed in inferior parietal lobule. These findings suggest that an inference about others’ hidden mental-traits (e.g., tenaciousness) plays an important role in human consensus formation, orchestrated with a valuation process and a simple response to the others’ past action.