Date: Wed, June 20, 16:00-18:00 Place: Room M203, Komaba Open Laboratory, The University of Tokyo Invited Speaker: Mr. Sergey S. Tarasenko (Kyoto University) Title: A Hypothesis of Chaotic Dynamics underlying Decision-Making without Prior Information Abstract: In our previous studies, the non-random performance of decision-making without prior information (Blind Choice) has been indicated. This performance is well described by the Golden Ratio and its numerical properties through out experimental conditions. Therefore we have suggested existence of some common mechanism for the Blind Choice. In this paper, we discuss a new numerical method to study this mechanism. The basic idea behind this method is assumption of dynamical system employed for decision-making. The main result obtained using the method is extraction of a specific space describing the system's structures. Here we focus on the organization of this space's structure which is performed in accordance with interaction of repelling and attracting fixed point deployed across the space. These results suggest that mental information processing underlying the Blind Choice is based on a chaotic system. This system and the Golden Ratio are hypothesized to be contained in Implicit Primordial Knowledge.