Wirkuttis Nadine, Ohata Wataru, Tani Jun
Cognitive Neurorobotics Research Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son 904-0495, Okinawa, Japan.
Entropy (Basel). 2023 Jan 31;25(2):263. doi: 10.3390/e25020263.
This study explains how the leader-follower relationship and turn-taking could develop in a dyadic imitative interaction by conducting robotic simulation experiments based on the free energy principle. Our prior study showed that introducing a parameter during the model training phase can determine leader and follower roles for subsequent imitative interactions. The parameter is defined as w, the so-called meta-prior, and is a weighting factor used to regulate the complexity term versus the accuracy term when minimizing the free energy. This can be read as sensory attenuation, in which the robot's prior beliefs about action are less sensitive to sensory evidence. The current extended study examines the possibility that the leader-follower relationship shifts depending on changes in w during the interaction phase. We identified a phase space structure with three distinct types of behavioral coordination using comprehensive simulation experiments with sweeps of w of both robots during the interaction. Ignoring behavior in which the robots follow their own intention was observed in the region in which both ws were set to large values. One robot leading, followed by the other robot was observed when one w was set larger and the other was set smaller. Spontaneous, random turn-taking between the leader and the follower was observed when both ws were set at smaller or intermediate values. Finally, we examined a case of slowly oscillating w in anti-phase between the two agents during the interaction. The simulation experiment resulted in turn-taking in which the leader-follower relationship switched during determined sequences, accompanied by periodic shifts of ws. An analysis using transfer entropy found that the direction of information flow between the two agents also shifted along with turn-taking. Herein, we discuss qualitative differences between random/spontaneous turn-taking and agreed-upon sequential turn-taking by reviewing both synthetic and empirical studies.
本研究通过基于自由能原理进行机器人模拟实验，解释了在二元模仿互动中领导者 - 追随者关系和轮流机制是如何发展的。我们之前的研究表明，在模型训练阶段引入一个参数可以确定后续模仿互动中的领导者和追随者角色。该参数定义为w，即所谓的元先验，是一个加权因子，用于在最小化自由能时调节复杂度项与准确度项。这可以理解为感觉衰减，即机器人对动作的先验信念对感觉证据不太敏感。当前的扩展研究考察了在互动阶段领导者 - 追随者关系是否会根据w的变化而转变的可能性。我们通过在互动过程中对两个机器人的w进行扫描的全面模拟实验，确定了具有三种不同类型行为协调的相空间结构。在两个w都设置为较大值的区域中，观察到机器人忽略自身意图的行为。当一个w设置得较大而另一个设置得较小时，观察到一个机器人引领，另一个机器人跟随。当两个w都设置为较小或中间值时，观察到领导者和追随者之间自发的、随机的轮流。最后，我们研究了在互动过程中两个智能体之间w以反相缓慢振荡的情况。模拟实验导致了轮流，其中领导者 - 追随者关系在确定的序列中切换，同时伴随着w的周期性变化。使用转移熵的分析发现，两个智能体之间的信息流方向也随着轮流而转变。在此，我们通过回顾综合研究和实证研究，讨论随机/自发轮流与商定的顺序轮流之间的定性差异。
