Takashi Ikegami is a professor in the Department of General Systems Sciences at the University of Tokyo. His works encompasses both the arts and sciences and deal with complex systems and artificial life. He received his doctorate in physics from the University of Tokyo in 1989. His research is centered on complex systems and artificial life, a field that aims to build a possible form of life using computer simulations, chemical experiments, and robots. Some of these results were published in the book Life Emerges in Motion in 2007. Takashi Ikegami frequently attends the International Conference on Artificial Life, and gave the keynote address at the 20th Anniversary of Artificial Life conference in Winchester, UK. He is also a member of the editorial boards of Artificial Life, Adaptive Behavior, BioSystems, and Interaction Studies.
Froese T. Iizuka H. & Ikegami T. (2014) Embodied social interaction constitutes social cognition in pairs of humans: A minimalist virtual reality experiment. Scientific Reports 4: 3672. https://cepa.info/1012
Scientists have traditionally limited the mechanisms of social cognition to one brain, but recent approaches claim that interaction also realizes cognitive work. Experiments under constrained virtual settings revealed that interaction dynamics implicitly guide social cognition. Here we show that embodied social interaction can be constitutive of agency detection and of experiencing another’s presence. Pairs of participants moved their “avatars” along an invisible virtual line and could make haptic contact with three identical objects, two of which embodied the other’s motions, but only one, the other’s avatar, also embodied the other’s contact sensor and thereby enabled responsive interaction. Co-regulated interactions were significantly correlated with identifications of the other’s avatar and reports of the clearest awareness of the other’s presence. These results challenge folk psychological notions about the boundaries of mind, but make sense from evolutionary and developmental perspectives: an extendible mind can offload cognitive work into its environment. Relevance: This paper builds on an enactivist approach to cognition (Varela et al.).
Froese T., Woodward A. & Ikegami T. (2013) Turing instabilities in biology, culture, and consciousness? On the enactive origins of symbolic material culture. Adaptive Behavior 21(3): 199–214. https://cepa.info/6358
It has been argued that the worldwide prevalence of certain types of geometric visual patterns found in prehistoric art can be best explained by the common experience of these patterns as geometric hallucinations during altered states of consciousness induced by shamanic ritual practices. And in turn the worldwide prevalence of these types of hallucinations has been explained by appealing to humanity’s shared neurobiological embodiment. Moreover, it has been proposed that neural network activity can exhibit similar types of spatiotemporal patterns, especially those caused by Turing instabilities under disinhibited, non-ordinary conditions. Altered states of consciousness thus provide a suitable pivot point from which to investigate the complex relationships between symbolic material culture, first-person experience, and neurobiology. We critique prominent theories of these relationships. Drawing inspiration from neurophenomenology, we sketch the beginnings of an alternative, enactive approach centered on the concepts of sense-making, value, and sensorimotor decoupling.
Open peer commentary on the article “Homeostats for the 21st Century? Simulating Ashby Simulating the Brain” by Stefano Franchi. Upshot: Using the example of chemical oil droplets, the paper discusses the idea of a homeostat in terms of a default mode network.
Ikegami T. & Suzuki K. (2008) From a homeostatic to a homeodynamic self. Biosystems 91(2): 388–400.
Life as an autonomous homeostatic system is discussed. A mechanism that drives a homeostatic state to an autonomous self-moving state is examined with two computational cell models. The mechanism is met with Ashby’s ultrastability, where random parameter searching is activated when a system breaks a viability constraint. Such a random search process is replaced by the membrane shape in the first model and by chaotic population dynamics in the second model. Emergence of sensors, motors and the recursive coupling between them is shown to be a natural outcome of an autonomous homeostatic system.
Sato Y., Iizuka H. & Ikegami T. (2013) Authors’ Response: From Bodily Extension to Bodily Incorporation. Constructivist Foundations 9(1): 89–92. https://constructivist.info/9/1/089
Upshot: In the model simulation and the human experiment, we observed that attention shifted from a tool to a task. This was accompanied by bodily extension. However, our experiments lack a sense of bodily incorporation (the sense of ownership. Based on the valuable commentaries, we would like to discuss the necessary conditions for possible bodily incorporation in terms of redundant degrees of freedom, synchronous visual tactile stimulation, and 1/f noise.
Sato Y., Iizuka H. & Ikegami T. (2013) Investigating Extended Embodiment Using a Computational Model and Human Experimentation. Constructivist Foundations 9(1): 73–84. https://constructivist.info/9/1/073
Context: Our body schema is not restricted to biological body boundaries (such as the skin), as can be seen in the use of a cane by a person who is visually impaired or the “rubber hands” experiment. The tool becomes a part of the body schema when the focus of our attention is shifted from the tool to the task to be performed. Problem: A body schema is formed through interactions among brain, body, tool, and environment. Nevertheless, the dynamic mechanisms underlying changes in the body schema are still not fully understood. Method: To study the changing conditions of the body schema (e.g., a shift of attention), a simulation model of object discrimination was extended to differentiate between two kinds of sensitivities – sensitivity to an object being directly manipulated and sensitivity to another object being manipulated by the first. The proposed model consisted of windmills with different numbers of vanes. A model agent was required to determine the number of vanes on a windmill by touching the vanes blindly with an arm controlled by a neural network. Placing a second windmill beside the first and gearing the two windmills to move associatively resulted in the agent using the first windmill as a tool with which to discern the number of vanes on the second windmill. In other words, an agent’s body schema can shift from its arm tip to the boundary between the first and second windmills. We then introduced an experiment with a real windmill model to test the hypothesis demonstrated by the theoretical model. Results: We demonstrated that even simple computational agents can have two different sensitivities to the windmills. One agent becomes sensitive to the first windmill and insensitive to the second one. Another agent becomes insensitive to the first windmill and sensitive to the second one by using the first one as a tool. Therefore, we concluded that the boundary of the body schema was extended to the first windmill in the case of the latter agent because paying attention to the task to be performed instead of the tool itself is essential for the tool to be considered as part of the body schema. Analysis of the experiments using a computational model and human experimentation revealed that a shift from an irregular to a regular movement of a windmill is an indication of extension of the body schema. Constructivist content: Our insights are beneficial for enactive cognitive science. This is because an extended body schema questions the Cartesian separation between subject and object, and the self and the environment.