A MATHEMATICAL MODEL OF BIOFEEDBACK
AND ITS RELATION TO NEURAL ACTIVITY
C. Nishimura*, L-Q. Wang**, A. Nagase*, K. Terada* and Y. Miyamoto***
*Toho University School of Medicine, Tokyo, Japan
**Research Center for Advanced Technologies, Tokyo Denki University, Tokyo, Japan
***Department of Mechanical Engineering, Osaka Sangyo University, Osaka, Japan
nishimuc@med.toho-u.ac.jp
Abstract: Biofeedback is an acquisition technique of self-regulation ability of a biological function, of which we are normally unaware, through a series of training aided by an additional outer feedback pathway. We proposed a mathematical model of biofeedback in which a learning system on the conscious level learns characteristics of a subconscious regulation system corresponding to the biological function. When the learning converges, the learning system itself becomes an inverse system of the regulation system. Then, if a regulation command is put to the learning system on the conscious level, it drives the regulation system strictly following the command without the outer feedback pathway, which enables voluntary control of the biological function. Based on the model, we measured neural activities relating to a phenomenon of state alteration of consciousness in the course of training in search for an appropriate connection between the learning system and the target regulation system. The situation was modelled as an interpretational change in depth of an ambiguous stereogram. Functional MRI measurement revealed neural activities in bilateral prefrontal area. The results show an important role of neural activities in the prefrontal area in connecting the learning system with the appropriate subconscious regulation system.