I am in Vancouver, Canada now. I am here for a transit on the way back to Tokyo.
The ASSC 2010 conference in Toronto was very interesting. Here's my abstract. I could have many helpful discussions with my colleagues.
Only Time will tell: On the nature of free will.
Key words time, consciousness, free will
The contingency between sensory inputs and motor outputs is one of the crucial aspects of the neural mechanism underlying the phenomenology of consciousness. For example, the nature of subjective time is known to be affected by the contingency between voluntary action and sensory feedback (Haggard et al. 2002). The perception of self body is affected by the contingency between actions and sensory feedbacks, as demonstrated in the mirror box treatment of phantom limbs (Ramachandran et al. 1995). Various empirical evidences suggest that sensori-motor contingency affects the construction of the phenomenal self in its temporal and embodied dimensions.
One important and arguably ultimate question regarding human consciousness is that of free will. The question concerning the nature of free will is an essential one not only from theoretical point of view but also from the social implications involved (e.g. from the point of view of neuroethics, Gazzaniga 2005). In that free will concerns itself with the movement of the body in time, it is necessary to consider its nature in the context of sensori-motor contingency. From the phenomenological point of view, neural processes involved in action can be regarded as a subset of those involved in intentional processes in general.
Here I argue that the nature of free will can be properly treated only by taking subjective time into consideration. Only a consideration of the nature of subjective time will tell us the origin of the feeling of free will, when it is taken to be compatible with determinism (Dennet 2003). I present a model of subjective time based on the interaction between sensory and intentional processes in the brain, in which two kinds of simultaneity ("sensory simultaneity" and "intentional simultaneity") are defined.
Using the model, I analyze the differential nature of neural circuits involved in sensory and motor processes, based on the anatomical data on human brain (e.g., Van Essen 2004). Finally, I give an account of the neural correlates of free will in terms of the "open-ended" structures of intentional simultaneity in subjective time, in the context of the topology of connectivity in the cortical neural network.