Publication 4254

Consciousness has many different connotations, some of which are amenable to treatment within neurobiological description systems while others are not. It is possible to define in neurobiological terms the brain states associated with conscious-ness. It is also conceivable that neurobiology will ultimately provide a reductionistic explanation of mechanisms which enables the brain (1) to construct from the sparse and diverse signals of its sensors coherent models of its environment, including the or-ganism itself, and to generate abstract descriptions, (2) to iterate the same strategy to monitor its own states, thereby generating meta descriptions, (3) to weigh the combined results of these analyses in order to reach decisions and to generate adapted behavioural responses, and (4) to communicate through various channels at different levels of ab-straction the results of these cognitive processes to other brains. Since it became clear that the concept of the Cartesian theatre is untenable, that processes in the brain are highly distributed and that there is no single convergence center where the results of the numerous parallel operations are brought together for joint interpretation and decision making, analysis of processes that are in principle amenable to neurobiological explanation is in itself a major challenge. \\Problems of different nature are encountered if one attempts a reductionistic explanation of the subjective connotations of consciousness associated with self-awareness, attributes that are assessed by introspection and by extrapolation from one’s own awareness of mental states to that of others. I shall defend the position that these aspects of consciousness cannot be understood as emergent properties of individual brains alone but come into existence only through communication among brains whose cognitive abilities must be sufficiently developed to generate a theory of mind, i.e. to generate models of presumed states of the respective other brain. Thus, self-awareness and the ability to experience sensations as subjective reality would have to be considered as cultural achievements or, and this is equivalent, as the result of experiencing dialogues of the kind: “I know that you know that I know.” Hence, these aspects of consciousness come into existence only through a social learning process in which brains experience a class of mental phenom-ena that emerge only from mutual reflection. These phenomena are ontologically different from those qualified above as amenable to direct neurobiological investigation because unlike the latter they are the result of a dialogue among brains that got in-creasingly refined during cultural evolution. This is probably the reason why these phenomena appear as not deducible from analysis of individual brains in the same way as one can analyse the neuronal substrate of pattern recognition, memory or motor con-trol. My proposal is that the phenomena that give rise to the so called “hard problems” in the philosophy of consciousness, problems resulting from the ability to be aware of one’s own brain functions can be understood as emergent properties of brains without having to take a dualistic position; however, because these phenomena have a social or cultural origin and hence both a historical and interpersonal dimension, they cannot be understood as an emergent property of an isolated brain alone and hence transcend the reach of conventional neurobiological approaches.