Neuronal reflections and subjective awareness
For a neuroscientist working under the assumption of a complete correspondence between mind and brain, conscious awareness poses a profound mystery. It is a unique phenomenon in which a state of a physical system – i.e. a distributed pattern of neuronal activity is inexplicably transformed into an absolutely private and internal mental experience. Thus, the relevant point of view that needs to be taken when considering neuronal mechanisms underlying phenomenal experience must also be intrinsic – that of the brain’s neurons themselves. In contrast, the perspective taken by most neuroscience research examines neuronal activity from an external observer perspective. Here I will conjecture that the intrinsic perspective is implemented in the brain through rapid and recurrent neuronal activity – local neuronal “ignitions”. In this dynamics, the information about the state of a local neuronal assembly is distributed back to the neurons that form the assembly through recurrent activations. A conscious percept emerges when, through these neuronal reflections, the ambiguity inherent in the activity of isolated neurons is converted into a unique and meaningful assembly state. The rapid distribution of assembly information necessitates high firing rates, sustained activity, and dense local connectivity. All these conditions fit nicely with recent experimental findings. The fourth consequence – the founding of conscious awareness on local reverberatory activity – is still highly controversial – and should be viewed, at this stage, as a prediction of the local “ignition” hypothesis.