Do neural correlates of consciousness cause conscious states?

Abstract

Neural correlates of consciousness (NCCs) have been defined as neural systems and states of those systems, which are correlated with certain states of consciousness and which are minimally sufficient for these states of consciousness to occur. Here, it is discussed whether based on the identification of a NCC one may claim that this neural correlate causes the corresponding state of consciousness. In a strict sense, neural states and corresponding states of consciousness should occur simultaneously according to the definition of NCCs. However, two causally related events should occur consecutively in time according to the general view. Thus, within the NCC framework the question of a causal psychoneural relationship is only valid under the premise of a small and practically unobservable time shift between neural states and corresponding states of consciousness. The term causality is usually applied either in the sense of efficient causation or in the sense of explanatory causation. Efficient causality addresses the physical relation of two events and the criterion of an energy exchange between both events. Explanatory causality, on the other hand, refers to the law-like character of the conjoined occurence of two events. Under a dualistic point of view, the interpretation that neural states effectively cause consciousness would not be justified, since effective causation, as understood in physical sciences, should be associated with energy transfer. But such an energy transfer between the domain of consciousness and the neural domain would violate presently accepted physical laws. Therefore, it is argued that one may state that neural states cause states of consciousness only in the broad sense of explanatory causality with regard to the observation of a law-like psychoneural relation. Within the viewpoint of identity theory, however, one would rather claim that certain states of consciousness basically are neural states.