Abstract

Whether consciousness is unidimensional with states defined along a single scale or it consists of multiple fundamental dimensions has been debated. Clinical assessment of consciousness distinguishes the content of consciousness (awareness) and the level of consciousness (wakefulness or arousal), which conflates firstperson phenomenal properties with third-person observable properties. The state of consciousness is more appropriately defined in terms of subjective level and content which are interdependent. On this account, the state of consciousness is exclusively defined by the experienced mental content, i.e.awareness, whereas behaviour and cognition are overt expressions of the state. Wakefulness and arousal are predisposing factors for specific forms of conscious experience. Nevertheless, a unidimensional representation of consciousness fails to account for the variety of qualitatively different experiences in both normal and altered states of consciousness. To overcome this problem, cognitive and abstract multidimensional models of consciousness have been proposed, but such dimensions are interdependent and lack axiomatic support. A novel multidimensional characterization of consciousness based on the brain's macroscale functional geometry provides an alternative, empirically grounded model whose dimensions are defined by neurofunctional rather than behavioural attributes. The state of consciousness is then represented as a point in this functional multidimensional space.