Part I of this two-part paper provided a broad overview of clinical and experimental findings bearing on the neural correlates of conscious processes. It was argued that several neurocognitive models related to: orienting to the outer world, dream sleep, and the integration of sensory-motor representations, converge upon a core ‘conscious system’, dubbed the extended reticular-thalamic activating system . The functions of the ERTAS, which shares extensive projections with the cerebral cortex, are mostly ‘implicit’, in contrast to the explicit representation of (...) conscious content within the neocortex. Part II expands this ERTAS model to encompass: the generation of coherent patterns of EEG activation, the integration of distributed cortical processes into a stream of unified percepts , and selective attention, as well as links between the ERTAS and systems providing the neural substrates for episodic memory and volition. (shrink)

A broad consensus has developed in recent years in the cognitive and neurosciences that the cognitive functions of the mind arise out of the activities of an extensive and diverse array of specialized processors operating as a parallel, distributed system. A theoretical perspective is presented which expands upon this "society" model to include globally integrative infuences upon this arrary of processors. This perspective serves as the basis for an explicit neural model of a "global workspace within a system of distributed (...) specialized processors". Anatomical and physiological evidence are reviewed which suggest that this parallel, modular architecture is superceded by a more diffuse, tangential intracortical network capable of integrating underlying modular activites into increasingly global cognitive representations. There follows an explication of the role of this "neural global workspace" in providing the essential basis for the central control of attention and the generation of unified, conscious percepts. Finally the role of thalamic and brainstem activation systems in these integrative processes is discussed. (shrink)