MIT Press, 1999 Review by Paul Bohan Broderick, Ph.D. on May 26th 2002 Volume: 6, Number: 21.

An exploration is given of neural network features now being uncovered in cortical processing which begins to go a little way to help bridge the ''Explanatory Gap'' between phenomenal consciousness and correlated brain activity. A survey of properties suggested as being possessed by phenomenal consciousness leads to a set of criteria to be required of the correlated neural activity. Various neural styles of processing are reviewed and those fitting the criteria are selected for further analysis. One particular processing style, in (...) which semiautonomous and long-lasting cortical activity ''bubbles'' are created by input, is selected as being the most appropriate. Further experimental criteria are used to help narrow the possible neural styles involved. This leads to a class of neural models underpinning phenomenal consciousness and to a related set of testable predictions. (shrink)

The relation between mind and matter is considered in terms of recent ideas from both phenomenology and brain science. Phenomenology is used to give clues to help bridge the brain-mind gap by providing constraints on any underlying neural architecture suggested from brain science. A tentative reduction of mind to matter is suggested and used to explain various features of phenomenological experience and of ownership of conscious experience. The crucial mechanism is the extended duration of the corollary discharge of attention movement, (...) with its gating of activity for related content. Aspects of experience considered in terms of the model are the discontinuous nature of consciousness, immunity to error through misidentification, and the state of 'pure' consciousness as experienced through meditation. Corollary discharge of attention movement is proposed as the key idea bringing together basic features of meditation, consciousness and neuroscience, and helping to bridge the gap between mind and matter. (shrink)

There are now various approaches to understand where and how in the brain consciousness arises from neural activity, none of which is universally accepted. Difficulties among these approaches are reviewed, and a missing ingredient is proposed here to help adjudicate between them, that of ''perspectivalness.'' In addition to a suitable temporal duration and information content of the relevant bound brain activity, this extra component is posited as being a further important ingredient for the creation of consciousness from neural activity. It (...) guides the development of what is termed the ''Central Representation,'' which is supposed to be present in all mammals and extended in humans to support self-consciousness as well as phenomenal consciousness. Experimental evidence and a theoretical framework for the existence of the central representation are presented, which relates the extra component to specific buffer working memory sites in the inferior parietal lobes, acting as attentional coordinators on the spatial maps making up the central representation. The article closes with a discussion of various open questions. (shrink)

The "relational mind" approach to the inner content of consciousness is developed in terms of various control structures and processing strategies and their possible neurobiological identifications in brain sites. This leads naturally to a division of consciousness into a passive and an active part. A global control structure for the "single strand" aspect of consciousness is proposed as the thalamo-nucleus reticularis thalami-cortex coupled system, which is related to experimental data on the electrical stimulation of awareness. Local control, in terms of (...) excitatory transfer from pre-processing sites to posterior working memory regions, is supported by data on subliminal perception timing and disambiguation of poorly defined percepts. The inner content of consciousness is understood as arising from the resulting relational features between inputs and stored pre-processing and episodic memories. Strong analogies are drawn between emergent properties of the model and suggested properties of "raw feels", supporting the thesis that working memories are the initial sites for the emergence of phenomenal awareness, and the frontal lobes for its further adumbration in terms of higher cognitive processing, including the creation of self. (shrink)

This paper explores a remarkable convergence of ideas and evidence, previously presented in separate places by its authors. That convergence has now become so persuasive that we believe we are working within substantially the same broad framework. Taylor's mathematical papers on neuronal systems involved in consciousness dovetail well with work by Newman and Baars on the thalamocortical system, suggesting a brain mechanism much like the global workspace architecture developed by Baars (see references below). This architecture is relational, in the sense (...) that it continuously mediates the interaction of input with memory. While our approaches overlap in a number of ways, each of us tends to focus on different areas of detail. What is most striking, and we believe significant, is the extent of consensus, which we believe to be consistent with other contemporary approaches by Weiskrantz, Gray, Crick and Koch, Edelman, Gazzaniga, Newell and colleagues, Posner, Baddeley, and a number of others. We suggest that cognitive neuroscience is moving toward a shared understanding of consciousness in the brain. (shrink)

The approach of Revonsuo is criticised as being based on a misplaced emphasis on coupled oscillatory dynamics, as well as on too limited an approach to recent advances in brain imaging. This results in the nature of attention as a basic component in consciousness being ignored, and prevents any attempt to attack the crucial problem for consciousness of inner experience: of ‘what it is like to be’.

The basic postulate that consciousness arises from stable states of recurrent activity is shown to need considerable modification from our current knowledge of the neural networks of the brain. Some of these modifications are outlined.