Jonathan C. W. Edwards

Giving an account of the relation between evolution and consciousness is painted as posing a dilemma between panpsychism, with minimal consciousness in every grain of matter, and radical emergence, with consciousness appearing as from nowhere in living structures. Panpsychism has been seen as suffering from a combination problem and radical emergence as unjustified in physics. The underpinning of physics now lies in field theory, which may provide a way out on both sides. Only, and always, in a field theory account do influences at different points in spacetime combine in the same indivisible event. Radical emergence is also inherent to field theory. Moreover, by providing rich patterns of influence involving both discrete identities and quantitative values, field theory might provide a basis for sensed propositional meaning with subjects and predicates. Ordered condensed matter within living tissue may support unusual emergent dynamic units uniquely suited to building representations of the world with sensed meaning. The evolution of consciousness may then be seen as a tractable biological problem centred on increasingly sophisticated ways for external world dynamics to be mirrored by internal representations with semantic content, based in field relations within condensed matter with genetically encoded complex order.

McFadden has recently raised several cogent points about the problems of 'Gestalt Information' and the meaning of meaning in human experience, in particular the central problem of 'binding'. Very reasonably, he has tried to resolve these problems in terms of a unified electromagnetic field. However, certain premises on which his arguments are based are open to question. Of these, two deserve particular note. The claim that individual neurons only have access to a tiny number of bits of information seems wrong, since neurons have up to 50,000 independent inputs. The basic claim that the brain has a single unified EMfield that could explain the richness of experience is also open to doubt. Taken together with related issues these points suggest that the role for EM fields in meaningful human experience may be more in line with conventional neurophysiology--at the level of post-synaptic integration.

Conscious experience has been said to be outside of, or alien to, physics, and unexplained in a physical world. However, it is argued here that experience is entirely expected in a physical world that can only be defined by its power to determine patterns of experience. Something physical is something with the type of causal power that can contribute to determining the content of an experience if a subject is present at the right place and time. Physical powers also interact with other physical powers, distant from any given subject, to form chains, and it is these interactions that physics handles mathematically. Nevertheless, actual causation is always defined by reference to determination of experience. The apparent puzzle of why there should be a link between experience and the physical may relate in part to the fact that experience is always immediately causally proximal, always 'here and now', at least as far as we can ascertain. Proximality, and with it the potential for mentality, cuts across existential/ ontological categories. Experience also requires a concept of an intrinsic individual, in order for there to be individual points of view. The practical problem for consciousness studies is to identify intrinsically individual causal units with event domains in human brains, that can have points of view and content that could fit with human experiences, in a way consistent with current physics. It is suggested that the 'causal diamond' concept of the here and now explored by Savitt (2015) and Arthur (2019), together with principles of field theory, may provide a useful starting point.

It is proposed that a human conscious experience of the sort we report to each other reflects a direct causal interaction between a pattern of information about the world, encoded in a field of postsynaptic potentials, and a quantized mode of excitation occupying dendritic cytoskeleton. The requirement for a quantized account is seen simply as the need for an event of experience to be a single indivisible, but richly patterned, causal relation between information and an 'informee'. It is argued that the informee is likely to be a higher-order quantized collective mode (much as proposed by Craddock and colleagues, 2017) with the biologically relevant dynamics likely also to be describable in classical terms. No specific interpretation of quantum theory is needed. In this scenario, anaesthetics would abrogate reportable experience by detuning parameters underpinning cytoskeletal informee modes, perhaps critically increasing associated impedence. It is also proposed that tuning and detuning of informee modes in individual dendritic trees by binding of accessory proteins to cytoskeleton plays a physiological role in short-term memory and truth evaluation through ascertainment of sequential signal pattern consonance. Components of this model may be involved in cellular adaptive responses in many types of organism.

In defining physical (i.e. causal dynamic) units to which conscious experience is to be ascribed, integrated information theory (IIT) raises three notable requirements: (1) that a unit to which consciousness is ascribed must be defined, or circumscribed, by some intrinsic aspect or property, where intrinsic implies existing 'for itself' or 'from its point of view'; (2) that the intrinsic aspect that defines the unit to which consciousness is ascribed must be dynamic (i.e. involve causal power) rather than purely structural or kinematic; (3) that this dynamic aspect must involve the integration of elements of information in such a way that semantic values of elements are interdependent, allowing rich meaning. It will be argued that, although these requirements are all well-motivated, IIT falls short on them within a testable natural science framework. Concerns raised about the three requirements all point towards one central problem: that the concept of 'integrated information' does not involve any specific causal relation. Although IIT starts from strictly causal premises, the final analysis appears to invoke two incompatible accounts of the same events, with 'integration' having no causal relational basis. It will also be argued that the way IIT attempts to provide a testable theory of dynamic units to which consciousness is ascribed mustcausal reason inherent in any means of testing, be at best redundant for in the human case and, as a general principle, untenable.

Nature Network Groups hosted an invited workshop on 'Theories of Consciousness' during the second semester of 2009. There were presentations by each of 15 authors active in the field, followed by debate with other presenters and invitees. A week was allocated to each of the theories proposed; general discussion threads were also opened from time to time, as seemed appropriate. We offer here an account of the principal outcomes. It can be regarded as a contemporary, 'state of the art' snapshot of thinking in this field.

We perceive colour, shape, sound and touch 'bound together' in a single experience. The following arguments about this binding phenomenon are raised: (1) The individual signals passing from neurone to neurone are not bound together, whether as elements of information or physically. (2) Within a single cell, binding in terms of bringing together of information is potentially feasible. A physical substrate may also be available. (3) It is therefore proposed that a bound conscious experience must be a property of an individual cell, not of a group of cells. Since it is unlikely that one specific neurone is conscious, it is suggested that every neurone has a version of our consciousness, or at least some form of sentience. However absurd this may seem it appears to be consistent with the available evidence; arguably the only explanation that is. It probably does not alter the way we should expect to experience the world, but may help to explain the ways we seem to differ from digital computers and some of the paradoxes seen in mental illness. It predicts non-digital features of intracellular computation, for which there is already evidence, and which should be open to further experimental exploration. The arguments given may well prove flawed or the conclusion biologically or physically untenable, but the idea is raised for discussion not least because a formal demonstration that it is invalid may help to identify more fruitful avenues

It is argued that both neuroscience and physics point towards a similar re-assessment of our concepts of space, time and 'reality', which, by removing some apparent paradoxes, may lead to a view which can provide a natural place for consciousness and language within biophysics. There are reasons to believe that relationships between entities in experiential space and time and in modern physicists' space and time are quite different, neither corresponding to our geometric schooling. The elements of the universe may be better described not as 'particles' but as dynamic processes giving rise, where they interface with each other, to the transfer, and at least in some cases experience, of 'pure'or 'active'information, the mental and physical just reflecting different standpoints. Although this analy-sis draws on general features of quantum dynamics, it is argued that purely quantum level events (and their 'interpretations') are unlikely to be relevant to the understanding of consciousness. The processes that might be able to give rise, within brain cells, to an experience like ours are briefly reviewed. It is suggested that the elementary signals that are integrated to generate a spatial experience may have features more in common with words than pixels. It is further suggested that the laws of integration of words in language may provide useful clues to the way biophysical integration of signals in neurons relates to integration of elements in experiential space.