|Biophysics of Consciousness is the first book to elucidate the biophysical basis of consciousness.|
Roman R. Poznanski
Roman R. Poznanski is a biological theoretician and a leading authority on modeling in the neurosciences. He is a co-author of the bestseller Mathematical Neuroscience (Academic Press, 2013) where he develops theories in neuroscience with mathematics. A prolific writer he has written papers in prestigious high impact ISI-indexed neuroscience journals, including the Journal of Integrative Neuroscience: a transdisciplinary journal that combines theories of information handling in the brain with experimental brain research.
His main contribution to research began on the modeling of retinal neurons in visual perception with W.R.Levick, FRS from the John Curtin School of Medicine, Australian National University in Canberra. His modeling work was first to predict the locus of retinal direction selectivity in individual dendritic branches of starburst amacrine cells in the retina in 1990 (and published in 1992). He subsequently developed a more accurate model of a starburst amacrine cell in order to show how direction-selectivity is produced by a network of these cells. The unification of the yet unknown subcellular model of retinal direction selectivity with starburst network topology remains one of his current research themes together with Amane Koizumi of the National Institute for Physiological Sciences, Okazaki, Japan. In particular, on establishing the topology underlying a presynaptic scheme of directional selectivity, he proposed an acetylcholine (ACh) model of directionally selective starburst amacrine cells (Poznanski, R.R. Cellular Inhibitory Behavior Underlying the Formation of Retinal Direction Selectivity, J. Integr. Neurosci. 9, 299-335, 2010). Although experimental studies have shown that during retinal development (prior to vision) the assembly of retinal cholinergic network connections are 'eliminated' in which the glutamatergic networks are formed, such studies categorically do not rule out the possibility of the 'eliminated' ACh connections reconnecting after vision takes place in the mature retina. A model of the inner plexiform layer is currently missing from any prototype bionic eye giving only rudimentary vision to the blind.
His other research direction has been on the establishment of a new generation of neural networks, in particular, the biophysical foundations of neural network theory (as embodied in his book, Biophysical Neural Networks, Mary Ann Liebert, 2001). He was the first to reveal how microscopic-level biophysical properties (e.g., endogenous structures, ion channels; neuronal geometries) may be explicitly incorporated into an analytical formalism that predicts mesoscopic-level functionality. This approach has two major advantages: (1) avoids entirely the mathematical errors and uncertainties inevitable in iterative computational models that necessarily discretize time and space; (2) provides a framework for generating complete and exact solutions for network output enabling dynamical continuity to be reflected through spatiotemporal patterns as a field of influence for dynamic cognitive processes. This led him to consider more sophisticated artificial systems, like the 'cognitive' brain-computer interface (embodied in the book, Modeling in the Neurosciences: From Biological Systems to Neuromimetic Robotics, CRC Press, 2005) .
He has spent years in research at the interface of neuroscience and mathematical modeling with particular emphasis on developing neuronal models across scale. His recent collaboration with Ivan Lazarevich (Institute of Applied Physics, RAS) and Dorian Aur (Stanford University, CA) focuses on the development of a new cable theory for understanding the precise effect of protein polarization on membrane potential and on the excitability process. In particular the non-stereotype action potentials are the result of molecular conduction. The new theory finds its true foundations in Maxwell's theory of the electromagnetic field. In classical Nernst-Planck theory, the membrane has no structure and therefore, any attempt at combining the dynamics described by time-dependent Nernst-Planck equation for the spatial distribution of ionic concentration with cable theory is fortuitous. Ionic current flow based on Maxwellian approach is not physico-chemical and currents caused by concentration gradients are neglected. However, this new cable theory of protein polarization approximates electrodiffusion in physico-chemical systems, and is comparable with, yet resilient to the epistemological limitations inherent in the classical Hodgkin-Huxley system. It was Hodgkin who said: “electrodiffusion is like a flea hopping in the storm” meaning that ionic current flow in the presence of an electric field has no coherency compared with an action potential, but Hodgkin never envisaged ionic current flow as a propagating 'shock wave' or non-stereotyped action potential.
It was Huxley who in 1959 suggested that a subthreshold disturbance can be initiated by numerically solving Hodgkin-Huxley equations, but these subthreshold oscillations as envisaged by Andrew F. Huxley in the 1950s are not the only subthreshold responses. Subthreshold oscillations do not have a rapid leading-edge reminiscent of a 'shock wave' for memory selection. Roman R. Poznanski has embarked on the physics of memory and how it depends on: (i) changes in protein metabolism accompanying learning; (ii) memory trace formation and storage (consolidation) in assemblies at the subcellular level through phosphorylation; and (iii) memory selection through dendritic protein polarization by subthreshold membrane potentials at the subcellular level. The prevalent hypothesis is that memory is sub-served by modulation in gene expression.
Mathematical Neuroscience is the first book on the development of a nonlinear functional analysis to better understand the intricate fallacies of methodological reductionism in neuroscience
He has also embarked on a research collaboration with Stanislaw Brzychczy (AGH University of Science and Technology) on the development of a nonlinear analysis methods to better understand the intricate fallacies of methodological reductionism in neuroscience. One recent example of this research is the application of nonlinear functional analysis to the cable equation proving that discrete models of neurons like 'multicompartmental models and spiking model neurons' are both dynamically implausible representations of real neurons. This research has implications to 'multi-scale' modeling that are supposed to be ultra 'realistic' attempts at modeling the brain. One limitation is that such 'multi-scale' models are incapable of harnessing 'bridges' across scale without producing a false sense of biological reality. This is because compartmentalization and/or discretization is subject to dynamical misalignment. All research based on compartmental methods should be treated with skepticism. The results of compartmental modeling to explain complex dynamical phenomena must be taken with a grain of salt. Infinite systems represent hierarchical levels in a way that will not delude the continuous dynamics of neuronal systems across spatiotemporal scales.
| Drs. Masumi Ishikawa, Roman Poznanski, and Chee Peng Lim. At far right, Dr. Jonathan Chan.|
Discussion on higher brain function at a meeting in Kuala Lumpur.
He has advised several graduate students: (1) Hiroshi Yamamoto 1996 M.Sc. “Computer Simulation of Bipolar Cell Coupling in the Teleost Retina,” Faculty of Information Sciences, Toho University, Japan; (2) Tirad Almalahmeh 2009 Ph.D. "Directional Selectivity by Network of Starburst Amacrine Cells in Retina", Faculty of Computer Science and Information Technology, University of Malaya, Malaysia; (3) Seyed Maysam Torabi 2010 M.Sc. "Noisy Cables", Faculty of Computer Science and Information Technology, University of Malaya, Malaysia; (4) Chan Siow Cheng 2013 Ph.D. "Neural Activity in a Morris-Lecar Population Density Model", Faculty of Engineering and Science, UTAR, Malaysia; (5) Nur Shafika Abel Binti Razali 2014 Ph.D. "Solitons in Neurons", School of Mathematical Sciences, USM, Malaysia
|Roman Poznanski with Dr. Jafri (Director and Consultant Neurosurgeon, Department of Neurosciences, USM)|
He is an advocate of the Bohmian (David Bohm) interpretation of quantum mechanics and the understanding of brain science through a dichotomy of implicate order and explicate order. This approach is based on realists attempt at interpreting quantum mechanics by distinguishing the epistemological aspect from the ontological aspect of Heisenberg’s uncertainty principle.
Shannonian information theory as a foundational basis of computational neuroscience corresponds to the explicate order and is therefore limited in our understanding of higher brain functions and consciousness that corresponds to the implicate order. Consequently, one begins to move beyond principles of information theory to explore how the result of unpredictable, nonlinear interactions among billions of neurons depends on what Karl Popper defined as interactionism. In this sense, cybernetics, computation, information theory, information science, information integration and information processing have no intrinsic value in elucidatin higher brain functions and consciousness that fall under the umbrella of interactionism. Consequently, to explain how brain dynamics generates consciousness, a different perspective is required from the cybernetic/computational/informational theory and/or information processing paradigm.
In computational neuroscience, reductionist approaches span multiple levels of neural organization; however in integrative neuroscience, each level is seamlessly sculptured as part of a continuum of levels. In other words, integrative neuroscience supports nonreductive physicalism. Reductionism assumes a direct causal relationship between a molecular/cellular mechanism and a behavioral phenomenon, ignoring the constraints that higher-level properties exert on the possible functions of that mechanism. One of these constraints is dynamic continuity which is intrinsically difficult to harness computationally because compartmentalization and/or discretization is subject to dynamical misalignment, producing a false sense of biological reality. Integration depends on dynamic continuity, which is selected by the electric field inside neurons and across synapses that results in a field of influence for augmenting uncognized processes in assemblies of networks. Current approximations to neural dynamics rely on multi-scale models through the doctrine of biological computation. An alternative approach is through relational biology where functional relations between neurobiological processes depend on hierarchical and functional integration in the brain. From this perspective, hierarchical integration is structural, bringing about hierarchical functional organization and a relational organization, while functional integration is adaptive enabling a self-referential organization to be mapped from functional interactions. By proposing a sound theoretical foundation via relational biology for studying biological organisation, Robert Rosen developed a rigorous theoretical foundation for living organisms as "anticipatory systems".
Physical laws are compounded by functional interactions to produce biological laws that only apply to animate matter. Unlike physical laws almost all biological laws are time-dependent and thus seem to appear as too accidental or transient to be named as 'laws' in the explicate order, but in the implicate order, the emergence of biological laws can differentiate between complex adaptive systems that evolved consciousness from machines with simpler mechanisms. For this reason, approaching biological organisms with reductionism sacrifices the whole in order to study the parts. The whole would not be recaptured once the biological organization had been destroyed. What makes living matter profoundly different from ordinary inorganic matter is the way in which each chemical reaction is coordinated with all the other for the good of the whole. This transcends explanatory physical laws and requires biological laws. As we know it, consciousness is invariably associated with life and therefore the notion of conscious robots is charlatanism because consciousness is not reproducible in silicon or any other nonliving matter, since the qualitative nature of consciousness prevents the quantification of consciousness. Artificial life reproduced as a brain in a supercomputer suffers from methodological reductionist issues that falsely reproduce the true workings of the biological organism.
Computational neuroscience defines loosely 'computations' as the mantra associated with functioning of the brain. What these ‘computations’ signify and portray are often mysterious mechanisms that are yet to be elucidated with precision. The central dogma of computational neuroscience is that it assumes information processing and Shannonian information theory to be modus operandi. Consequently, the field is often entwined with how a computer operates. Conversely, ‘selectionism’, 'integration', and 'dynamic continuity' define the essence of operations that are needed to elucidate higher brain function. However, it is now evident that 'computations' based on concepts from Shannonian information theory are irrelevant to how the brain integrates and selects dynamic continuity across scale.
The brain represents and processes information is a central dogma of computational cognitive neuroscience for 60 years.There are no representations in the neural circuitry of the brain, but physical interactions influenced by the electric field enable dynamic continuity to be entrained inside neurons and across synapses. No neural information processing, but rather selectionism manoeuvring dynamic continuity as an adaptive pressure from which semantics spontaneously emerge. The idea of neuroelectrodynamical coherence as the basis of dynamic continuity attempts to understand brain function on a system level through molecular physical interactions that underpins cognitive semantics, including conscious awareness.
Visual cortex is connected with the claustrum that serves the role of sensori integration relying visual information to most parts of the neocortex, but it is NOT the loci in the brain for consciousness. If it were then hydranencephalic children would be not self-aware. Decorticate animals groom, and feed quite well, in fact they are difficult to distinguish from intact ones. This is less the case in humans who are more dependent on the cortex for the execution of bipedal locomotion and fine motor control, of course not to mention language and communicable conscious awareness. Zapping deep in the brain with high frequency electric shocks would immediately shut down the corticoclaustral axons. Also the patient's brainstem and sub-cortical structures would be compromised. In hindsight, the claustrum is located in the cerebral cortex is not where consciousness resides in the brain, but rather it plays a vital role in sensori integration. A genuine case of abolition of consciousness is not loss of brain function through cortical sensori integration, but in the brain's total loss of energy. Conscious awareness as periodicities of energies is undoubtedly a precursor for self awareness. Moreover, it appears that a quantum event provides the switch for consciousness in order to explain how brain dynamics generates consciousness.
His most significant achievements include:
(i) First to pinpoint the locus underlying retinal direction selectivity in mammals, circa 1992. Through modeling starburst amacrine cells he was first to predict that direction selectivity is linked to their individual dendritic branches in a way that is still unknown with precision [5,6,13, 32].
(ii) First to show that conduction velocities in dendrites are nonconstant . This theoretical result showed that sparse distribution of ionic channels will determine how signals propagate differently in the dendrites of neurons as opposed to those in axons [21, 22].
(iii) First to find approximate analytical solutions to the Frankenhaeuser-Huxely equations [14, 38].
(iv) First to construct synaptically and gap-junctionally connected neural networks with ionic channels in dendritic cable structures. Such models have been applied to brain function through the development of large-scale brain cell assemblies [17, 23, 24, 27, 39, 40].
(v) First to introduce the conceptual idea that cognition is determined by how the distribution of endogenous proteins (e.g., ion channels) and synaptic inputs along the dendrites of neurons is integrated with the collective behavior of a large population of neurons grouped together as assemblies .
(vi) First to propose and develop nested neural network models for fMRI .
(vii) First to debunk the assumption of isopotentiality of small compartments (under 0.2λ) as a result of significant thermal noise .
(viii) First to propose a model-based framework for the development of a cognitive brain-computer interface .
(ix) Together with Brzycyhczy first to use functional analysis to prove how neural responses differ when continuous space is discretized in computational models [2,9].
(x) New theories of long-term memory away from synapses and dependent on ionic charge configurations [3,4].
(xi) First to elucidate the precise effect of protein polarization on membrane potential and on the excitability process through propagating subthreshold threshold shock waves that are conducive of rich-logic requirements in dendrites underlying memory selection .
(xii) First book in mathematical neuroscience that goes beyond unrealistic dynamics of physical abstractions into the realm of integrative modeling and dynamic continuity in spatiotemporal patterns [ Published].
(xiii) Genomic instantiation of consciousness in neurons through a biophoton field theory[Published].
(xiv) Co-edited together with Jack Tuszynski and Todd Feinberg the first book to reveal the biophysical basis of consciousness [to appear].
(xvi) Intradendritic computation by interaction of backpropagating action potentials [to appear].
(xvii) Mathematical modeling of intracellular signalling pathways involved in retinal direction selectivity [to appear].
(xviii) Solitons in a Hodgkin-Huxley system [to appear].
(xix) Electrolytic conduction of molecular action potentials as dissipative solitons [to appear].
(xx) Hodgkin-Huxley theory accords to no annihilation of colliding action potentials [to appear].