SIREN CALL OF METAPHOR: SUBVERTING THE PROPER TASK OF NEUROSCIENCE

Letting the brain speak for itself

Metaphors of Computation and Information tended to detract attention from the intrinsic modes of neural system functions, uncontaminated by the observer's role in collection, and interpretation of experimental data. Recognizing the self-referential mode of function, and the propensity for self-organization to critical states requires a fundamentally new orientation, based on Complex System Dynamics as non-ergodic, non-stationary processes with inverse-power-law statistical distributions. Accordingly, local cooperative processes, intrinsic to neural structures, and of fractal nature, call for applying Fractional Calculus and models of Random Walks with long-term memory in Theoretical Neuroscience studies.

Viewing brain processes as Critical State Transitions across levels of organization: Neural events in Cognition and Consciousness, and general principles

In this theoretical and speculative essay, I propose that insights into certain aspects of neural system functions can be gained from viewing brain function in terms of the branch of Statistical Mechanics currently referred to as "Modern Critical Theory" [Stanley, H.E., 1987. Introduction to Phase Transitions and Critical Phenomena. Oxford University Press; Marro, J., Dickman, R., 1999. Nonequilibrium Phase Transitions in Lattice Models. Cambridge University Press, Cambridge, UK]. The application of this framework is here explored in two stages: in the first place, its principles are applied to state transitions in global brain dynamics, with benchmarks of Cognitive Neuroscience providing the relevant empirical reference points. The second stage generalizes to suggest in more detail how the same principles could also apply to the relation between other levels of the structural-functional hierarchy of the nervous system and between neural assemblies. In this view, state transitions resulting from the processing at one level are the input to the next, in the image of a 'bucket brigade', with the content of each bucket being passed on along the chain, after having undergone a state transition. The unique features of a process of this kind will be discussed and illustrated.

Imaging and imagining: current positions on the epistemic priority of theoretical concepts and data in psychiatric neuroimaging

PURPOSE OF REVIEW

To give an overview of recent developments in neuroimaging in psychiatry and on the current discussion about the relationship between theoretical concepts and data from neuroimaging studies.

RECENT FINDINGS

In psychiatric neuroimaging, broad concepts such as the self, well being, insight, empathy and volition form an integral part of the questions to be answered and cannot be avoided. Although, currently, the intradisciplinary discussion in neuroscience is mainly focused at the methodological and neurobiological level, psychological and philosophical theories are also needed for the interpretation of results. This raises questions regarding the epistemic priority of neuroimaging data and theories.

SUMMARY

In the current paper, we present the hypothesis that there is an interdependence of neuroimaging data and theoretical concepts. An approach to 'correlational neuroscience' with an awareness of this issue may help in avoiding misunderstandings and oversimplifications as well as building an interdisciplinary theoretical framework that is able to integrate findings from life sciences, mind sciences and humanities.

Where and how could intentional programs be generated in the brain?

Based on glial-neuronal interaction a formalism (negative language) for the generation of intentional programs is proposed. An intentional program generates a specific multirelational structure in an inner or outer appropriate environment according to the principle of feasibility. After description of the glial spatio-temporal boundary-setting function in its interaction with the neuronal system, it is hypothesized that intentional programs may be generated in glial networks (syncytia) in line with the formalism of negative language. Gap junctions are interpreted as multirelational negation operators, generating cycles in a permutation system. These cycles could represent intentional programs that can either be realized or not in neuronal networks embodying a permutation system. The feasibility of these intentional programs is essentially dependent on appropriate environmental information. Since the realization of intentional programs in neuronal networks allows high degrees of freedom, the problem of free will is tackled, as well. Free will is defined as the subjective freedom to choose between the inner determination of intentional programs and the overdetermination of their feasibility in an appropriate environment. Finally, the possible implementation of the proposed brain model in robot brains is briefly discussed.

Perspectives on the Neuroscience of Cognition and Consciousness

The origin and current use of the concepts of computation, representation and information in Neuroscience are examined and conceptual flaws are identified which vitiate their usefulness for addressing the problem of the neural basis of Cognition and Consciousness. In contrast, a convergence of views is presented to support the characterization of the Nervous System as a complex dynamical system operating in a metastable regime, and capable of evolving to configurations and transitions in phase space with potential relevance for Cognition and Consciousness.

Metastability, criticality and phase transitions in brain and its models

This survey of experimental findings and theoretical insights of the past 25 years places the brain firmly into the conceptual framework of nonlinear dynamics, operating at the brink of criticality, which is achieved and maintained by self-organization. It is here the basis for proposing that the application of the twin concepts of scaling and universality of the theory of non-equilibrium phase transitions can serve as an informative approach for elucidating the nature of underlying neural-mechanisms, with emphasis on the dynamics of recursively reentrant activity flow in intracortical and cortico-subcortical neuronal loops.