Computation Emerges from Adaptive Synchronization of Networking Neurons

The activity of networking neurons is largely characterized by the alternation of synchronous and asynchronous spiking sequences. One of the most relevant challenges that scientists are facing today is, then, relating that evidence with the fundamental mechanisms through which the brain computes and processes information, as well as with the arousal (or progress) of a number of neurological illnesses. In other words, the problem is how to associate an organized dynamics of interacting neural assemblies to a computational task. Here we show that computation can be seen as a feature emerging from the collective dynamics of an ensemble of networking neurons, which interact by means of adaptive dynamical connections. Namely, by associating logical states to synchronous neuron's dynamics, we show how the usual Boolean logics can be fully recovered, and a universal Turing machine can be constructed. Furthermore, we show that, besides the static binary gates, a wider class of logical operations can be efficiently constructed as the fundamental computational elements interact within an adaptive network, each operation being represented by a specific motif. Our approach qualitatively differs from the past attempts to encode information and compute with complex systems, where computation was instead the consequence of the application of control loops enforcing a desired state into the specific system's dynamics. Being the result of an emergent process, the computation mechanism here described is not limited to a binary Boolean logic, but it can involve a much larger number of states. As such, our results can enlighten new concepts for the understanding of the real computing processes taking place in the brain.

[1]  Sudeshna Sinha,et al.  Using synchronization to obtain dynamic logic gates. , 2007, Physical review. E, Statistical, nonlinear, and soft matter physics.

[2]  Sudeshna Sinha,et al.  Chaogates: morphing logic gates that exploit dynamical patterns. , 2010, Chaos.

[3]  L. M. Ward,et al.  Stochastic resonance and sensory information processing: a tutorial and review of application , 2004, Clinical Neurophysiology.

[4]  S. Shen-Orr,et al.  Network motifs: simple building blocks of complex networks. , 2002, Science.

[5]  Albert,et al.  Emergence of scaling in random networks , 1999, Science.

[6]  Huxley Af,et al.  A quantitative description of membrane current and its application to conduction and excitation in nerve. 1952. , 1990 .

[7]  A. S. Pikovskii Synchronization and stochastization of array of self-excited oscillators by external noise , 1984 .

[8]  Grebogi,et al.  Communicating with chaos. , 1993, Physical review letters.

[9]  E. Gordon,et al.  Synchronous Gamma activity: a review and contribution to an integrative neuroscience model of schizophrenia , 2003, Brain Research Reviews.

[10]  S. Shen-Orr,et al.  Networks Network Motifs : Simple Building Blocks of Complex , 2002 .

[11]  W. Singer,et al.  Oscillatory Neuronal Synchronization in Primary Visual Cortex as a Correlate of Stimulus Selection , 2002, The Journal of Neuroscience.

[12]  A. Turing On Computable Numbers, with an Application to the Entscheidungsproblem. , 1937 .

[13]  J. Martinerie,et al.  The brainweb: Phase synchronization and large-scale integration , 2001, Nature Reviews Neuroscience.

[14]  Jurgen Kurths,et al.  Synchronization in complex networks , 2008, 0805.2976.

[15]  Alonzo Church,et al.  A. M. Turing. On computable numbers, with an application to the Entscheidungs problcm. Proceedings of the London Mathematical Society , 2 s. vol. 42 (1936–1937), pp. 230–265. , 1937, Journal of Symbolic Logic.

[16]  A. Hodgkin,et al.  A quantitative description of membrane current and its application to conduction and excitation in nerve , 1952, The Journal of physiology.

[17]  E. John,et al.  Decreased EEG synchronization in Alzheimer’s disease and mild cognitive impairment , 2005, Neurobiology of Aging.

[18]  Albert-László Barabási,et al.  Statistical mechanics of complex networks , 2001, ArXiv.

[19]  Thomas C. Bartee Computer architecture and logic design , 1991, McGraw-Hill international editions: computer science series.

[20]  William L. Ditto,et al.  DYNAMICS BASED COMPUTATION , 1998 .

[21]  Michael Breakspear,et al.  A Novel Method for the Topographic Analysis of Neural Activity Reveals Formation and Dissolution of ‘Dynamic Cell Assemblies’ , 2004, Journal of Computational Neuroscience.

[22]  William Wernick Complete sets of logical functions , 1942 .

[23]  F. Varela,et al.  Perception's shadow: long-distance synchronization of human brain activity , 1999, Nature.