Towards a statistical mechanics of brain coordination dynamics: maximization of number of connections is associated with conscious awareness

PEREZ VELAZQUEZ, J.L.; MATEOS DIEGO; GUEVARA ERRA, R.

Conferencia; ESI Systems Neuroscience Conference; 2017

Great attention in current neuroscience research concentrates on the understanding of how the coordinated activity of functionally connected brain cell ensembles determines, or is associated with, cognition and pathological states. The common notions used in these studies are centred on the determination of magnitudes of indices of correlated activity such as synchrony and the derivation of connectivity and other similar measures. In order to make sense of all these extremely abundant data that are being generated, the search for organising principles of brain function is today more crucial than ever. We sought to identify global features of brain organization that are optimal for sensory processing and that may guide the emergence of conscious awareness. Our results provide a (very simple) answer to the question of what the magnitudes of synchrony indices represent in terms of the structure of brain activity. We have followed the classic approach in physics when it comes to understanding collective behaviours of systems composed of a myriad of units: the assessment of the number of possible configurations, or microstates, that the system can adopt.  In our study we focus on the collective level of description and assume that coordinated patterns of brain activity evolve due to interactions at the mesoscopic level. Thus we use several types of brain recordings (magnetoencephalography, scalp and intracerebral electroencephalography) in conscious and unconscious states ―sleep stages and seizures― in order to evaluate the number of ?connections? between brain areas and the associated entropy and complexity. We present evidence that conscious states result from higher entropy and complexity in the number of configurations of pairwise connections. The number of pairwise channel combinations is near the maximum of all possible configurations when the individual is processing sensory inputs in a normal manner (e.g. with open eyes). Our interpretation is that a greater number of configurations of interactions allow the brain to optimally process sensory information, fostering the necessary variability in brain activity needed to integrate and segregate sensorimotor patterns associated with conscious awareness. Therefore, the information content is larger in the network associated to conscious states, suggesting that consciousness could be the result of an optimization of information processing. These findings encapsulate three main theories of cognition and help to guide in a more formal sense inquiry into how consciousness arises from the organization of matter