ABSTRACT
In recent decades, brain science has been enriched from both empirical
and computational approaches. Interesting emerging neural features include
power-law distribution, chaotic behavior, self-organized criticality, variance
approach, neuronal avalanches, difference-based and sparse coding, optimized
information transfer, maximized dynamic range for information processing, and
reproducibility of evoked spatio-temporal motifs in spontaneous activities, and
so on. These intriguing findings can be largely categorized into two classes:
complexity and regularity. This article would like to highlight that the
above-mentioned properties although look diverse and unrelated, but actually
may be rooted in a common foundation—excitatory and inhibitory balance (EIB)
and ongoing activities (OA). To be clear, description and observation of neural
features are phenomena or epiphenomena, while EIB-OA is the underlying
mechanism. The EIB is maintained in a dynamic manner and may possess regional
specificity, and importantly, EIB is organized along the boundary of phase transition
which has been called criticality, bifurcation or edge of chaos. OA is composed
of spontaneous organized activity, physiological noise, non-physiological noise
and the interacting effect between OA and evoked activities. Based on EIB-OA,
the brain may accommodate the property of chaos and regularity. We propose
“virtual brain space” to bridge brain dynamics and mental space, and “code
driving complexity hypothesis” to integrate regularity and complexity. The
functional implication of oscillation and energy consumption of the brain are
discussed.