Multiscale criticality measures as general-purpose gauges of proper brain function.

The brain is understood as an information processing system, and its activity is organized into hierarchical spatiotemporal loops. Successful processing depends on matching the multiscale delay structure of neural networks. Reduced information processing capacity appears as deviations from this multiscale character, captured by multiscale criticality measures (MsCr). Applying MsCr to MEG and EEG data, the authors found that MsCr measures systematically varied with information processing capacity across four compromised states: disorders of consciousness, mild cognitive impairment, schizophrenia, and pre-ictal activity. The authors propose that MsCr measures might serve as general gauges of information processing capacity and normative measures of brain health.

Study at a glance

Abstract

The brain is universally regarded as a system for processing information. If so, any behavioral or cognitive dysfunction should lend itself to depiction in terms of information processing deficiencies. Information is characterized by recursive, hierarchical complexity. The brain accommodates this complexity by a hierarchy of large/slow and small/fast spatiotemporal loops of activity. Thus, successful information processing hinges upon tightly regulating the spatiotemporal makeup of activity, to optimally match the underlying multiscale delay structure of such hierarchical networks. Reduced capacity for information processing will then be expressed as deviance from this requisite multiscale character of spatiotemporal activity. This deviance is captured by a general family of multiscale criticality measures (MsCr). MsCr measures reflect the behavior of conventional criticality measures (such as the branching parameter) across temporal scale. We applied MsCr to MEG and EEG data in several telling degraded information processing scenarios. Consistently with our previous modeling work, MsCr measures systematically varied with information processing capacity: MsCr fingerprints showed deviance in the four states of compromised information processing examined in this study, disorders of consciousness, mild cognitive impairment, schizophrenia and even during pre-ictal activity. MsCr measures might thus be able to serve as general gauges of information processing capacity and, therefore, as normative measures of brain health.