Self-organized criticality as a framework for consciousness: A review study

Abstract

ObjectiveNo current model of consciousness is univocally accepted on either theoretical or empirical grounds, and the need for a solid unifying framework is evident. Special attention has been given to the premise that self-organized criticality (SOC) is a fundamental property of neural system. SOC provides a competitive model to describe the physical mechanisms underlying spontaneous brain activity, and thus, critical dynamics were proposed as general gauges of information processing representing a strong candidate for a surrogate measure of consciousness. As SOC could be a neurodynamical framework, which may be able to bring together existing theories and experimental evidence, the purpose of this work was to provide a comprehensive overview of progress of research on SOC in association with consciousness.MethodsA comprehensive search of publications on consciousness and SOC published between 1998 and 2021 was conducted. The Web of Science database was searched, and annual number of publications and citations, type of articles, and applied methods were determined.ResultsA total of 71 publications were identified. The annual number of citations steadily increased over the years. Original articles comprised 50.7% and reviews/theoretical articles 43.6%. Sixteen studies reported on human data and in seven studies data were recorded in animals. Computational models were utilized in n = 12 studies. EcoG data were assessed in n = 4 articles, fMRI in n = 4 studies, and EEG/MEG in n = 10 studies. Notably, different analytical tools were applied in the EEG/MEG studies to assess a surrogate measure of criticality such as the detrended fluctuation analysis, the pair correlation function, parameters from the neuronal avalanche analysis and the spectral exponent.ConclusionRecent studies pointed out agreements of critical dynamics with the current most influencing theories in the field of consciousness research, the global workspace theory and the integrated information theory. Thus, the framework of SOC as a neurodynamical parameter for consciousness seems promising. However, identified experimental work was small in numbers, and a heterogeneity of applied analytical tools as a surrogate measure of criticality was observable, which limits the generalizability of findings.

Spontaneous neuronal avalanches as a correlate of access consciousness

“…SOC offers an attractive theoretical framework for the brain, since it predicts the empirical evidences of optimal information processing (Shew et al, 2011;Shew and Plenz, 2013), dynamical range (Kinouchi and Copelli, 2006;Larremore et al, 2011), and maximization of metastability (Tognoli and Kelso, 2014). It was previously suggested that SOC could serve as a framework for Consciousness as well (Werner, 2009;Carhart-Harris et al, 2014;Tagliazucchi, 2017;Walter and Hinterberger, 2022). In fact, criticality was linked to IIT as a necessary condition for integration of information (Kim and Lee, 2019;Popiel et al, 2020), and it is compatible with predictions from the GNW hypothesis (Tagliazucchi, 2017), among other frameworks.…”

Sensory-Processing Sensitivity Is Associated with Increased Neural Entropy

“…The analysis was based on the hypothesis that there might be a correlation between the level of SPS and criticality and neural complexity. While the notion that neural dynamics are governed by the phenomenon of self-organized criticality has received criticism [ 20 ], a substantial body of research emphasized the potential of critical dynamics as general indicators of healthy functioning of information processing and a surrogate measure of consciousness [ 33 , 34 ]. Such findings inspired the research question and the investigation whether the modulation of critical dynamics might be an underlying mechanisms of SPS.…”

Criticality of resting-state EEG predicts perturbational complexity and level of consciousness during anesthesia

“…PCF was estimated using a custom Python function (available in edgeofpy). Prior to calculation, the signal was downsampled to 250 Hz and bandpass-filtered in the alpha frequency range (8)(9)(10)(11)(12)(13). The PCF was estimated on every non-overlapping 10-s epoch individually and subsequently averaged over time.…”

“…At this fine balance point, systems display optimal computational capacity, maximally complex patterns, and divergent sensitivity to external perturbation. In virtue of these features, criticality is increasingly explored as a requirement for healthy brain function (2)(3)(4) and the emergence of consciousness (5)(6)(7)(8).…”