Meditation and Complexity: a Systematic Review

Abstract

Recent years have seen a growing interest in the use of measures inspired by complexity science for the study of consciousness. The work done in this field has shown remarkable results in discerning conscious from unconscious states, and in characterizing states of altered conscious experience following intake of psychedelic substances as involving enhanced complexity. However, the relationship between meditation and complexity is unclear, as empirical studies based on different theoretical frameworks point to meditation being associated with either enhancement or reduction of complexity. Here we provide a systematic review of the accumulating literature studying the complexity of neural activity in meditation, which disentangles different families of measures, short-term (state) from long-term (trait) effects, and meditation styles. Beyond families of measures used, our review uncovers a convergence toward identifying a higher complexity of neural activity during the meditative state when compared to waking rest or mind-wandering, and a decreased baseline complexity as a trait in experienced meditators compared to novices and controls. This review contributes to guide current debates and provides a framework for understanding the complexity of neural activity in meditation, while suggesting some practical guidelines for future research in the field.