Table 1 Glossary of technical terms.

Brain dynamic

It explores the temporal evolution of brain activity, including the transmission of information between brain regions and the variation of their statistical dependencies, which might underpin to complex behaviour

Zalesky et al. (2014)⁴

Criticality

Critical systems exhibit scale-free fluctuations, and produce a dynamics which is “between order and disorder”. Critical systems can typically be explored by robust statistical analysis and modelling. A critical system operates in a highly variable, adaptive, and flexible dynamic regime

Cocchi et al. (2017)⁷

Brain flexibility

It refers to the brain's ability to explore a large number of its possible dynamical states

Pinto et al. (2022)⁸

Neuronal avalanches

A cascade of neural events (e.g. action potentials) that starts from a single event and propagates throughout the network, typically across spatial and temporal scales These cascades have been described by a critical branching process

Beggs et al. (2003)⁹

Branching ratio (σ)

The ratio between the number of activations in consecutive time steps. When σ = 1, the system is operating at criticality

Haldeman et al. (2005)¹⁰

Functional Repertoire

The number of unique avalanche configurations (pattern) that occurred during the recording. The size of the functional repertoire represents a measure of flexibility of brain activity. For a graphical representation see Fig. 2

Ribeiro et al. (2016)¹¹

Shared functional repertoire

Avalanche pattern that occurs in more than one phase of the menstrual cycle. For a graphical representation see Fig. 2

Sorrentino et al. (2021)¹²

Phase specific functional repertoire

Avalanche pattern specific to only one phase of the menstrual cycle. For a graphical representation see Fig. 2

Sorrentino et al. (2021)¹²

Switches

Occurs when the value of a time series crosses the threshold in either direction (an active region becomes inactive, and vice versa)

Sorrentino et al. (2021)¹²