“…However, the internal brain state is constantly fluctuating along a continuum, even in the absence of overt behavioral changes ( Harris and Thiele, 2011 ; Lee and Dan, 2012 ; McGinley et al, 2015b ; Poulet and Crochet, 2019 ): From a synchronized state characterized by strong, low-frequency delta oscillations to a desynchronized state where these are suppressed and high-frequency gamma oscillations become more pronounced. In turn, the brain state profoundly influences the operating mode of the brain by virtue of changes in, for example, spontaneous neuronal activity, the ability to execute motor commands, and responses to external sensory stimuli ( Cao and Händel, 2019 ; Destexhe et al, 1999 ; Livingstone and Hubel, 1981 ; Massimini et al, 2005 ; Polack et al, 2013 ).…”