Trait-like stability of REM density. A: REM density during REM sleep and NREM sleep per animal per night (three different nights are separately plotted). B: REM sleep and NREM sleep percentage per animal per night. C: Trait-like stability of REM density and sleep stage proportion, quantified as ICC from a linear mixed model analysis (see statistical analysis).
Fulda et al. BMC Neuroscience 2011 12:110 doi:10.1186/1471-2202-12-110