Activation of task activity during sleep is related to muscle activity. Activation of PC1 during sleep is related to muscle activity. Significant cross-correlations between PC1 activation and EMG activity occurred in Rest 1 REM (ANOVA F1,4 = 12.1, p < 0.05) and Rest 2 SWS (ANOVA F1,4 = 7.8, p < 0.05; green is time-shuffled EMG, shaded areas are s.e.m. of n = 5). (Online version in colour.)