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(Color online) Average degree distribution Pav(k) for different sleep phases (cycle I). Point legend as in Fig. 1: Presleep wakefulness, shallow sleep, slow-wave sleep, and REM sleep are, respectively, indicated with open red squares, filled green circles, blue filled up triangles, and purple open down triangles. Green dashed and red continuous lines are eye guides for exponential exp(−k/3) and inverse-power law ∝ 1/k1.1, respectively.
