Breakdown of long-range temporal dependence in default mode and attention networks during deep sleep
Proceedings of the National Academy of Sciences September 3, 2013 Enzo Tagliazucchi, Frederic von Wegner, Astrid Morzelewski et al. 278 citations
A conscious brain integrates information across segregated functional modules and also maintains long-term memory in its neural activity. This study examined temporal memory in blood oxygen level-dependent signals across the human nonrapid eye movement sleep cycle. Temporal dependence gradually decreased from wakefulness to deep nonrapid eye movement sleep, particularly in default mode and attention networks. Although spatial organization of spontaneous fluctuations remained nontrivial even during deep sleep, temporal complexity decreased in specific brain regions. These findings suggest that long-range temporal dependence may be a characteristic of the spontaneous conscious mentation that occurs during wakeful rest.