Breakdown of Cortical Effective Connectivity During Sleep

@article{Massimini2005BreakdownOC,
  title={Breakdown of Cortical Effective Connectivity During Sleep},
  author={Marcello Massimini and Fabio Ferrarelli and Reto Huber and Steve K. Esser and Harpreet Singh and Giulio Tononi},
  journal={Science},
  year={2005},
  volume={309},
  pages={2228 - 2232}
}
When we fall asleep, consciousness fades yet the brain remains active. Why is this so? To investigate whether changes in cortical information transmission play a role, we used transcranial magnetic stimulation together with high-density electroencephalography and asked how the activation of one cortical area (the premotor area) is transmitted to the rest of the brain. During quiet wakefulness, an initial response (∼15 milliseconds) at the stimulation site was followed by a sequence of waves… 
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