Non-rapid eye movement sleep activation occurs during NREM that is comparable to the type that occurs during REM. It is this sub-cortical activation that results in dreaming during the NREM stage during the morning hours. During non-REM sleep, the tonic drive to most respiratory muscles of the upper airway is inhibited. This has two consequences: However, because the diaphragm is largely driven by the autonomous system, it is relatively spared of non-REM inhibition. As such, the suction pressures it generates stay the same. This narrows the upper airway during sleep, increasing resistance and making airflow through the upper airway turbulent and noisy. For example,
Activation-synthesis hypothesis the stages of sleep that show greatly decreased brain activity. There are four different stages of NREM sleep. The brain shows dulled or limited senses of perception, though the thought process has been shown to be logical and perseverative. Episodic movements of the body occur during these stages, though they are involuntary movements. REM sleep is an evolutionarily recent behavior of humans. REM stands for rapid eye movement. It is the deepest sleep a mammal can go into. It is regulated by the pontine brainstem. Infants spend most of their time in REM sleep, and rather than enter stage 1