Furthermore, rumination and poor coping resources may play a significant role in sleep misperception. Spectral analysis
According to a May 2014 article published in New Scientist, spectral analysis may help clinicians find objective evidence for sleep state misperception:

[...] it uncovered [...] subtle differences in the EEGs of sleeping insomniacs: alpha waves – signatures of wakefulness that are supposed to show up only in early sleep – were intruding into deep sleep. [...] [psychologist and sleep researcher Michael] Perlis. But Andrew Krystal of Duke University in Durham, North Carolina, used spectral analysis to quantify just how much they were intruding. Krystals non-sleepers not only had a greater proportion of these alpha disturbances, but the alpha waves were bigger and the delta waves were correspondingly smaller. That wasnt all. When Perlis and other researchers applied spectral analysis algorithms to the EEGs of their sleeping insomniacs, they found different patterns, fast waves known as beta and gamma (Sleep, vol 24, p 110). Normally, these are indicators of consciousness, alertness and even anxiety [...] Like alpha waves, Perlis calls these beta and gamma waves "intrusions" into normal sleep: "Its as if somebody is playing with the switch – boop, boop – flipping at a mad rate between wake and sleep". Distinction from insomnia
What is considered objective insomnia, unlike SSM, can easily be confirmed empirically through clinical testing, such as by polysomnogram. Those who experience SSM may believe that they have not slept for extended periods of time, when they in fact do sleep but without perceiving it.
Endometrial stromal tumours are a type of mesenchymal tumor of the main body of the uterus. Types include endometrial stromal nodule, the distinct low and high-grade endometrial stromal sarcomas, and undifferentiated uterine sarcoma. == References ==