Sleep wake cycle
- 1. THE SLEEP – WAKE CYCLE By ARINDAM SAIN
- 2. Circadian Rhythms, Sleep–Wake Cycle The daily sleep–wake cycle and other circadian rhythms (diurnal rhythms) are controlled by endogenous rhythm generators The central biological clock (oscillator) that times these processes is located in the suprachiasmatic nucleus (SCN) of the hypothalamus The endogenous circadian rhythm occurs in cycles of roughly 24– 25 hours, but is unadulterated only when a person is completely isolated from the outside influences External zeitgebers (entraining signals) synchronize the biological clock to precise 24-hour cycles The main external zeitgeber for 24-hour synchronization of the sleep–wake cycle is bright light (photic entrainment)
- 3. Infants sleep longest (about 16 hours/day, 50% REM) 10-year-olds sleep an average 10 hours (20% REM) Young adults sleep 7–8 hours a day Adults over 50 sleep an average 6 hours (both 20 % REM) When a person is deprived of REM sleep, the duration of the next REM phase increases The first two to three sleep cycles (core sleep) are essential.
- 5. Consciousness: Selective attention, abstract thinking, the ability to verbalize experiences, the capacity to plan activities based on experience, self-awareness and the concept of values are some of the many characteristics of consciousness Attention: Sensory stimuli arriving in the sensory memory are evaluated and compared to the contents of the long-term memory within fractions of a second Sleep: is a state of physiologic recovery, regularly repeated at night. The day/night rhythm is associated with an altered state of consciousness.
- 6. Brain Wave States and Their Correlated Frequency and Physiology. •Ross et al., 2019
- 7. Hegerl et al., 2016
- 9. Thieme et al
- 10. • The functions of sleep are homeostasis (replenishment of energy reserves with high parasympathetic involvement) and consolidation (stabilization) of acquired procedural knowledge (spoken language, motor functions).
- 11. A model for the regulation of transitions to the awake state and sleep. Neuroscience, vol. 8, March 2007, 171–181.
- 12. THANK YOU