Consciousness, Sleep and Hypnosis, Meditation, and Psychoactive Drugs
Mohamed Ahmed Abd El-Hay in Understanding Psychology for Medicine and Nursing, 2019
This phase of sleep is accompanied by considerable physiological arousal. Eyes move back and forth behind closed eyelids (the rapid eye movements), the heart rate, blood pressure, and respirations can fluctuate up and down. This phase is also known as paradoxical sleep, because while the brain and other body systems become more active, the muscles become more relaxed, which prevents the dreaming sleeper from acting out his or her dreams. Sexual arousal may occur in both sexes in this stage unrelated to dreams. Dreams usually occur during REM sleep. Stoppage of drugs that suppress REM sleep after prolonged intake lead to rebound symptoms, including vivid dreaming or even visual hallucinations. On average, we enter the REM stage approximately 90 minutes after falling asleep. The first cycle of REM sleep might last only 5–15 minutes, but each cycle becomes longer as sleep progress.
The biological and evolutionary foundations of sleep and dreams
Frederick L. Coolidge, Ernest Hartmann in Dream Interpretation as a Psychotherapeutic Technique, 2018
It is interesting to think that about 50 years ago the scientific study of sleep and dreams received a tremendous boost. Despite written records of dreams that date back over 4500 years, it was not until 1953 that University of Chicago sleep researchers Kleitman and his doctoral student Aserinsky discovered that their human sleep subjects not only slowly moved their eyes while falling asleep but also began to move their eyes rapidly during sleep. Aserinsky first noticed these eyes movements in sleeping infants. Later, in their studies with adults, they found these eye movements (called REM for rapid eye movements) coincided with the most vivid dreams throughout the entire sleep period. Aserinsky and Kleitman used an electroencephalograph (EEG) in order to measure their subjects’ sleep. The EEG is a sophisticated machine used to amplify the tiny amounts of electrical activity produced primarily by the surface of the brain, the cortex. Now, sleep researchers regularly attach electrodes not only about their subjects’ heads but also they place two electrodes about the outer area of each eye socket in order to measure the presence of REM sleep. Quickly after Aserinsky and Kleitman’s important discovery, the hypothesis became popular that a human’s sleep could be divided into five sleep stages, four of them containing non-REM sleep and one containing REM sleep (e.g., Dement, 1972). Animal researchers also looked for the presence of REM sleep, and they found that almost all mammals have REM sleep, and nearly all reptiles, fishes, and birds do not.
Audio Visual Entrainment and Acupressure Therapy for Insomnia
Anne George, Oluwatobi Samuel Oluwafemi, Blessy Joseph, Sabu Thomas, Sebastian Mathew, V. Raji in Holistic Healthcare, 2017
During stage 1, which is light sleep, one drifts in and out of sleep and can be awakened easily. The eyes move very slowly and muscle activity slows. People awakened from stage 1 sleep often remember fragmented visual images. Many also experience sudden muscle contractions called hypnic myoclonia, often preceded by a sensation of starting to fall. When entering stage 2 sleep, the eye movements stop and brain waves become slower, with occasional bursts of rapid waves called sleep spindles. In stage 3, extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. By stage 4, the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called deep sleep. There is no eye movement or muscle activity. When the brain switches into REM sleep, the breathing becomes more rapid, irregular, and shallow, the eyes jerk rapidly in various directions, and the limb muscles become temporarily paralyzed. Heart rate and blood pressure are shown to increase. This is the stage of the sleep cycle in which dreams occur.
Sleep disruption induces activation of inflammation and heightens risk for infectious disease: Role of impairments in thermoregulation and elevated ambient temperature
Published in Temperature, 2023
Michael R. Irwin
Over the course of the sleep period, humans show a transition from wakefulness to entry into NREM sleep, followed by transition to REM sleep. (Figure 1) At the end of a REM period, a brief arousal or awakening may occur, followed by entry into another NREM sleep period. This cycle from NREM sleep to REM sleep, with each cycle lasting about 80 to 110 minutes, typically repeats four to six times over the course of the night. Additionally, during the early part of the night, sleep architecture reveals that NREM phase is predominated by N3 or SWS, and episodes of REM episodes are short. In contrast, during the latter part of the night, REM episodes are longer and more frequent. Whereas scoring dimensions might suggest that sleep is a quantal behavioral state [37], brain activity shows a continuous progression across the NREM domain from wakefulness to deep sleep. Indeed, spectral analytic methods reveal continuous shifting of mixed EEG frequencies to predominately lower EEG frequencies in the transition from awake to NREM sleep and N3 sleep [39]. Slow-wave activity (SWA), a measure of the density and amplitude of slow waves, is thought to capture the depth of sleep and is markedly increased after prolonged period of wakefulness [40], with potential effects on recovery of immune response following sleep loss [41].
EEG coherence and power spectra during REM sleep related to melatonin intake in mild-to-moderate Alzheimer’s disease: a pilot study
Published in International Journal of Neuroscience, 2023
Manuel Alejandro Cruz-Aguilar, Ignacio Ramírez-Salado, Marisela Hernández-González, Miguel Angel Guevara, Ana Paula Rivera-García
There is a growing body of research on humans and animals that provides evidence for a prominent role of REM sleep in memory consolidation [17, 43]. Thus, it is important to test pharmacological alternatives that may improve the clinical conditions of REM sleep in AD patients. For this reason, the aim of the present study was to determine the effect of melatonin on EEG activity and the degree of EEG synchronization between different cortical areas during REM sleep in AD patients who received melatonin. Considering that melatonin reduces brain electrical activity by modulating GABAA receptors [31–35], that GABArgic activity is required for REM sleep generation [23–27], and that melatonin intake in AD patients reduces REM sleep latency [37], we hypothesized that the facilitator effect of melatonin on REM sleep onset will be associated with a lower percentage of fast frequencies (in β and γ) and a decrease in the degree of EEG synchronization (coherence) between cortices in these same fast frequencies. To test these hypotheses, we evaluated the effects of melatonin on REM sleep latency, EEG spectral power, and EEG coherences during the first nocturnal episode of REM sleep in a group of mild-to-moderate AD patients previously treated with melatonin [41, 42].
D-ribose-L-cysteine modulates paradoxical sleep deprivation-induced neurological impairments: anxiolytic and antioxidative study in rat model
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Taiwo Abayomi, Olorunfemi Tokunbo, Oluwatobiloba Oroyemi, Olawale Abayomi, Opeyemi Osuntokun, Benedict Falana, Temidayo Adeniyi
Sleep is a ubiquitous phenomenon and most species, including humans spend a significant time asleep. It is widely acknowledged that sleep is crucial for proper brain function. There are five phases of sleep: the wake phase, non-rapid eye movement (NREM) phase, which has 3 stages (N1 to N3), and the rapid eye movement (REM) phase. Wakefulness is characterized by more than 50% alpha waves and opening of the eyes. The N1 stage of the NREM phase is the most superficial stage of sleep characterized by skeletal muscle tone and regular breathing rate. The N2 stage, where the majority of sleep is spent, typifies a deeper stage of sleep characterized by lowered body temperature and heart rate. As deeper sleep develops, there is a transition to the N3 stage of NREM. This is the deepest stage of sleep when the body repairs worn-out tissues, builds bones and strengthens the immune system. REM sleep usually begins about 90 minutes after an individual falls asleep. Apart from the eye and diaphragmatic breathing muscles which remain active, all other skeletal muscles are inactive. The REM stage of sleep is characterized by dreaming and erratic breathing rate [1].
Related Knowledge Centers
- Brainstem
- Eye
- Monoamine Neurotransmitter
- Neural Oscillation
- Sleep
- Muscle Tone
- Neurotransmitter
- Acetylcholine
- Dream
- NON-Rapid Eye Movement Sleep