Why rapid eye movement

So Nir, Dr. Itzhak Fried, a cognitive neurophysiologist at UCLA, and their colleagues asked 19 people who were having brain implants for epilepsy if they would also be willing to have some of their brain activity recorded while they slept. The brain recordings revealed that every time the dreamers moved their eyes, neurons in the medial temporal lobe of the brain showed a burst in activity, the researchers reported today Aug.

In past studies, Fried had found that the medial temporal lobe lit up when people looked at images of famous people and places, such as the Golden Gate Bridge or Jennifer Aniston; simultaneously, they also made eye movements similar to those found during REM sleep. In Fried and his colleagues published a paper in the journal Nature showing that neurons in this brain region were under voluntary, conscious control when people were awake.

The new study finally confirms the long-held hypothesis that eye movements during REM sleep correspond to people visualizing imagery in their dreams, said Dr. Allan Hobson, a psychiatrist and sleep researcher at Harvard Medical School in Massachusetts, who was not involved in the current study. Many other parts of the brain were also active during REM sleep, and the team still isn't sure how those brain regions are involved in dreaming, Nir said.

Theoretically, researchers could one day read someone's dream activity using brain-firing data, determining whether the person was visualizing, say, an adorable kitten versus a scary monster. To do that, researchers would have to record someone's brain cell-firing signals during sleep, and then wake the person up to ask about the dream that individual was having. They would also need to collect data on the brain's electrical firing signals when the person viewed those same images during wakefulness.

Stages 3 and 4 non-REM sleep — a state of deep and restorative sleep known as slow-wave sleep, or delta sleep. The muscles relax, the supply of blood to the muscles increases, and the body repairs and grows tissue. Hormones are released and energy stores are replenished. As people age, they tend to get less NREM sleep. Those under 30 usually experience 2 hours of restorative sleep nightly while older adults may get just 30 minutes.

REM sleep is believed to benefit learning, memory, and mood. It is also thought to contribute to brain development in infants. A lack of REM sleep may have adverse implications for physical and mental health. Research suggests that when people are unable to enter REM sleep, they have difficulty remembering what they were taught before falling asleep.

One study on rats has shown that just 4 days of REM sleep deprivation affects cell proliferation in the part of the brain that contributes to long-term memory. REM sleep may be especially important for brain development in infants. Some research indicates that this sleep stage is responsible for the neural stimulation necessary to develop mature neural connections. These findings may help explain why infants require higher levels of REM sleep each night, with the number of minutes of REM sleep falling as people age.

Reduced coping skills — research indicates that animals who are deprived of REM sleep show abnormalities in coping mechanisms and defensive responses in threatening situations. Migraines — not getting enough REM sleep has been linked to migraines. Overweight — a University of Pittsburgh study found that short sleep times and reduced REM sleep was associated with excess weight in children and adolescents.

While drinking alcohol may help some people fall asleep quicker, research suggests that it reduces REM sleep. A review of 27 studies on alcohol and sleep found that total nightly REM sleep was decreased at moderate and high intakes of alcohol, although no clear trend was seen at low levels of alcohol intake.

Alcohol affects sleep in other ways, too. This causes the person to act out vivid dreams. For example, they may kick, yell, or flail their arms about. Researchers have now discovered that the Neuroscientists show that melanin-concentrating hormone neurons within the That's according to a meta-analysis. Children with migraines were also found to The research could potentially inform efforts to The research also demonstrated that this increase is associated These neurons commonly expressed the gene that encodes the neuropeptide neurotensin.

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