Dreams Reset Through 'Snapshopts' In Rare Study On REM Data
Most are familiar with the acronym REM (rapid eye movement) or the period in which one experiences vivid dreams. Yet did you know it's not so long ago that scientists first discovered that REM sleep cycles were associated with dreaming?
New findings published in Nature Communications look back to the rare neuronal data on the first scientific evidence of a link between rapid eye movement, accelerated brain activity and dream images. Studies show that specific brain regions surge with activity, just as if an individual was introduced to a new image, when our eyes are moving during REM sleep--thus, suggesting that eye movements during REM sleep are responsible for resetting our dream "snapshots."
The original study examined by researchers was conducted on 19 epileptic patients at the UCLA Medical Center, who required invasive monitoring of brain activity before potential surgical excision of seizure-causing areas of the brain. Each patient received electrodes that were implanted inside the patients' brains to study any activity that went on over the span of 10 days; this helped provide the rare data on connections between eye movements, dream imagery and brain activity.
"We focused on the electrical activities of individual neurons in the medial temporal lobe, a set of brain regions that serve as a bridge between visual recognition and memories," said lead study author Dr. Yuval Nir of Tel Aviv University's Sackler Faculty of Medicine, in a news release. "Prof. Fried's prior research had shown that neurons in these regions become active shortly after we view pictures of famous people and places, such as Jennifer Aniston or the Eiffel Tower -- even when we close our eyes and imagine these concepts."
In addition to monitoring the patients' brain activity via intracranial electrodes, the researchers also recorded scalp EEG, muscle tone, and eye movements to identify periods of REM sleep and detect the precise moment of each rapid eye movement.
"The electrical brain activity during rapid eye movements in sleep were highly similar to those occurring when people were presented with new images," Dr. Nir added. "Many neurons -- including those in the hippocampus -- showed a sudden burst of activity shortly after eye movements in sleep, typically observed when these cells are 'busy' processing new images."
"The research findings suggest that rapid eye movements represent the moment the brain encounters a new image in a dream, similar to the brain activity exhibited when one encounters visual images while awake," concluded researcher TAU's Prof. Itzhak Fried.
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