Why do our eyes move when we dream? Scientists believe that the rapid eye movements (REM) that happen after we drift off into dream-world indicate that the person is dreaming. But, did you ever wonder as to what the individual eye movements actually stand for? The findings have been published in Nature Communications.
A hypothesis developed in the past suggested that each eye movement means that new visual information has been captured in the dream. A new study seems to have confirmed this theory; it is the first to have provided neuronal evidence for the link between REM sleep, dream images and accelerated brain activity.
The researchers obtained their data by sticking electrodes into the brains of 19 epileptic patients to monitor their brain activity. This procedure was done over 10 days. It is to be noted that the patients were to go through surgery to remove the seizure-causing regions from their brains.
“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 Yuval Nir, lead author of the study, in a press release.
“[P]rior 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.”
Furthermore, the researchers concluded that the brain acts in similar ways when seeing new images for real and in dreams.
“The electrical brain activity during rapid eye movements in sleep were highly similar to those occurring when people were presented with new images,” said Nir. “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,” added Itzhak Fried, a co-author of the research, “similar to the brain activity exhibited when one encounters visual images while awake.”