Can We Awake And Sleep At The Same Time?

Natchya Tiwari

 

All vertebrate brains consist of two Hemispheres: The Right and The Left. Brain activity is usually similar across both during sleep. But, during asymmetrical sleep, one brain hemisphere can be in deep sleep while the other is in lighter sleep. In an extreme version it is called “unihemispheric sleep,” i.e., one hemisphere may appear completely awake while the other is in deep sleep.

 

 

Let’s look at the bottle nose dolphins. Their breathing is consciously controlled and they must surface for air every few minutes or they’ll drown. When they have a newborn calf they have to keep it safe. So dolphins sleep unihemispherically with just one hemisphere at a time this allows them to continue swimming and breathing while snoozing.

 

 

Other marine mammals also need asymmetrical sleep. With their nostrils above the surface, closing their upward-facing eye, and keeping their downward-facing eye open. This may help them stay alert to threats from the depths. Same as Mallard ducks, they spend more time in unisleeping with their eyes open and other birds which travel a flight of up to 10 days, frigate birds either sleep with one or both hemispheres at a time.

 

This suggests that, like other animals, humans use asymmetrical sleep for vigilance, specifically in unfamiliar environments. While you’re in a sleep, your brain is still keeping you alert!

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