Get Adobe Flash player

Social groups

Dolphin’s dream

The dream of dolphin differs from the dream of human being. If the human being’s process of sleeping characterized by the partial or full absence of consciousness, inactivity of the group of voluntary muscles (the kind of muscles we usually control) and by the inactivity of hearing and smelling, dolphin’s dream seems to be different.

In the process of sleeping dolphin has only one inactive cerebral hemisphere, the second one is always active. The activity of hemispheres during the sleeping process takes place alternately. The left eye of the dolphin will be closed while the right hemisphere is dreaming, the left eye will be closed in case of left hemisphere’s inactivity. Sometimes dolphins keep their bodies on the surface of water during the sleep, sometimes they can slowly swim.

The dolphin’s active brain part is always watching the course of the dolphin, the water condition and controls the functions of breathing.

Scientists observed the dolphins that were able to sleep on the bottom of the pool (coming out from the water to take a breath from time to time).

There are three main reasons why dolphins have this kind of sleeping:

-Dolphins would drown without one active brain part, because they always control the process of breathing

-This kind of sleep gives them an opportunity to check the probable danger

-It helps them to maintain the muscle activity for urgent processes (for instance, for keeping the body temperature in a cold water)