Do animals dream?
While scientists and common people alike have always been fascinated by the idea of dreaming and have been trying to discover the secret behind dreams, have we ever wondered if our pet cat dreams as we do?
Dreams have always been considered a distinguishing factor between humans and animals.
However, by conducting many rigorous experiments, researchers have proved that animals also dream during sleep.
If you are a pet owner, you must have noticed your pets squeaking or making sounds during sleep as if they are dreaming. However, it does not necessarily prove that all animals dream and have certain patterns.
To prove this theory, we have come across different research conducted by scientists. One such research at the Massachusetts Institute of Technology has concluded that animals have complex dreams and can recall patterns of events or what they have faced in their sleep.
In an experiment, Matthew Wilson, associate professor of brain and cognitive sciences at MIT and Biology graduate trainee Kenway Louie trained rats to run around a circle for a reward. Afterwards, they monitored the animals’ brain activity during the task and in different stages of sleep.
The brain area of animals that stores memory is the hippocampus. It was seen that they create a distinct pattern while the rats are running.
A similar pattern was also observed in half of the REM (Rapid Eye Movement) episodes in the rats’ sleep. Humans generally dream when they are in the REM phase of sleep.
The experiment on the rats showed similarities between the sleep patterns, and the researchers concluded that they were dreaming of running or standing still. This also led to the theory that animals are also, like humans, able to perceive thoughts and store their previous experiences.
In the case of humans, we know that dreams occur during the REM phase of sleep. The signals transmitted by neurons while in REM sleep were measured using electroencephalography (EEG) on the scalp. The large collective movement of electrons indicates electrical imbalances in the brain’s surface. It implies that fast changes of potential difference occur in larger brain portions.
This pattern is much like the pattern observed during active periods, indicating that some parts of the brain stay active while all other body parts are paralyzed.
Looking into the case of REM sleep in animals, it can be seen that all amniotes (animals that develop in amniotic sacs), including all reptiles, birds and mammals, experience deep sleep phases. Birds and mammals spend considerable time in REM sleep, and researchers have proved that their brains remain active during this period, just like humans.
However, mammals stay longer periods of time in the REM phase, allowing them more time for dreaming. Hence, it is assumed that humans and all kinds of mammals are the most prolific dreamers.
It is difficult to categorize and objectify all kinds of dreams animals may have as they intercept their surroundings differently than us. However, the progression and experience of animals’ dreams are just as repetitive as our own dreams.