Many people feel that dream is unique to humans. However, many dog owners will likely disagree on that. They have noticed that their dogs at various times during the sleep may shake legs, snort (哼) and sometimes growl (低声吼叫) which gives the impression that they are dreaming. These things may wonder us about whether dogs dream.
Scientists confirm that dogs probably do dream. It turns out that dog brains and human brains have many similarities during sleep cycles. Researchers used special machines to measure electrical activity in a dog's brain and human's brain. Scientists already knew that when humans dream, a certain part of the brain is active during sleep. Researchers discovered that the same part of the brain is active in sleeping dogs. Scientists have other data that back up these findings.
Many people dream that they are trying to move but cannot. Interestingly, part of that experience is not a dream. When people sleep, the brain produces a chemical that causes the dreamer to become temporarily paralyzed (使麻痹). Researchers think this happens so that people cannot physically act out dreams while they are sleeping. Dog brains make the same chemical. In one study during which this chemical was blocked, sleeping test dogs performed physical activities, such as standing up, sniffing around the room for imaginary rabbits, or chasing imaginary balls.
Because of these similarities, researchers believe that the content of a dog's dream might come from the same source as a human's dream. "People's dreams are usually based on things they did that day," says Dr. Samantha Hudspith. "So there is reason to believe that dogs dream about the things they've done that day. Of course, there will never be a way to prove this. Dogs cannot describe their dreams the way that humans can."
