Friday, April 24, 2009

Dogs Don't Know What Dreams Are

What do dogs dream about? Chasing rabbits, or something similar, we assume. Dog brainwaves during sleep show rhythms similar to ours, including REM periods during which dreams occur. So it is a reasonable guess that dogs have dreams.

I saw a video clip of a dog having a dream. It is embedded in this inane “news” report (as of 4/21/09):

The dog is asleep, lying on its side, when its feet start twitching. The feet and legs move faster, and become increasingly energetic until the dog looks like it is running full stride about as fast as it can. The forepaws reach out and the back legs push off powerfully. This is a dog in full pursuit!

Then the dog gets up on all fours, and still asleep, or mostly asleep, barks, and bounds headlong into a wall. The dog falls down, gets up again and looks around dazed and confused. It’s a humorous video.

But the interesting part is that dogs don’t know what dreams are. They have limited conceptual capacity, certainly nothing that would enable them to understand the difference between dreaming and wakefulness. Children may have the same problem until caregivers instruct them on the difference. “Don’t be afraid, it was only a dream; It wasn’t real.” Nobody tells the dog that.

From the dog’s point of view it was, for all psychological purposes, actually in pursuit of some prey when suddenly a solid wall intervened. What kind of world is that to live in? That’s a world that makes no sense. Yet what can the dog do but accept it? That is just the reality of the dog’s experience.

Normally, during REM sleep (dream sleep), the musculature of the body is paralyzed (REM atonia). Signals from the somatosensory cortex are damped so we do not act out our dreams. In abnormal cases, a person might partially act out a dream, such as by sleepwalking or sleep talking. But normally, the brain inhibits the action signals so that doesn’t happen.

This video showed what looked like an older dog, and it is likely that his brain was not functioning properly, not inhibiting his bodily action during REM sleep. A few twitches might be normal, but such vigorous acting out of a dream is an abnormal occurrence.

Even for us, from inside the dream, the activity of the somatosensory cortex is the same as it would be in waking experience, so the dream seems “real.” It IS real, as far as it goes, because the same brain circuits are being used as would be used in waking life. But without feedback from the body, those action signals don’t have normal consequences, so you might find yourself flying through the air or walking through walls. As far as the brain is concerned, it is just another experience.

Why dream? There are theories that say the dreamer needs to work through psychic conflicts, express subliminal id impulses, and so on. The dream therefore serves a psychic need. But it seems implausible that a dog has repressed sexual urges or familial tensions. It is more likely that the dog’s dreams (and our own) are simply attempts to interpret the brain’s REM-phase activity as waking experience.

The dog does not think, “Aha! Rabbit! Must catch!” The meaning is automatic. Dogs chase rabbits; that's it.

For the dog, there is no difference between chasing a dream rabbit and chasing a real rabbit. In the dream, joyfully chasing the rabbit over hills and vales, that is just as valid and real as any other experience in the dog’s life.

After waking, the dog does not think, “I wonder why I feel tired and sore, when just a few minutes ago I was chasing that rabbit all over creation.” The dog cannot think like that and is oblivious to the question. The dog does not think, “Hey, what happened to that beautiful field I was just in? How did I get into this dingy, stuffy room?” Again, ignorance is bliss . Dream and reality are not even alternate kinds of experience for the dog. They are just two experiences that happened. Nothing is reasonable or unreasonable for a dog.

Why isn’t it that way for us? We are extremely keen on making a distinction between what is real and what is only a dream. It doesn’t matter to the dog. Why does it matter for us?