Mexican David M. Peña-Guzmán, a professor in the Faculty of Humanities at San Francisco State University (USA), is a specialist in animal behavior, the theory of consciousness, and the history and philosophy of science. In his new book, "When Animals Dream" (Errata naturae), he explores what goes through the minds of beings as diverse as dogs, cats, octopuses, rats, and elephants when they close their eyes and go to sleep. He claims that they dream and that these dreams, sometimes terrifying nightmares, imply "the presence of a consciousness." There's even a gorilla who narrates them using sign language. "Sometimes, when my cat sleeps in her basket, she shakes, trembles, and moves her whiskers. What's wrong with her?" "Cats spend a lot of time in the REM sleep phase, during which they undergo physiological and neuronal changes that suggest the presence of paradoxical sleep." It occurs when the body of a sleeping animal rests while its mind activates and begins to produce those captivating chimerical images we call 'dreams'. During this period, animals make physical movements in the real world that correspond to the movements they believe they are making in their dreams. Related News standard No The first complete map of the 'wiring' of an insect's brain, a key step in understanding human behavior Judith de Jorge The work shows in detail how neurons connect to each other in the brain of the fruit fly larva —Do all animals dream? —Dream experiences exist in mammals, birds, and fish: some 30,000-40,000 species. But that's not all. We have discovered dreams in cephalopods, especially in squid and octopus, which separated from the evolutionary branch that culminated in Homo sapiens 500 or 600 million years ago. And it has recently been established that some species of spider also exhibit this mental power, which introduces a whole new category to the debate: arthropods. Of course, we must be careful with our hypotheses and consider each species individually. Perhaps there are species of spider or bird that don't dream. What about earthworms, butterflies, or sea sponges? It's still not clear. Are these beings really so 'simple' that they can't open the door to dreaming? Or could it be that we haven't investigated their sensory, cognitive, and social capacities enough to know what they are capable of? Or perhaps our definition of 'dreams' is not flexible enough and is largely based on human criteria? This possibility has already been explored in the case of the bee, with promising results. How can we be sure that an animal is dreaming? —They show us the same signs that we already accept in humans as evidence of sleep: they move their bodies suggestively and present neural activation patterns that have a concrete and revealing meaning. —For example? —In the waking state, rats use their sense of touch to navigate space (using, in part, their whiskers). And we know that when they're exploring a particular place, they have certain neural patterns. The fascinating thing is that when they fall asleep, rats activate their whiskers in an exploratory manner while exhibiting the same brain patterns as when they explore space during wakefulness. They're reliving a past experience in the context of a dream. In other words, they're dreaming. —But many researchers disagree with this. Why is that? —There are researchers who think that science should not enter philosophical territory under any circumstances, given that when it does, it ends up failing and jeopardizing its prestige. Others simply don't consider animals to be beings capable of sophisticated mental acts. From their perspective, animals may have instincts, drives, and needs, but not abilities that take us from biology to psychology, such as thought, imagination, or intentionality. Since dreams are more like the latter, these researchers conclude that animals lack the necessary resources to dream. —What do animals dream about? —There's the case of 'Heidi,' a female octopus living with a scientist in Alaska, who recorded her one day while she slept. And what he recorded was one of the most impressive (but not the only) pieces of evidence of these creatures' dreams. In the video, 'Heidi's' skin changes colors from one moment to the next, like a real movie screen. In some cases, her skin changes texture, alternating between smooth, wrinkled, and spiky. All of these changes are the same ones 'Heidi' would make if she were awake and trying to eat prey, say a crab. Except that here 'Heidi' is asleep, and therefore we can say it's extremely likely she's dreaming about eating an imaginary crab. It's possible that animals, like humans, typically dream about whatever interests them in waking life: eating, surviving, exploring, chasing, fleeing, socializing, etc. —'Heidi', about eating a crab; my cat, perhaps about the bird she caught. —In their dreams, animals relive experiences from their past or live through experiences that are at least influenced by the past. Just as 'Heidi' dreams about doing things that octopuses do, I imagine cats dream about feline things and dogs about canine things. In the dreams of other living beings, we notice emotions like fear, terror, and anguish, but also desire, happiness, and joy. —Does my pet dream about me? —I don't know, but I don't doubt it. Dreams reflect our emotional, psychological, and existential state. When we're sad, we tend to have negative dreams. When we deeply desire something, we obtain it in our dreams; when we experience something shocking and harmful, we are plagued by nightmares. It's not difficult to imagine the same thing happening with animals. And when we talk about animals that live close to humans, like the companion animals that live in our homes, or the animals that depend on zookeepers, or those that live and die in the hellish throes of factory farms, they may dream about us. And not necessarily in a positive way. Post-traumatic stress—Are we in their nightmares?—We know that there are animals, like chimpanzees, gorillas, and elephants, that dream about traumatizing scenes they've experienced at the hands of humans. In these cases, we, humans, are the monsters in other beings' dreams. Perhaps we should ask ourselves: Who am I in the dreams of the animals with whom I share a home, a life, a world, a universe? How will I be judged by the dreams of others? —In the book, you tell a terrifying story: that of a baby elephant in a Kenyan orphanage. —When he was just a baby, the elephant 'Ndume' and his family wandered into a farm field while trying to escape the effects of deforestation. There, they encountered a group of farmers who wanted to protect their crops. The conflict culminated in several injured elephants and others killed. 'Ndume' was beaten unconscious. When he awoke, his family had disappeared and he had been rescued by a group of activists. —It's a horrifying scene. —The trauma was so intense that 'Ndume,' now an orphan, began to suffer from chronic nightmares. He couldn't sleep at night, and when he finally managed to doze off, he would wake up in a panic, twitching his voice. Viewed from a psychological perspective, his nightmares meet the criteria for post-traumatic stress disorder, a medical category that developed in the 20th century through the study of trauma in war veterans. Like a veteran haunted by harrowing war memories, 'Ndume' suffered from his own past, a primal trauma he experienced firsthand. "The gorilla 'Michael' used signs to tell his keepers about his night terrors: how he lost his mother." —Can animals remember their dreams? —There's a gorilla, 'Michael,' who was separated from his mother when he was a few years old. He then found himself moving from one captive site to another, until he finally ended up in a laboratory at Stanford University in California. There, he was trained to communicate using American Sign Language (ASL). As an adult, he achieved a respectable linguistic level. He recounted his nightmares to researchers, memories of her tinged with violence. His testimony requires interpretation, but he tells of an attack during which his mother (a "girl" chimpanzee) suffered injuries and cuts to various parts of her body, including her face, neck, and mouth. "And can they learn while asleep?" "Humans regularly dream about the problems we have to solve while awake. There is evidence that we sometimes solve these problems in our dreams. The problems can be emotional, social, or even scientific. There have been cases of mathematicians and physicists who say they have found in their dreams the solution to a problem that was overwhelming them, be it an experiment, a calculation, or a hypothesis. At this time, we don't know if this also happens with animals, but in my book, I tell the story of a rat that actually found a solution in its dreams to a problem that presented itself in the laboratory." "What was it?" "A group of scientists placed the rat in a maze with multiple paths." And the rat, in its dreams, invented an original solution by imagining a shortcut that would allow it to move from one path to the other without having to travel from beginning to end. This is an example of a dream solution. There is another very similar case involving a rat that imagined getting a prize that humans placed in a part of the maze that the rat could see but not touch (because there was a barrier). In its dreams, the rat 'solved' the problem by imagining the maze with the prize but without the barrier that prevented it from passing. —Do they have lucid dreams? —It's possible, but we have no evidence. Perhaps they are within reach of a select group of animals: great apes, some mammals, and some birds. The reason is that some of these animals have already demonstrated the same 'metacognitive' abilities that, according to experts, are needed for lucid dreams. —What are the implications of knowing that humans are not the only ones who dream? —Today, we accept without controversy that all human beings have the right to be treated ethically (with dignity, respect, and affection). But this universalism has not extended to nonhuman beings. One of the concepts that has been used to justify it is consciousness, with the idea that only human beings are conscious (whether of ourselves or our surroundings). But the more we learn about animal experience, the more we realize that human beings are not the exclusive owners of consciousness or sentience. Animal dreams are an example. A dream is a mental experience that cannot exist in entities, beings, or organisms that do not have at least a basic level of consciousness. To dream is to imagine, to create, to project. Therefore, the presence of dreams in animals automatically announces the presence of consciousness. This, I think, encourages us to see animals as members of the moral community deserving of consideration. —Do dreams reveal an emotional life? —All dreams have an emotional character, even when this character isn't evident from the outset. If we imagine an extremely simple dream without much complexity, that dream will be felt in some way by the body. It will be felt as something positive or negative, attractive or repulsive. And it will provoke physiological changes in the body that indicate that the body is experiencing an emotional reality. Perhaps this reality will provoke fear. Perhaps it will provoke intense joy. Perhaps it will provoke a feeling of rest and calm. It doesn't matter. What matters is that it will provoke one emotional state or another. Therefore, animals' dreams are windows into their emotional lives. Through their dreams, we can learn new things about their emotions. MORE INFORMATION news No A 'ghost' water reserve of 270 billion tons has been found on the Moon news No And the neutrino fell into the trap —An Animal Welfare Law has just been passed in Spain to improve the treatment of pets. In general, do we treat animals as they deserve? —The Spanish animal welfare law is a good step in the direction of animal protection, although it has its limits. Often, the word 'welfare' is interpreted in legal circles physiologically, as if animal welfare simply consisted of being free from physical injury and having basic needs met (hunger, thirst, shelter). But welfare is more than a medical or biological concept. It's a social and existential norm that has much to do with our state of mind, with the maintenance of our emotional ties, with our position in a social network, with freedom, and even with the value of feeling that one exercises some control over the conditions of one's own life... For example, loneliness may not leave physical wounds, but it weighs heavily and impacts an animal's mental health.
