Mapping the Cerebral: What Are Dreams and Why Are They Essential?

Sleeping beauty by John Collier


Even though it can be explained by a single relevant event in waking life, the series of dreams experienced by the boy I used to be includes a fantastical, metaphorical dimension that places it beyond traumatic memory. If the reactivation of memories is at the root of the cognitive functions of sleep and dreaming, what can explain the symbolic complexity that characterizes the oneiric narrative? It is rare to dream an exact repetition of a waking experience.

On the contrary, most dreams are characterized by the intrusion of illogical elements and unforeseen associations. Dreams are subjective narratives, often fragmented and composed of elements—beings, things, and places—that may or not be familiar, interacting in a self-representation of the dreamer, who generally only watches the unfolding of a story. Dreams vary in intensity, from faint, confused impressions to intricate epics of vivid images and surprising twists and turns. They can sometimes be entirely pleasant or unpleasant, but on the whole they are characterized by a mixture of emotions. They can even anticipate events from the immediate future, especially when the dreamer is experiencing extreme anxiety and expectation, as in the dreams of students on the eve of a difficult exam, which are often filled with details of context and content.

While it may be impossible to map every dream narrative, there is no doubt that dreams do possess certain elements that are typical. Among the classic plots, we find those dreams that are characterized by incompleteness: a moderately unpleasant dream in which we discover that we are naked, unprepared for a test, irremediably late for a meeting, losing our teeth, separated from somebody important in the middle of a journey, looking for them but unable to find them. As for the characters, we often dream about our relatives, our close friends, and people we deal with on a regular basis, though dreaming about strangers is also possible and can even be a frequent occurrence at certain points of our lives.

Any remotely introspective dreamer will certainly remember three basic types of dream: the nightmare, the pleasurable dream, and the dream of the (usually fruitless) pursuit of some goal. The first corresponds to unpleasant situations we don’t have the power to control or avoid. Fear sets the tone for bad dreams, and the nightmare is sustained by the postponing of the feared outcome. Almost nobody experiences their own death in a dream, because we generally wake up before it happens, perhaps because of the great difficulty we have in activating—even in dreams—cerebral representations that are incompatible with a belief in our own lives.

The pleasurable dream is the opposite of the nightmare, presenting gratifying situations stripped of any hint of conflict. This kind of dream often feeds desires that would be impossible in our waking lives, giving the dreamer a complete if unreal satisfaction. But the two extremes of pleasure and terror do not describe most of the dreams we have. Dreaming about such strong emotions requires living through them when awake. It is our memories that give substance to dreams, and nobody dreams without having lived. In the words of Jonathan Winson, one of the pioneers of the neurobiological study of dreaming, “the dream expresses what is happening to you right now.”



Describing one’s dreams immediately upon waking is a simple practice that can enrich one’s dream-life enormously: in just a few days, somebody who never used to remember their dreams can start to fill pages and pages in their dream diary, a device recommended since antiquity as a way of stimulating oneiric recall. The learned Macrobius suggested in the 5th century that oneiric research depends essentially on recording a reliable dream account. In the 20th century, the psychiatrists Sigmund Freud and Carl Jung made the interpreting of these records a new science of the mind: depth psychology.

But one need not spend a lot of time on the psychoanalytic couch to recount and interpret dreams. A little bit of auto-suggestion before sleeping is enough, along with the discipline of remaining stationary in bed upon waking, waiting for Pandora’s prolific box to be opened. The auto-suggestion can consist of repeating, just one minute before sleeping: “I will dream, remember it, and tell it.” On waking, with paper and pencil at hand, the dreamer will first make an effort to remember what they have dreamed. The task will seem impossible at first, but quickly an image or a scene, even if it’s faded, will come to light. The dreamer must cling to this, mobilizing their attention to increase the reverberation of the memory of the dream. It is this first memory, albeit perhaps fragile and fragmentary, that will serve as the initial piece of the jigsaw, or the end of the ball of yarn to be unrolled. Through its reactivation, the associated memories will begin to be revealed.

On the first day this exercise may produce no more than a few scattered phrases, but after a week it is common for whole pages of the dream diary to get filled up, with a number of independent dreams collected upon a single awakening. The truth is, we dream for most of the night, and indeed even when we are awake—though we call that imagination.

Dreaming is essential because it allows us to dive into the subterranean depths of consciousness. As we go through this state we experience a patchwork of emotions. Small challenges and anxieties, modest daily defeats and victories, generate an oneiric panorama that reverberates with the most important things in life, but that tends not to make sense in its entirety. When existence flows smoothly, interpreting the symbolic gobbledygook of the nighttime is no easy task.

Not even the superrich can be denied the right or the fate of being tormented by recurring nightmares, which carry intimate existential meaning. But to somebody who survives just barely on the edge of well-being, to somebody who truly fears for their life, day and night, to the billions who don’t know whether they will have food to eat tomorrow, or clothes, or a place to live, dreaming can be excruciating on a daily basis. In the life of a survivor of war, or a convict, or a beggar, a dream is a roller coaster of affects in garish shades of life and death, pleasure and pain, at the opposite poles of desire.

The Italian chemist and writer Primo Levi, a survivor of the Nazi extermination camp at Auschwitz, told the story of a recurring nightmare he had after his painful return to Turin:

It is a dream within a dream, varied in detail, one in substance. I am sitting at a table with my family, or with friends, or at work, or in the green countryside; in short, in a peaceful relaxed environment, apparently without tension or affliction; yet I feel a deep and subtle anguish, the definite sensation, of an impending threat. And in fact, as the dream proceeds, slowly or brutally, each time in a different way, everything collapses and disintegrates around me, the scenery, the walls, the people, while the anguish becomes more intense and more precise. Now everything has changed to chaos; I am alone in the centre of a grey and turbid nothing, and now, I know what this thing means, and I also know that I have always known it; I am in the Lager once more, and nothing is true outside the Lager. All the rest was a brief pause, a deception of the senses, a dream; my family, nature in flower, my home. Now this inner dream, this dream of peace, is over, and in the outer dream, which continues, gelid, a well-known voice resounds: a single word, not imperious, but brief and subdued. It is the dawn command of Auschwitz, a foreign word, feared and expected: get up, “Wstawàch.”

With the number 174517 tattooed on his wrist, Primo Levi died in 1987 after falling down the stairwell of the building where he lived. The police treated it as a suicide.



The Portuguese word for dream, sonho—from the Latin somnium—can, like its English equivalent, mean many other things, all of which are experienced in waking lives and not during sleep. To have fulfilled “the dream of a lifetime,” “the American dream”—these are phrases people use every day to mean that they are aspiring to something or have achieved it. Everyone has a dream, in the sense of a plan for the future. Everyone desires something they do not have. Why should it be that dream, a nocturnal phenomenon that can evoke both pleasure and fear, is exactly the same word we use to refer to everything we wish for?

Today’s advertising repertoire is in no doubt that dreams are the driving force behind our behaviors, the private motivation for our external acts. Desire is a more precise synonym for that word dream. On one Brazilian radio station, the commercial for the Universal Church of the Kingdom of God makes this quite clear: “This is the place where faith makes dreams a reality.” The strength of the link between dreams and happiness is remarkable. In an advertisement for a credit card in Santiago de Chile, the miraculous promise: “We make all your dreams come true.” In the departure lounge of an airport in the United States, there is a huge photograph of a happy, smiling couple, sailing across a Caribbean Sea on a sunny day. Above it is the enigmatic phrase: “Where will your dreams take you?” Underneath, the logo of the credit card company. One can deduce from the advertisement that dreams are like sailing boats, capable of carrying us to idyllic destinations, places that are perfect, that are supremely… desirable. The equation “dream equals desire equals money” has a hidden variable, which is the freedom to go, to be, and most of all to have, a freedom that even the most wretched can experience in the world of lax rules that is nighttime dreaming, but which in the dreams of daytime are the exclusive privilege of those who are the bearers of a magical plastic card.

Dreaming is essential because it allows us to dive into the subterranean depths of consciousness.

The routine of daily work and the lack of time for sleeping and dreaming, which affects the majority of workers, is a critical part of the malaise of today’s civilization. Although working from home in response to the COVID-19 pandemic may have restored some opportunities for sleep and dreaming, the contrast between the motivational relevance of dreams and their trivialization in the globalized industrial world remains glaring, while its citizens pursue sleep as an elusive prey.

In the 21st century, the search for lost sleep involves sleep trackers, high-tech mattresses, auditory stimulation devices, pajamas with biosensors, robots to help regulate rhythmic relaxed breathing, and a cornucopia of medical remedies. The sleep health industry, a sector that was growing faster and faster even before the pandemic, recently had an estimated value of between 30 and 40 billion dollars. Yet still insomnia reigns. In an era when time is always short, when we wake up every day to the insistent ringing of the alarm clock, still sleepy and already late to fulfill commitments that are renewed infinitely, when so few people remember their dreams because of the simple lack of opportunity to contemplate their inner lives, when insomnia rages and yawning prevails, we have come to a point where the survival of dreaming is called into question.

And yet, we dream. We dream a lot and in bulk, we dream greedily in spite of the city’s lights and noises, in spite of the incessant toil of life and the sadness of our horizon. The skeptical ant would say that anybody who dreams as freely as this is a lazy artist, like Aesop’s fabled grasshopper. At the start of the 17th century, William Shakespeare wrote, “We are such stuff / As dreams are made on.” A generation later, in his play Life Is a Dream, the Spanish playwright Pedro Calderón de la Barca dramatized the freedom to construct our own destinies. Dreaming is imagination with no brakes, and no control, set free to fear, to create, to lose and find.

In his “I Have a Dream” speech, the Reverend Martin Luther King placed the need for racial integration and justice at the center of US political debate. In a country largely constructed by African slaves, their descendants were forced to build the “American dream” but forbidden from enjoying it. The leader of a peaceful but insistent fight for civil rights in the United States, Dr. King was awarded the Nobel Peace Prize in 1964, and was shot dead four years later. King died, but his dream did not, flourishing and progressively opening up a space for the reduction of racial inequality in the country. In the time of President Donald Trump, almost 700,000 people who had arrived in the United States before their sixteenth birthdays, and who had been approved under the Obama-era program for the legalizing of immigrants, became locked in a desperate struggle to remain in the country where they had spent their childhoods and adolescences. Most of these people were born in Mexico, in El Salvador, in Guatemala, or in Honduras. At the time of writing, they are living in limbo, and they are called Dreamers.

A force this powerful needs explaining. What actually is a dream? What use is it? Answering these questions demands some understanding first of how dreaming began and evolved. To our hominid ancestors, the realization that the dream world is an illusion must have been a mystery that was refreshed anew every morning. But the advent of language, religion, and art certainly gave new meaning to dreams’ enigmatic symbols. Curiously, these meanings were very similar in different ancestral cultures. That is an important clue in our attempt to decipher dreams.


Oracle of Night

Excerpted from THE ORACLE OF NIGHT by Sidarta Ribeiro; Translated by Daniel Hahn. Copyright © 2021 by Sidarta Ribeiro. Excerpted by permission of Alfred A. Knopf; Pantheon, a division of Penguin Random House LLC. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.