In 1953, scientists at the University of Chicago observed that people dream much more frequently during certain deep phases of sleep characterised by “rapid movements in both eyes, choppy breathing, irregular heartbeat and fast brain waves”. As the Brazilian neuroscientist Sidarta Ribeiro explains in his new book on the history of dream research, the discovery of what became known as rapid eye movement (REM) sleep had profound implications. Where Sigmund Freud had postulated that dreams are an articulation of our deepest desires, neuroscience seemed to suggest they are in fact “purely random by-products of a strictly physiological underlying reality, and therefore of no psychological significance”; as such, the work of understanding dreams lay beyond the purview of science, “a matter for charlatans, fortune-tellers, priests, psychoanalysts and other professionals in the metaphysics business”.
Ribeiro looks to bridge the gap between neuroscience and psychoanalysis by drawing attention to various studies that suggest a scientific basis for psychoanalytic dream theories. Electrophysiological experiments carried out on rats in 1989, for example, showed that neurons activated while awake were specifically reactivated during subsequent sleep, which supports the idea, advanced by Freud in The Interpretation of Dreams (1899), that dreams constitute a “day residue” – a revisiting of memories and emotions experienced during waking life. Research by the South African neuropsychologist Mark Solms has demonstrated that the brain’s dopaminergic reward system is activated during REM sleep, leading Ribeiro to deduce that “the Freudian proposition that desire is the motor of dreams is much more factual than its critics would acknowledge … Dreaming ‘is’ desire because both ‘are’ dopamine.”
Ribeiro precedes his scientific disquisition with a lengthy survey of notable dreams in politics and culture from antiquity to the modern day. Many of these are premonitory, prophetic or revelatory in nature. We learn that both Xerxes and Alexander the Great were inspired in their expansionist adventures by megalomanic dreams; Julius Caesar’s wife, Calpurnia, foresaw her husband’s demise in a nightmare on the eve of his assassination; when Prince Frederick III of Saxony was asked to extradite Martin Luther to the Holy Roman Emperor after he had torched a papal bull, he declined to do so after having a revelation in a dream, and thereby altered the course of European history. Artists and musicians as varied as Albrecht Dürer, Marc Chagall and Paul McCartney have produced major works inspired by dreams; Samuel Taylor Coleridge’s famous poem Kubla Khan was largely composed during a deep sleep following an opium binge; the chemist August Kekule discovered the hexagonal structure of benzene after dreaming about a snake eating its own tail.
The Oracle of Night contains a number of interesting insights into the science of sleep. These include the intriguing possibility of a link between dreams and psychosis, an idea first mooted by psychiatrists Emil Kraepelin and Eugen Bleuler in the early 20th century and seemingly borne out by investigations into the effects of dopamine on rodents, which indicate that “the mental disturbances of psychosis make the differentiation between fantasy and reality difficult precisely because they are the result of an invasion of waking by sleep”. Another is the discovery, after experiments into sleep deprivation in mice, that sleep helps consolidate memory – meaning people who nod off straight after learning something are more likely to retain the information. Ribeiro believes educationists should therefore adopt a “biologically more intelligent” approach to school timetables, and predicts we will eventually see the introduction of “napping rooms or siesta clubs … [and] individual pods for sleeping” in educational institutions.
“The brain that dreams is the same brain that lives through waking experience”, so it’s unsurprising that there’s a correlation between real-life anxiety and bad dreams: research has shown a high incidence of nightmares among children from conflict-ridden parts of the world such as the Gaza Strip and Kurdistan compared with those in peaceful, northern European cities; studies also indicate a greater prevalence of sleep problems in low-income communities. The recurring vivid nightmares common to PTSD sufferers are an extreme version of this phenomenon: “The memory of the violent event, having been so powerfully codified, is too intense, it possesses very strong synaptic connections, which makes them capture and monopolize the electrical activity produced during sleep.” Ribeiro, a professor at the Federal University of Rio Grande do Norte, is an erudite guide through some rarefied terrain, and Daniel Hahn’s translation from the Portuguese reads seamlessly. That said, the scientific explanations aren’t always easy to follow and the writing occasionally lapses into a specialist register.
The study of dreams is an inherently transdisciplinary pursuit – encompassing neuroscience, biochemistry, psychobiology and anthropology – so offshoots and digressions are to be expected. All the same, a more hands-on editor might have trimmed some of the considerable fat here, which includes, among other things, idle conjectures about the dream repertoires of animals and Palaeolithic people; a segment on the evolution of the earliest multicellular beings; an overview of funerary rites in the Neolithic and bronze ages; a potted history of the concept of madness; reflections on the persecution of astronomers Giordano Bruno and Galileo; a vignette in praise of Bruce Lee; and some personal broadsides on cancel culture and populism.
There are some amusing titbits in among the sprawl, however. The writings of St Augustine of Hippo reveal that the celibate, fourth-century theologian was racked with guilt after having had some steamy sexual dreams. Agonising over whether they constituted a sin, he takes pains to stress that whatever pleasure he experienced while asleep was endured only with the greatest reluctance. The 11th-century French monk Raoul Glaber, whose Benedictine order forbade lie-ins, “left a record of being assailed by a demon whose temptation consisted of whispering in his ear that he should ignore the bell and surrender to the ‘sweet repose’ of the second sleep”.
The bombardment of facts and esoterica gradually gives way to a polemical treatise on the science of the mind, and a through-line of sorts. Ribeiro believes psychiatry lost its way in the second half of the 20th century: when it turned its back on Freud, it essentially turned its back on the whole idea of the psyche; the reduction of human souls to pure physiology – a mere matter of neurons and synapses – has been a boon to big pharma, but it is not serving people well. Ribeiro laments the overmedicalisation of psychiatry and our over-reliance on SSRIs as a mental health panacea, and advocates using psilocybin, ayahuasca and MDMA to treat depression and anxiety. He makes a persuasive case, but one wonders if he could have made it more briskly.