The Wandering Mind

by Michael C Corballis

  Sensory deprivation

  Hallucinations frequently occur when normal sensory input is removed or reduced, as though the brain invents an imaginary world when the real world is shut off, just as it does when you dream at night. One form of sensory deprivation is blindness, and people who have lost their sight often have visual hallucinations. These make up what is known as Charles Bonnet syndrome, named for the Swiss naturalist who became interested in the ‘visions’ his grandfather Charles Lullin experienced as his eyesight deteriorated. These hallucinations were quite florid. Once, when two of his granddaughters came to visit, Lullin saw two young men appear in magnificent red and grey cloaks, and wearing hats trimmed with silver. When he exclaimed on their presence, his granddaughters said they saw nothing, and the two men dissolved. As my eyesight deteriorates, I expect to see my twin granddaughters, now aged four, with equally handsome young men in attendance—but they’d better be real.

  Charles Bonnet syndrome was once considered rare, but it is now known that some 15 per cent of elderly patients with deteriorating vision have complex hallucinations, made up of people, animals, or scenes. As many as 80 per cent see more diffuse shapes, colours, or patterns, which perhaps arise from random activity in the visual cortex itself. Deprived of normal input, the restless visual brain stirs up its own mischief.

  Deafness can also result in hallucinations, typically of music, but occasionally of other sounds, such as birdsong, bells chiming, a lawnmower. Unlike visual hallucinations, musical hallucinations are generally true to reality. They can be highly detailed, with every note and every instrument distinctly heard, although sometimes only a few bars are hallucinated, played over and over. Oliver Sacks mentions a patient who heard part of ‘O Come, All Ye Faithful’ nineteen and a half times in ten minutes, timed by her husband. Another patient, a violinist, hallucinated one piece of music while actually performing another piece at a concert. These hallucinations, though, are not so much replays of previous episodes as repeats of well-known and no doubt often repeated experiences.

  Hallucinated music is like the earworms mentioned in Chapter 1, persistent and hard to dispel, but generally more vivid and true to life, with a level of detail and accuracy that may astonish the hallucinator, who in some cases is normally unable even to hold a simple tune. The seeming reality of hallucinated music is illustrated by a woman who wrote to Sacks:

  I kept hearing Bing Crosby, friends and orchestra singing ‘White Christmas’ over and over. I thought it was coming from a radio in another room until I eliminated all possibilities of outside input. It went on for days, and I quickly discovered that I could not turn it off or vary the volume.

  Another partially deaf 60-year-old woman heard persistent music as though from a radio at the back of her head, including one song that played repeatedly for three weeks before another song took over. She did not even recognise many of the songs she heard, but was able to hum the tunes, which were then identified by members of her family. These songs were evidently buried deep in her memory, but were somehow able to surface only as hallucinations. Aside from her partial deafness, she showed no evidence of neurological or physical disorder.

  You don’t need to be blind or deaf to suffer from sensory deprivation. People held in cells or dungeons may seek some consolation in what Sacks calls ‘the prisoner’s cinema’, made up of hallucinations and dreams. Visual monotony can also do the trick. Sailors, polar explorers, truckers and pilots are all prey to visual hallucinations, which can sometimes be hazardous. The poet Samuel Taylor Coleridge, himself somewhat driven by drug-induced hallucinations, captures something of the hallucinatory life of a sailor in his 1798 poem The Rime of the Ancient Mariner: ‘Yea, slimy things did crawl with legs / upon the slimy sea.’

  At McGill University in the 1950s, researchers paid people to stay in soundproofed cubicles, wearing gloves and translucent goggles to cut down stimulation, for as long as they could bear it. At first they fell asleep, but when they awoke became increasingly bored, craving stimulation. Soon their brains provided it, with hallucinations that grew progressively more complex, culminating in quite elaborate scenes. One saw a procession of squirrels marching across a snowfield; another prehistoric animals walking about in the jungle. In later studies, volunteers were floated in tanks of warm water, effectively removing all sensory input. This austere environment rapidly induced hallucinations, and in the 1970s the tanks became avidly sought after as consciousness-expanding drugs.

  Hallucinations induced under sensory deprivation can also be shown to differ from normal visual memories in terms of the brain areas involved. A group of researchers in Germany persuaded a woman artist to be blindfolded for 22 days, so that she experienced visual hallucinations. While blindfolded, she also had several sessions in an MRI scanner, and was able to indicate when her hallucinations came and went. The scans revealed activity in her visual system precisely linked to the hallucinations. Afterwards, she drew illustrations of some of the hallucinations, and when she was asked to conjure them up in imagination the visual areas were not activated. In the absence of visual input, we seem to be unable to intentionally activate the parts of the brain that give us truly visual experiences, but hallucinations can do it for us.

  Drugs

  The fastest way to hallucinate is to take hallucinatory drugs—‘transcendence on demand’, as Oliver Sacks puts it. So great is the human flirtation with drugs that we have evolved a symbiotic relationship with nearly 100 plants with psychoactive substances. It seems they may need us as much as we need them, perhaps not so much for their mind-expanding properties as for the sense of euphoria they supply. We should not take full credit for the existence of these plants, though. Some plants have evolved psychoactive agents to deter predators, or to entice other animals to eat the fruit and spread the seed. And we humans have gone beyond plants to synthesise new hallucinogens.

  In the 1890s, western people discovered peyote, also known as mescal, a cactus with psychoactive properties that had probably been used for over 5000 years by Native Americans in religious rituals or as a medicine. One who described its effects was Silas Weir Mitchell, a distinguished American physician. At one point he took a solid dose, went on several house calls, and then settled in a dark room, closed his eyes, and experienced ‘an enchanted two hours’. These included vivid arrays of colour and light, a grey stone that grew to a great height and became an elaborate Gothic cathedral, clusters of huge precious stones or coloured fruits—‘all the colours I have ever beheld are dull as compared to these’.

  In his 1902 book The Varieties of Religious Experience, William James refers to the case of a Mr Peek, perhaps a forebear of the savant Kim Peek, who wrote as follows of his mescal-induced experience:

  When I went in the morning into the fields to work, the glory of God appeared in all his visible creation. I well remember we reaped oats, and how every straw and head of the oats seemed, as it were, arrayed in a kind of rainbow glory, or to glow, if I may so express it, in the glory of God.

  Mescal and other hallucinogens seem to zero in on regions of the brain involved in vision, and especially the perception of colour, as well as inviting religious experience.

  Oliver Sacks was himself an enthusiastic player in the drug culture of the 1960s, the era of the Beatles’ song ‘Lucy in the Sky with Diamonds’, composed as a celebration of the drug lysergic acid diethylamide (LSD). He started with cannabis, which gave him an experience that was ‘a mix of the neurological and the divine’. He moved on to Artane, a synthetic drug allied to belladonna, and it was this that produced the hallucinatory visit of his friends Jim and Kathy, described earlier. Shortly after he had eaten the ham and eggs he had cooked for his absent guests, he heard a helicopter, bringing his parents for a surprise visit. Amid the deafening roar of the helicopter landing beside his house, he quickly took a shower and changed his clothes. You know the rest—there was no helicopter, no parents. Just a sad Sacks.

  He later developed a cocktail of drugs
made up of amphetamine, LSD and a pinch of cannabis. He wanted especially to see the colour indigo, which Isaac Newton had rather arbitrarily included in the colour spectrum. After taking his cocktail he faced a white wall and demanded: ‘I want to see indigo—now!’ He was rewarded by ‘a huge, trembling, pear-shaped blob of the purest indigo’. It was, he thought, the colour of heaven. This seems to have been a rare example of a hallucination at least partly under the control of the hallucinator—he asked for it, and got it. But his continued experimentation with drugs turned the heaven into hell. The hallucinations themselves turned unpleasant and frightening, his sleep was disturbed, and he developed delirium tremens. With the help of his friend, the American actress Carol Burnett, he managed eventually to escape the addiction and pursue his career as a successful author and neurologist.

  Hallucinations are indeed remarkable in expanding consciousness. So are dreams, which might themselves be regarded as hallucinations wrought by sensory deprivation, although their connection with the rhythms of nocturnal eye movements suggests that they are natural events. All cultures have had their obsessions with hallucinogenic agents, as though there is a human imperative to explore the boundaries of the mind beyond what life normally provides. It is hallucinations, perhaps, that fuel religions, providing a sense that there is more to existence than the daily routine, and the foreboding that life is temporary. ‘[A]ll our yesterdays’, says Macbeth in Shakespeare’s play, ‘have lighted fools / The way to dusty death.’

  Drug-induced hallucinations seem largely visual, but an exception is provided by Evelyn Waugh in his semi-autobiographical novel The Ordeal of Gilbert Pinfold. Waugh was a heavy drinker, and in the novel his alter-ego Gilbert Pinfold tries to cure his woes by adding a strong sleeping potion of chloral hydrate and bromide to his regular intake of alcohol. He then decides to take a restorative cruise to India. He runs out of the sleeping potion but continues to drink heavily. Then the hallucinations begin. They are exclusively auditory—mostly accusatory voices, but also music, a barking dog, a murderous beating, and phantom shipboard sounds. The hallucinations become increasingly preposterous, and are accompanied by delusions that his persecutors have machines than can read and broadcast his thoughts. All the while, though, he sees the world and his shipboard surrounds as normal.

  In western society at least, alcohol has been for the most part the drug of choice. William James commented that ‘the sway of alcohol over mankind is unquestionably due to its power to stimulate the mystical faculties of human nature, usually crushed to earth by the cold facts and dry criticisms of the sober hour’. James was evidently referring to the effects of drinking to excess; a glass of good red wine seems harmless enough, and perhaps even good for your health. Prolonged heavy drinking can take you beyond mysticism to delirium tremens, with uncontrolled trembling and hallucinations, as the tale of Gilbert Pinfold suggests. And even when you stop drinking, the withdrawal effects can persist and even grow more extreme. Cheers.

  Hallucinations and dreams can take us into regions of the brain that are inaccessible to the conscious will. Our normal mental time travels cannot reproduce the actual experiences on which they are based. By the same token, though, hallucinations don’t recapture our exact memories or plans for the future. Perhaps, then, there is a trade-off between the two. During the waking, working hours, we need imagination to be kept in check, so that we don’t stray too far from real-world constraints and perish in dreams of immortality or delusions of being superhuman. During the night, or when the sensory world is cut off, the brain takes the opportunity to recharge, and challenge its own limits—much as marathon runners or mountaineers try to challenge their bodily limits. Dreams are a natural part of life’s cycle; drugs more of an aberration, an open invitation into a promised heaven but an eventual hell.

  It is also remarkable that hallucinations can activate the perceptual systems themselves, so that we see and hear hallucinations as being real. Yet we are accustomed to thinking of perception as driven by the world, through its impact on the bodily receptors—our eyes, ears, noses, organs of touch. The extent to which hallucinations and dreams can invade perceptual systems may suggest that perception is fundamentally driven from within, with information from the world serving merely to guide what we see, hear and smell. Perhaps that’s an exaggeration, but hallucinations tell us that there’s more to perception than meets the eye.

  9.

  THE CREATIVITY OF THE WANDERING MIND

  …

  Creativity is just connecting things. When you ask creative people how they did something, they feel a little guilty because they didn’t really do it, they just saw something. It seemed obvious to them after a while. That’s because they were able to connect experiences they’ve had and synthesize new things.

  —Steve Jobs

  The brain is never inactive, the mind never still. For at least half of our lives, our minds are wandering away from the chores of life—the homework, the tax return, the board meeting, the meal to be cooked, even driving the car. During our waking hours, episodes of mind-wandering arise spontaneously, but we do exercise some control over where our wanderings take us, whether brooding over some past incident, planning some future one, working on the crossword clue, or wondering what our kids are doing or thinking about. While we’re asleep, though, the mind wanders with predictable frequency in the form of dreams, but with unpredictable content. We have virtually no control over what we dream about, although we may mentally act within a dream with some degree of influence—although as often as not our dreamed intentions seem to be thwarted. Hallucinations are also dream-like, and we can have some influence over their appearance, if not what happens in them, by taking psychoactive drugs or seeking sensory isolation.

  Much of our mind-wandering is told in stories. Indeed, if there is anything special about the human mind it is the capacity to construct intricate narratives, and through language share them with others. These narratives might be recollections of past events, plans for the future, or simply made-up stories of often imaginary people in imaginary places doing imaginary things. So it is that the great oral legends that have shaped pre-industrial cultures were born, as well as the epic poems of Homer, the Bible, the plays of Shakespeare, the novels of Jane Austen or Honoré de Balzac, the detective stories of modern times, the soap operas that extend forever on our TV screens. The mind-wandering itself is in the hands or voice of the teller of the tale; the audience or readership is effectively taken on a guided tour. But that guided tour is itself a wandering of the mind into places and times removed from the present.

  Mind-wandering has something of a bad press. The wandering mind is said to be an unhappy mind, perhaps even setting us on a path to early death. This view is encouraged by the popularity of mindfulness, and other meditative techniques, designed to focus our thoughts so intently that the mind is tethered into near immobility. The distinction between mind-wandering and mindfulness, though, is not absolute. One of the techniques of mindfulness or meditation is to focus attention on the body, starting with the feet and moving slowly upwards. This is indeed a constrained wander, although hardly a walk in the garden or a stroll along the beach. It may well be that mindfulness is a means of resting the wandering mind, energising its resources. But wander it surely will.

  Nature has equipped us to be more than mere robots, locked into specific routines. Our brains have been given the extra resources to escape the here and now and the tasks at hand, and play. Play has evolved because it is adaptive, helping us prepare for life in a complex world. But play itself adds to the complexity, creating a feedback system that enhances our need for further creative play. Perhaps it is this loop that gave us our extraordinary propensity for mind-wandering and the telling of stories. To continue to survive in the complex worlds we have created, we need to allow the mind to wander—to play, to invent, to be creative.

  Creativity

  Something I owe to the soil that grew—

  More to the life that f
ed—

  But most to Allah Who gave me two

  Separate sides to my head.

  I would go without shirts or shoes,

  Friends, tobacco or bread

  Sooner than for an instant lose

  Either side of my head.

  —Rudyard Kipling, from ‘The Two-sided Man’

  So what of creativity? Let’s first dispel the illusion that creativity comes from just one side of our brains—the right side. Google ‘right brain’ and you get some 660 million hits. ‘Left brain’, supposedly the dominant half, collects less than half as many, around 270 million. McGilchrist’s plea that governance be restored to the right brain, the Master, may be well under way. Googling ‘right brain creativity’, moreover, gives around 14.5 million hits. The right brain has even wriggled its way into dictionaries. For instance, the fourth edition of the American Heritage Dictionary of the English Language (2000) gives the following definitions:

  Right-brained adj: 1. Having the right brain dominant. 2. Of or relating to the thought processes involved in creativity and imagination, generally associated with the right brain. 3. Of or relating to a person whose behavior is dominated by emotion, creativity, intuition, nonverbal communication, and global reasoning rather than logic and analysis.

  Remember, too, that according to Julian Jaynes the gods spoke to us through the right brain.