Counting Sheep: The Science and Pleasures of Sleep and Dreams. Paul Martin

makes no difference if they have had unlimited sleep. If you want to enjoy a few drinks without wilting, make sure you sleep properly the night before.

      Another common experience is that the effects of alcohol vary according to the time of day when it is drunk. This happens because alcohol reinforces our natural circadian rhythm in sleepiness, exaggerating the troughs in alertness that normally occur in the early hours of the morning and again in the afternoon. Alcohol consumed at lunchtime or in the early afternoon therefore tends to have a bigger impact than the same amount consumed in the early evening, when alertness is normally higher. Lunchtime boozing really is more likely to make you fall asleep at your desk or crash your car than those pre-dinner ‘sharpeners’.

      Scientists have also uncovered some intriguing parallels between sleep deprivation and the normal ageing process. As we grow older, our performance declines on many psychological and neurological measures. A similar pattern of deterioration is observed in young people after sleep deprivation. One experiment found that after 36 hours without sleep, adults in their twenties had a performance profile similar to that of non-sleep-deprived people aged about 60. So, if you are in your twenties and you want to know how it feels to have the brain of a healthy 60-year-old, just stay up all night. Then you will know. The reason why ageing and sleep deprivation exert similar effects may be because they both impair the functioning of the prefrontal cortex, a region of your brain that is extremely active when you are awake.

      To complete the three-way permutation, alcohol and old age make an unpleasant cocktail. Being old is generally bad for sleep, and so is being an alcoholic. Being old and alcoholic is even worse. The elderly are more prone to insomnia, as we shall see in a later chapter. Alcoholism is also accompanied by sleep problems. And when old age and alcoholism combine within the same person they reinforce their malign influences on sleep. Researchers have found that older alcoholics have significantly worse sleep problems than younger alcoholics.

      Sleep, or lack of it, can also affect physical appearance – a belief encapsulated in the term ‘beauty sleep’. Although sleeping all hours will not necessarily make you more beautiful, prolonged lack of sleep will detract from your physical charms. Animals that have been experimentally deprived of sleep for long periods develop unsightly skin disorders. Lack of sleep in humans, especially adolescents and young adults, might exacerbate skin problems such as acne. Sleep deprivation weakens the ability of the skin to maintain its normal protective functions as a barrier against dirt and microbes. That said, the scientific evidence for a direct causal link between sleep and an unblemished complexion remains sparse, Sleeping Beauty notwithstanding.

      Lack of sleep probably does contribute to the depressing tendency of men to become pot-bellied and flabby in middle age. In men (but not women) almost the entire day’s production of growth hormone within the body occurs during sleep. The less sleep a man gets, the less growth hormone his body produces. As part of the normal ageing process, the total amount of sleep and the production of growth hormone both decline in parallel. Scientists have suggested that this age-related fall in growth-hormone production could be responsible for the systematic replacement of muscle by flab, better known as middle-aged spread. If so, dwindling sleep might be an important ingredient in the expanding waistline, double chins and spindly legs that help to make male middle age such a joy.

Champion wakers

      I’ll wake mine eyeballs out.

      William Shakespeare, Cymbeline (1609–10)

      What happens to people if they get no sleep at all for a long time? One of the first scientific experiments on sleep deprivation dates from 1896, when Professor G. T. W. Patrick and his colleague Dr Allen Gilbert of the Iowa University Psychological Laboratory kept three volunteers awake for 90 hours. Patrick and Gilbert charted the now classic signs of prolonged sleep deprivation, including progressive deteriorations in reactions, memory and sensory acuity, together with a decline in body temperature.

      Their first experimental subject, an assistant professor at the university, suffered his worst fatigue during the second night. Like Charles Lindbergh, he found that dawn was the cruellest time. He experienced visual hallucinations in which the air seemed full of red, purple and black dancing particles like gnats. All three subjects gained weight during the experiment, but their muscular strength diminished as they became more fatigued. The most noticeable effects were on mental performance: their memory became highly defective and they lost their ability to pay attention. One subject failed to memorise in 20 minutes material that he would normally have committed to memory in two minutes. In all cases, the symptoms disappeared after the experiment.

      The first person to become internationally famous for self-imposed sleep deprivation was an American disc jockey called Peter Tripp, whose other claim to fame was inventing the Top 40. In 1959, Tripp managed the feat of staying awake under supervision for more than eight days and nights, a total of 201 hours. He did it to raise money for charity. Tripp even managed to broadcast live during his marathon, from a booth in Times Square, New York.

      Peter Tripp suffered. As time went on, his friends and invigilators found it harder and harder to keep him awake. Constant vigilance was required to prevent him from lapsing into microsleeps. Three days into the experiment, Tripp became abusive and unpleasant. After the fifth day he progressively lost his grip on reality and started to experience visual and auditory hallucinations. His dreams broke through into his waking thoughts and he began seeing spiders in his shoes. He became paranoid and thought people were drugging his food. At one point he ran into the street and was nearly knocked down. These disturbing psychological symptoms were accompanied by physical changes, including a continuous decline in body temperature. By the last evening, Tripp’s brain-wave patterns were virtually indistinguishable from those of a sleeping person, even though he was apparently still awake.

      After 201 hours of continuous wakefulness Tripp had broken the record and halted the experiment. He immediately fell into a deep sleep that lasted 24 hours. When he finally did awake, his hallucinations had gone and he felt relatively normal. But something seemed to have changed within him. Those close to Peter Tripp felt his personality had altered permanently, and for the worse. His wife left him, Tripp lost his job and he became a drifter. Tripp’s marathon of sleep deprivation certainly did him no good, but it was probably not the sole cause of his subsequent decline and fall. Tripp was taking large doses of Ritalin, an amphetamine-like stimulant drug, to keep himself awake during the marathon, and it is possible that the drug, combined with the sleep deprivation, helped to stimulate his paranoid delusions and hallucinations.

      A few years later, Tripp’s record was broken by a 17-year-old high-school student from San Diego called Randy Gardner. In 1965 Gardner stayed awake for 264 hours (or 11 days) in a successful attempt to break into The Guinness Book of Records. Scientists from Stanford University monitored most of his marathon. During the first two days Gardner’s friends helped keep him awake and he did not use caffeine or other stimulants. By the end of the second day he was suffering from blurred vision, making it difficult for him to read or watch TV. By the third day he was irritable and wanted to be left on his own. His speech became slurred and his movements uncoordinated. On the fourth day he experienced memory lapses and mild hallucinations. After nine days without sleep he was unable to complete sentences and had lost the ability to concentrate. On the eleventh and final evening he had double vision.

      Despite these temporary but unpleasant symptoms, Randy Gardner suffered remarkably few ill effects. Having stayed awake for 11 days and nights, he went to bed and slept for nearly 15 hours. When he awoke he felt fine. The following night he slept only slightly longer than usual, and within a few days his sleep had returned to normal. He did not go mad and, except for mild hallucinations, he never displayed any psychotic symptoms during the experiment. The experiences of Randy Gardner and others have demonstrated that going without sleep for several days does not generally result in mental illness or other long-term damage.

      Some feats of self-imposed sleep deprivation have been endured for purely financial reasons, with not a single scientist in sight. In the depression-era USA of the 1920s and 1930s, a bizarre fad developed for dance marathons,