Awakenings in sleep

The story of sleep and dream research began in 1953 with the discovery by Eugene Aserinsky and his professor, Nathaniel Kleitman, at the University of Chicago, that rapid eye movements (Rem) occur periodically during sleep. Further, with the finding that sleepers reported vivid dreams when awakened during rapid eye movement periods, the field of sleep research was truly born. Finally, one could collect dream reports at will by awakening sleepers when rapid eye movements appear. Dreams were so equated with this "new" phase of sleep that "dream sleep" became a synonym. "Classical" sleep with large, slow brain waves was labelled as an afterthought, "non-Rem" sleep.

Enter now Michel Jouvet, of Lyon, who has written a fascinating, sometimes witty account of his wide-ranging studies of sleep, offering his insights into the mystery of dreams. He is rather good at explaining complex physiological concepts so that the curious reader will easily follow him. While most call Rem the "new" phase of sleep, Jouvet sticks with his original appellation, "paradoxical sleep". And paradoxical it is, for many of the physiological variables recorded resemble those in alert wakefulness, yet a person (or animal) is asleep and, what is more, paralysed. This last finding was Jouvet's first contribution; and, like so many important discoveries, it was discovered by chance. He and a colleague were studying the effect of sounds on muscle activity in the neck muscles of cats, which contract as part of the startle response after an unexpected noise. Recording continuously, they noticed a periodic paralysis of the neck muscles when rapid eye movements appeared in animals with only the hindbrain intact. The same paralysis occurred in normal cats. Jouvet soon realised that paradoxical or Rem sleep is quite different from the rest of sleep: it is truly a "third" state. Until then, the field regarded Rem sleep as a light phase of sleep, but Jouvet's and others' experiments have shown it to be quite different and truly paradoxical. Pier Luigi Parmeggiani has demonstrated that even the tight control of bodily functions by the brain is relinquished during paradoxical sleep. Essentially, we are defenceless during paradoxical sleep.

Jouvet covers a lot of ground, not only in this book but also in his research, literally and figuratively. Primarily a neurophysiologist, who has been at the forefront in unravelling the complex mechanisms regulating sleep and wakefulness, he has also ventured out to many areas of the world seeking to understand sleep mechanisms and the dreams they clearly must produce. Working on his hypothesis (central to the book) that through dreams we protect and maintain our genetically programmed individuality from the daily bombardments of our environments, he travelled to Africa. There he found that a certain tribe had very few rapid eye movements during Rem sleep, but his sample size was too small to convince a journal to publish the findings. This did not dissuade him from another attempt, this time in Norway's Lapland. Rather than a rejection letter from a journal editor, he received threats of a barrage of bullets from a group of nationalist Laplanders who considered his project racist. I reject some of his ideas, too, but on different grounds. I side with those who think dreams of Rem sleep are but one expression of dreams and that dreaming does occur in non-Rem sleep. However, this does not detract from my enjoyment in watching a brilliant mind at work.

Jouvet tells other stories with equal wit as he wends his way through his more than 40 years in sleep research, too much to recount in this short review. The book is primarily a collection of previously published articles so there is some wending back and forth on the path; but this is not a defect: the novice can catch his breath and reflect a bit on what he has learned. My own research interests have intersected with Jouvet's more than once, yet I was astonished at how much I did not know about him - I was already aware, though, of an articulate humility in the face of the unknown. His last chapter, which reflects on the progress he has witnessed and looks to the future, ends appropriately: "The next generation will be astonished at our blindness, not realising that it, too, is blind to its own blindness."

Adrian R. Morrison is professor of behavioural neuroscience, University of Pennsylvania at Philadelphia, United States.