Are Dreams as Vital as Sleep.doc

Are Dreams as Vital as Sleep? by Roger Louis Can dreams be controlled at our own will? Is dreaming the ability of all animals? How do the deaf-mutes and the mentally disabled dream? The following article discusses these issues. Sooner or later biologists were bound to investigate one of the brains most mysterious functions, probably the least tangible and the least comprehensible function of the body, dreaming.Just a few years ago we thought that Freud1, when he took the keys to the city of dreams away from the philosophers and poets, had given them once and for all to the psychologists and psychiatrists2. But now biologists, biochemists and neuropsychologists3 are invading what used to be thought an exclusive preserve.One of these is a Frenchman, Dr. Michel Jouvet, whose research at the medical school of Lyons is internationally recognized as authoritative and on the same plane as that of Professor Nathaniel Kleitman in the United States, which has been continued since 1960 by one of his colleagues, Dr. William Dement. It was more or less by chance that Dr. Jouvet became interested in dreams in 1958, or rather it was the logic inherent in any experimental work that stimulated his curiosity. “I was interested at that time in confirming Pavlovs4 theories of conditioning, using cats as test animals,” he told us. “We had put electrodes in the muscles of their paws in order to check on certain movements.”“During their sleep we noted an unexpected phenomenon that occurred sporadically the complete disappearance of muscular tone, sometimes lasting for several minutes, after which muscular tone reappeared while the animal continued to sleep. “We thought of all possible theories to explain this phenomenon. It even occurred to us that it might be connected with the very special role that whiskers play in the cat, and we actually tried cutting them off to see whether this might have some effect. Only after a long period of groping, did we realize that there was a possible correlation with dreaming. “From that moment our research was directed towards the physiological study of sleep, especially towards what we now call its paradoxical phase. This corresponds to the period in which an animal or a person dreams. “This research was carried out in collaboration with Kleitman and Dement in the United States, among others. In a very short time we were able to collect an extraordinary amount of information and numerous records. “We might begin with the most basic points. By mere physical examination of a person or an animal who is sound asleep, we can now tell whether he is dreaming or not; better yet, we can identify, to within one second, the instant he begins to dream and the instant his dream ends. “We have three basic physiological criteria for this finding, and they are now accepted by all neurophysiologists:1. Virtually complete disappearance of muscle tone.2. Rapid eye movements (hence the term REM sleep), which seem to be without purpose.3. Characteristic brain waves on the electroencephalogram5, quite different from those recorded in deep sleep and very similar to those recorded in the waking state. Discovery of this tracing gave rise to the term “paradoxical phase,” which we apply to sleep in the dreaming state. “We can also state that the average adult dreams about twenty per cent of the time he is asleep, in a number of separate dreams. Each dream episode, about twenty minutes, is preceded by a period of deep sleep, indicated on the encephalographic record by typical long waves.“While we are talking statistics, we might add that the newborn infant dreams much more than the adult fifty percent of his sleeping time and this applies to all mammals. “I might also point out that the capability for dreaming is not an attribute of all animal species. In the evolutionary scale it first appears with birds and with them only to a limited degree about point five percent of their sleeping time. All studies in reptiles and amphibians (e.g. tortoises) give negative results there are no dreams in their sleep.“This gives a brief summary of recent findings, which will enable us to make a detailed study of the problems still confronting neurophysiologists in the phenomena of dreams as well as in the essential function of dreaming. We are now convinced that dreams play an important physiological role, although we are not yet in a position to say just what that role is. One solitary cat was crouched on a brick in the middle of a miniature pool and sleeping peacefully while an electroencephalograph recorded his brain waves. “We keep him from dreaming,” Dr. Jouvet said, “I just explained that one of the recognized physiological criteria of the dream phase in animals is disappearance of muscular tone. This cat can sleep on his brick, but as soon as he begins to dream his muscular tone disappears, and he falls into the water. This at once wakes him up, he climbs back on his brick, licks himself and goes back to sleep but whenever he dreams he falls into the water again. “If we continue the experiment for a week and then put him back in his cage, we observe that he has such a need to dream that, instead of spending only twenty percent of his sleep time dreaming, he will then spend forty percent of it or more. A kind of compensatory mechanism exists somewhere in his nervous system.“For this reason we think that dreaming is not a pointless phenomenon that occurs every time the nervous system goes into free wheeling, but that it reflects a specific activity of the brain and forms an essential part of a process. As to what the process is, that is what we are trying to discover. “In recent times we have made great progress in localizing the centers responsible for the phenomena that accompany dreaming activity. At first we had to proceed by surgical guesswork, successively removing various parts of the brain stem of our experimental animals in order to observe any disturbance in their sleeping behavior. “Sleep itself is a highly complex phenomenon, and it had not yet been decided whether there is a brain center responsible for sleep or whether simple inhibition of the waking centers is what causes it. “However, we have succeeded in precisely pinpointing the centers responsible for the two principal characteristics of dreaming activity: first, rapid eye movement, which we call phase phenomenon and second, the blocking of muscular tone, which is called a tonic phenomenon. Cats in a state of hallucination“Taken together, these two centers are about the size of a pea. They are located very close to one another, but we can influence either one at will by different techniques. The center controlling muscular tone, which is no bigger than a grape seed, lives his dreams. The powerful blockade of muscular tone is no longer effective, so that the sleeping and dreaming animal carries out all the movements that correspond to the action of his dream. An innocent bystander would get the impression that he was wide awake and perhaps dangerous, but in actual fact none of his actions or gestures corresponds to the outside world in which he is moving. He is asleep and he acts only in accordance with the fantasies that are passing through his brain. He is living in an imaginary world he is hallucinating. “As soon as he wakes up, his behavior will become quite normal. “In this experiment you can appreciate the importance of this center: its role in dreaming is primordial. Work is now in progress to study a possible correlation between these hallucinatory states and certain mental illnesses. You might think that sleepwalking would be due to improper functioning of this center, but recent experiments have shown that this phenomenon occurs not during dream periods but in the half awake. People may also talk at this level of sleep not during dreams. “Another related question is whether the weightlessness experienced in cosmic flights may not have unexpected and undesirable effects upon the astronauts insofar as it creates a state equivalent to the absence of muscular tone. It is not a coincidence that the physician chosen to participate in the first trip to the moon planned by the Americans is a specialist in sleep. Dreaming can be regulated at will “But study of the biochemistry of the phenomenon associated with dreams will probably lead to the most fascinating results, and gives us scope to formulate the boldest hypotheses. In the past few years, chemistry has occupied a solid position in the study of biologic phenomena. “Neurohumoral6 processes of the brain are immensely intriguing to present-day research men, who expect to find in them the key to the most complex phenomena. “Hydens studies, to cite one example, convincingly show that biochemistry can open a new point of view on biologic phenomena as complicated as memory. This is also true of our studies on dreaming. The REMs, which appear to be at the origin of the dream stage of sleep, can be blocked or amplified by chemical inhibitors or precursors. In other words, it is possible, by means of specific drugs, to deprive an animal of dreams entirely or to increase them to sixty percent of the time he sleeps. “I can offer only one hypothesis, which is directing our study. It is difficult to verify in the present state of our knowledge, but so far nothing contradicts it. Here it is: dreaming activity is inseparable from other activities of the nervous system. There are not separate states of waking, sleeping, dreaming; these phenomena make up a continuum that is characteristic of certain creatures. In the waking state our nervous system, particularly the brain, perceives a certain number of sensations and records or memorizes them in chemical form by synthesizing molecules of specific proteins. This synthesis takes place through a highly complex process. “This conversion of incoming information into a coded chemical schema is not instantaneous. The chemical factory of our brain needs time to store, select and classify information according to a code that is still to be defined. We might say that the waking state is equivalent to recording information on a dictaphone; during deep sleep this information is typed out; and in the course of dreaming, each page or each sentence, or even each word is classified in a file cabinet along with previous information that is stored away in terms of a careful, previously-established code. “This would explain why our dreams contain numerous images corresponding to impressions received in the waking state, and also why some of this information is completely deformed or symbolized. This synthesis of events of the day in dreams would imply a “trituration” of information, together with a review of previous information already classified and coded. “This hypothesis would also explain why newborn infants and young animals have a high percentage of dreaming time more than twice as much as adults.“I must admit that this hypothesis, although it links dreams to learning and memory, encounters a number of obstacles, it fails to explain why this function suddenly appears in the evolution of species with the bird, to be magnified in a kind of explosion with the mammals. “We must wait some years for the neurophysiologists to carry out further experiments and to interpret them; but it seems to be already well-established that dreams have once and for all left the world of unreality for the world of the laboratory.” 梦与睡眠一样重要吗?罗杰露易丝我们是否能根据自己的意愿来控制梦境?所有动物都会做梦?聋哑人和弱智者是怎样做梦的?下面这篇文章将讨论这些问题。 生物学家们迟早会去探究梦的奥秘，大脑最神秘的功能之一，它可能是难以触摸、无法理解的人体功能。 只是在几年以前，我们以为弗洛依德从哲学家和诗人那儿拿走打开梦境之城的钥匙，并将它们永远地留在心理学家与精神分析学家那儿。但现在生物学家，生物化学家以及神经心理学家正在侵占这片曾经被认为是神圣不可侵犯的领地。 他们其中的一位是法国人米歇尔儒弗博士。他在里昂医学院的研究获得了国际的公认，被认为同美国纳桑尼尔克莱特曼教授的研究一样具有权威性。克莱特曼的研究自1960年以来由他的同事威廉第门特继续下来。 或多或少是由于某种巧合或者是由于某种能引起好奇心的实验性工作的内在逻辑，使儒弗博士于1958年对梦的研究产生兴趣。“我当时对证明巴甫洛夫的调节理论感兴趣，我们用猫作为实验动物”，他告诉我们：“为了核实某些运动，我们将电极植入猫爪的肌肉中。” “在它们的睡梦中，我们意识到了一种出人意料、断续发生的现象-肌肉紧张的完全消失，有时延续几分钟，在肌肉紧张性重新出现之后而这动物在继续睡觉。“我们想到了用各种可能的理论来解释这一现象。我们甚至觉得猫须的特殊作用可能与这一现象有联系，而且我们竟然试着将猫须剪掉，看这是否起些作用。经过长期的摸索后，我们才意识到这与做梦有关。“从那时起，我们的研究转向了对睡眠的生理研究，特别是转向了我们所指的反常阶段。这一阶段与动物或人做梦的时期是一致的。“这一研究同其它研究一起是与美国的克莱特曼和第门特合作进行的。不久，我们就收集了大量的信息与丰富的记录。“我们能从最基本的事情开始。只需对酣睡中的动物或人进行体检，我们就能说出他是否在做梦。更好的是，我们可以确定他开始做梦的时刻与结束做梦的时刻，并且精确到一秒钟以内。“对这一发现，我们有三条基本的生理学原则，而且现在已被所有的神经生理学家所接受：1.肌肉紧张性几乎完全消失2.快速眼动(因此而产生了快速眼动睡眠这一术语)，似乎没有目的。 3.脑电图上特有的脑电波，与酣睡中记录下来的脑电波完全不同，而与醒着时记录下来的脑电波很相似。这种脑波图象的发现导致了“反常阶段”这一术语的现出，这一阶段是指睡梦状态。“我们还可以说，一般成人睡眠时间的20%是在做梦，是一系列分开的梦。每一段梦大约延续20分钟，接着是一阵酣睡，以典型的长波显示在脑电记录上。 “谈到统计数据，我们可以补充说，新生婴儿比成人梦得更多-占50%的睡眠时间-这一数据适应于所有的哺乳动物。 “我还要指出，做梦的能力不是所有动物种类的属性。在演变量表上先是鸟类具有这一能力，并且只是在有限的程度上-占它们睡眠时间的0.5%。对爬行动物与两栖动物(如龟类)的所有研究结果都是否定的-它们的睡眠中没有梦境。“这是对最新发现概述，使我们能够详细研究至今令神经生理学家们苦恼、有关梦的现象以及做梦的基本功能等问题。我们确信，梦担负着一种重要的生理责任，尽管我们还不能说这一责任到底是什么。一只独居的猫蜷缩在小水池中央的一块砖头上，正安详地入睡，同时有一台脑电图仪记录着脑波。“我们不让它做梦”，儒弗博士说“我只是解释，以被公认的有关动物梦境阶段的生理学标准之一是肌肉紧张性的消失。这只猫可以在砖头上睡觉，但它一开始做梦，肌肉紧张性就消失，它就掉进水中。这使它立即醒过来，爬回到砖头上，舔了舔自己又睡着了-但他一开始做梦，又掉进了水里。 “如果我们把这一实验持续一星期，然后将它放回笼子，我们观察到它有做梦的需要，它便会将40%或更多的时间，而不仅仅是睡眠时间的20%来做梦。在它神经系统的某些地方存在着一种补偿性的机理。 “因此，我们认为，做梦不是神经系统进入自由运转时出现的毫无义意的现象，但它反映了大脑的具体活动，形成某一过程的必然部分。至于这一过程是什么，我们正在探索。 “近来，我们在确定引起睡梦活动中伴随现象的神经中枢方面取得了很大的进展。首先，我们为了观察它们睡眠行为中的任何干扰，不得不进行外科方面的猜测，相继去掉实验动物脑干的不同部分。“睡眠本身是一种高度复杂的现象，并且还没有确定是否存在一种负责睡眠的大脑中枢，或者说对醒觉中枢的简单抑制是否是引起睡眠的原因。 “然而，我们已成