So you awoke this morning in a miserable mood. Well, maybe your special dream character didn't put in an appearance last night, or maybe there just weren't enough people drifting through your dreams.

If that sounds like far-fetched fantasy, consider these interesting findings that have emerged from eight years of sleep and dream research at the Veterans Administration Hospital in Cincinnati, Ohio:

While sleep affects how sleepy, friendly, aggressive, and unhappy we feel after awakening, feelings of happiness or unhappiness depend most strongly on our dreams.

Each of us has a special dream character, a type of person whose appearance in our dreams makes us feel happier when we awake.

What we dream at night isn't as important to how we feel in the morning as the number of people who appear in our dreams. The more people, the better we feel.

Our sleep influences our mood. Our mood, in turn, affects our performance. And throughout the day, our levels of mood and performance remain closely linked.

During the past two decades, research has greatly expanded our knowledge about sleep and dreams. Scientists have identified various stages of sleep, and they have found that humans can function well on very little sleep, but only if they dream. Yet the true function of sleep and dreaming continues to elude precise explanation.

In 1970 Milton Kramer and Thomas Roth, researchers at the VA Hospital and the University of Cincinnati College of Medicine, respectively, raised this question: Do our moods in the morning relate in any way to our sleep and dreams the previous night?

Human experience suggests that they do. Certainly we generally feel better after a good night's sleep. But Drs. Kramer and Roth sought a much more definitive answer. And that answer, though still evolving, is positive yes.

Kramer and Roth began by seeking to determine whether one's mood differs between night and morning, and whether this is related directly to sleep. They found that there is a difference, and its is definitely related to sleep. Then they explored the various aspects of mood and their relationship to the various stages of sleep and dreaming.

What does a good night's sleep mean to our mood? Generally we are happier, less aggressive, sleepier, and a bit surprisingly, less friendly. Being sleepier is easily explained. It simply takes a little time to become fully alert after awakening.

But why should we feel less friendly? Here the researchers must speculate a little. They suggest the answer may be the lack of association with other humans during the period of sleep.

Once the two doctors established scientifically what common sense and folk wisdom had long taught - namely, that there is link between sleep and how we feel - they set out to learn what parts of our mood are related to which specific parts of the sleep cycle.

Normal sleep is broken into five distinct parts - Stages 1 through 4, plus REM, an acronym for rapid eye movement. Much remains unknown about each of the five sleep stages. Most dreaming occurs during REM sleep, a period when the eyeballs move rapidly beneath the closed lids. And whether they remember or not, all adults dream, usually four to six times a night.

Three types of mood are strongly related to some specific stage of sleep. Our friendly, aggressive, and sleepy feelings all relate to Stage 2 sleep, which accounts for most of our total sleep hours. Our friendly and sleepy feelings, but not our aggressive feelings, are affected as well by Stages 3 and 4, and by how long it takes us to fall asleep.

This means that if you get less sleep than normal - and people vary a great deal in how much sleep they normally require - you awake more friendly, more aggressive, and less sleepy.

At this point, the doctors found themselves puzzled. They knew from their earlier work that sleep determines if people feel happier. Yet when they studied the various sleep stages, they found no correlation between sleep physiology and the unhappy mood. Clearly sleep made a difference, but that difference didn't relate to how much time one spent in each of the various sleep stages.

The two researchers decided the key to whether we feel happy or unhappy after sleep must lie in sleep's psychological component - our dreams. So they began studying dream content - what dreamers dreamed and who appeared in their dreams - to see how this affected mood.

Instead of sleeping through the night, volunteers now were awakened four times while in REM sleep. They were asked about such things as what their dreams were about; the sex, age, identity, and number of the people in their dreams; and what each person in a dream was doing.

Interestingly, Kramer and Roth found that being awakened four times a night didn't make a difference in the volunteers' morning mood patterns. But they did find that who appears in a dream has a far greater influence on mood than what occurs in the dream. "Who affects all the moods," Kramer says, "but primarily the unhappy mood."

Each of us, it turns out, has a special dream character, and if this type of character appears in our dreams, we are happier when we awake. "For people in general, how unhappy you feel after sleep depends on who is in the dream," Kramer says. "Who it is that makes you happier is different for you than for me." For some it may be an older woman, for example; for others, a young man.

Who appears in your dream isn't the only important thing. The more people who appear in your dreams the happier you are on awakening. It's a case of the more the merrier. "The bad thing in a dream is to be alone; you feel worse," Kramer explains. "You can relate this to wakening psychology, where being alone leads to more unhappiness. There is something about interacting with people that produces happiness."

A number of researchers have examined the relationship of mood and performance. The doctors also checked into this relationship, and they have found some interesting correlations.

"We found that the more friendly, more aggressive, more clear-thinking, less sleepy, and surprisingly, the more unhappy you are, the better you perform. That last one - the unhappy - I can't explain," Kramer says. Moreover, the level of person's moods and the level of his or her performance rise and fall together throughout the day.

Initially the two VA researchers worked only with men, because the dreams of men are far easier to study. Men and women dream differently. Indeed, sex is the biggest factor in accounting for differences in the people activities, locations and feelings that occur in dreams. Dr. Kramer says, "When you compare men and women, you get a greater difference in dream content than when you compare, say, 20- and 60-year-olds, or black and white."

Last year the VA researchers began studying the relationship of sleep, dreams, and mood in women. This work is continuing, but the initial findings reinforce what they had found in men.

"Overall, the women are just like men," Kramer says.

这么说，你今天早上醒来时心情很糟。唔，或许你的特别的梦中人昨夜未曾入梦来，或许只是没有足够的人进入你的梦境。

如果那听起来像靠不住的空想，想一想在俄亥俄州辛辛那提的退伍军人管理医院进行的对睡眠和做梦的八年研究中发现的有趣结果吧。

虽然睡眠影响我们醒来后是否疲倦、友好、好胜、不开心，感觉开心与否主要在于我们的梦。

我们每个人都有一个特别的梦中人，一个在我们的梦中出现、醒来时使我们感觉更开心的人。

在夜里梦到什么对于我们早上感觉如何并不比我们梦里出现的人数更重要。梦中人数越多，我们感觉越好。

梦影响我们的情绪，我们的情绪进而影响我们的行为，一整天，我们情绪高昂亦或低落的行为总是密切相关。

在过去的20年里，研究大大地扩展了我们对睡眠的梦的知识。科学家们已经可以识别不同的睡眠阶段，而且发现，人在睡眠很少的情况下，机体仍然很好的运转，但只是在睡眠时做了梦才如此。而睡眠和做梦真正的功能依然得不到准确的解释。

1970年，VA医院和辛辛那提大学医学院的研究者米尔顿·克莱默和托马斯·罗斯，分别提出了这个问题：我们早晨的情绪与我们前一天夜里的睡眠和做梦有某种关系吗？

人们的经验表明它们是有关系的。当然，在一夜足睡的时候，我们一般会感觉良好。但是克莱默和罗斯医生发现了一个更明确的答案，虽然这个答案仍在逐步形成中，但答案确是肯定的。

克莱默和罗斯开始于探求一个人的情绪在早上和晚上是否不同，是否与睡眠有直接关系。他们发现确实是不同的，也确实与睡眠有关。接着，他们研究了情绪的不同方面和它们的睡眠和梦不同阶段的关系。

一晚的好觉对我们的心情意味着什么？通常我们会更开心、不那么有攻击性、更困倦，而且令人感到有点吃惊的是，居然不那么友好。更困倦的容易解释，只是需要一点时间在醒来后使自己完全清醒。

但为什么我们会感到不那么友好呢？这里研究者得做一些推测，他们认为答案可能是睡眠期间缺少与他人的交流。

两位医生一旦把常识和民间智慧长期教给他们的东西--即睡眠与我们的感觉之间有联系--科学地确定下来，他们就着手了解我们的情绪的哪些部分与睡眠周期的哪些具体部分有关。

正常睡眠可划分为五个不同部分，从第一阶段到第四阶段，加上REM。每一个阶段都有许多人们未知的知识。大部分的梦发生在REM睡眠期间，眼球在紧闭的眼睑下快速移动。不管成年人是否记得，他们都做梦，通常一夜4到6次。三种情绪和睡眠的某一阶段紧密相关。我们友好的、有攻击性的、困倦和睡眠的某一阶段紧密有关。我们大部分的睡眠在第二阶段。我们友好的、困倦的、但没有攻击性的睡眠时间也受到第三、第四阶段以及我们多久才能入睡的影响。

这就意味着如果你比平时睡得少些--在政党情况下需要多少睡眠，人与人之间是有很大差别的--你醒后就会更加友好、更有攻击性、少些困倦。

在这一点上，医生们自己也感到困惑。在他们以前的研究中，他们知道睡眠决定着人们是否会更高兴。然而，当他们研究各个睡眠阶段时，他们发现在睡眠的生理状况和忧郁的情绪之间没有关系。很显然，睡眠会带来差异，但是这种差异与人们花在每一睡眠阶段的时间长短没有关系。

两位研究者断言，睡眠以后我们是否感觉高兴的关键肯定是取决于睡眠的心理构成部分--我们的梦。所以他们就开始研究梦的内容：人们梦到了什么、谁大梦中出现--来弄清楚梦会怎样影响到情绪。

参加试验的志愿者不能整夜睡眠，相反，在REM睡眠中，他们被唤醒四次，然后回答问题，如他们梦的内容、梦中人物的性别、年龄、身份和数量，以及梦中每一个的所作所为。

令人感兴趣的是，克莱默和罗斯发现一夜被唤醒四次并没有使志愿者早上的情绪模式发生改变。但他们却发现谁出现在梦中比梦里发生什么事对情绪具有非常大的影响。"梦中出现的人物影响着所有的情况，"克莱默说，"但首要的是不高兴的情绪。"

结果是我们每一个人都有一个特殊的梦中人物，如果这个人出现在梦中，我们醒后就会感到很高兴。"对一般人来说，这个人可能是一位老太太，对另外一些人来讲，可能是一位年轻男子。"

谁出现在你梦中并不是唯一重要的事情。梦中出现的人物越多，你醒来时就会更加高兴。它是一种梦中人愈多愈高兴的情况。"梦中如果你孤身一人，你的感觉就不会很好，"克莱默解释说，"你可以把这一点与人们睡醒时的心理联系起来，在刚睡醒的状态下孤单一人只会导致较多的不快。这是因为与人交际才能令人高兴。"

一些研究人员已经探讨了情绪和行为的关系，医生们也深入研究了这种关系。而且他们已经发现了一些有趣的相互关系。

克莱默说："我们发现，人越友好、越有锐气、思维越清晰，也就越一困倦，令人惊奇的是，你越不高兴，但是活儿却干得越好。最后这种情况不高兴--我解释不了。"而且一个人情绪水平和他行为水平在一天中的上下波动总是一致的。

最初，退伍军人管理医院的研究只对男人进行了研究，因为男人的梦研究起来容易得多。男人的梦和女人的梦是不同的。的确，在解释梦中出现的人物、他们的活动、活动地点和他们的感觉差异时，性别是最重要的因素。克莱默医生说："但你对比男人和女人时，你会发现他们梦的内容有很大的不同，这种不同与你比较，比如20岁和60岁的人或者黑人和白人要大得多。"

去年，退伍军人管理医院的研究者开始研究妇女的睡眠、做梦和情绪的关系。这项工作正在继续进行，但是一开始的发现有力地证实了他们在对男人研究时的发现。

"总的来说，男人和女人几乎没有什么两样，"克莱默说。