The bizarre antics of sleepwalkers have puzzled police,perplexed scientists,and fascinated writers for centuries. There is an endless supply of stories about sleepwalkers.Persons have been said to climb on steep roofs,solve mathematical problems, compose music,walk through plate-glass windows,andcommit murder in their sleep.

How many of these stories have a basis in fact,and howmany are pure fakery?No one knows, but if some of the most sensational stories shouldbe taken with a barrel of salt, others are a matter of record.

In Revere,Massachusetts,a hundred policemencombed a waterfront neighborhood for alost boy who left his home in his sleep inandwoke up five hours later on a strange sofa in a strange living room,withnoidea how he had got there.

There is an early medical record of asomnambulist who wrote a novel in his sleep. And the great French writer Voltaire knewa sleepwalker who once got out of bed,dressed himself, made a polite bow,danced a minuet,and then undressed and went back to bed.

At the University of Iowa,astudent was reported to have the habit of getting up in the middle of the night and walking three-quarters of a mile to the Iowa River.He would take a swim and then go back to his room to bed.

The world’s champion sleepwalker was supposed to have been an Indian,Pandit Ramrakha,whowalked sixteen miles along a dangerous road without realizing that he had left hisbed.Second in line for the title is probably either a Vienna housewife or a British farmer.The woman did all her shopping on busy streets in her sleep. Thefarmer, in his sleep,visited a veterinarian miles away.

The leading expert on sleep in America claims that he has never seen a sleepwalker.He isDr. Nathaniel Kleitman, a physiologist at the Universityof Chicago.He is saidto knowmore about sleep than any other living man,and during thelastthirty-five yearshad lost a lot of sleep watching people sleep. Says he,”Of course,I know that there aresleepwalkers because I have read about them in the newspapers. But none of mysleepers ever walked,and ifI were to advertise for sleepwalkers for an experiment,I doubt that I’d get many takers.”

Sleepwalking, nevertheless,is ascientific reality. Like hypnosis,it is one of those dramatic, eerie,awe-inspiring phenomena that sometimes border on the fantastic. It lends itself to controversy and misconceptions,what is certain about sleepwalking is that it is a symptom of emotional disturbance, and that the only way to cure it is to remove the worries and anxieties that cause it.Doctors saythat somnambulism is much more common than is generally supposed. Some have estimated that there are four million somnambulists in the United States. Others set the figure even higher. Many sleepwalkers do not seek help and so are never put on record,which means that an accurate count can never be made.

The simplest explanationof sleepwalking is that it is the acting out of a vivid dream. The dream usuallycomesfrom guilt, worry, nervousness, or some other emotional conflict. The classicsleepwalker is Shakespeare’s Lady Macbeth.Her nightly wanderings were caused by herguilty consience at having committed murder.Shakespeare said of her,”The eyes are open but their sense is shut.”

Theage-oldquestion is: Is the sleepwalker actually awake or asleep? Scientists have decided that he is about half-and-half.Like Lady Macbeth,he has weighty problems onhismind,Dr,Zeida Teplitz,who made a ten-year study of the subject,says,”Some people stay awake all night worrying about their problems. The sleepwalker thrashes them out in his sleep. He is awake in the muscular area,partially asleep in thesensory area.”In other words, a person can walk in his sleep, move around,and do other things,but he does not think about what he is doing.

The second sentence in the second paragraph means that _ .