The curve of sleep depth shows that our withdrawal from reality is not sudden but gradual. The transition from wakefulness to sleep is characterized at first by blurred visions, colours, shapes, moving objects with a scarcely defined outline, and immediately after by curiously symbolical visions, known as hypnogogic visions.

Those phenomena are difficult to study for they are forgotten by the end of the night. The observer has to train himself to wake up after a few minutes of unconsciousness, a result which is achieved without difficulty after a few trials.

The first visions of the night are in every subject I have asked and in myself, symbolical of the passage from one state to another. One hypnogogic vision I have had many times is of wading slowly into a lake or the sea, until the water reaches to the middle of my body after which I start swimming.[2]One night when I had a little difficulty in falling asleep my hypnogogic vision represented a truckman looking like myself whipping a team of horses hitched to a big load who were crossing a very high bridge leading from the city into the open.

Another night, after seeing the “Follies,” I dreamt that the police was trying vainly to quell a disturbance and that the rioters succeeded in placing their own police in charge of the disturbance. The newcomers were attired like the front row girls of the Follies. No more symbolical picture of the whole nervous situation could be found. The day’s repressions being gradually replaced by the “follies” of dreamland.

Not only is the passage from reality into dreamland thus symbolized by appropriate representation but the mental work of reality gradually merges with the mental work of the sleeping state.

Thoughts of the day merge directly with the dream thoughts. There is no gap between waking thoughts and sleeping thoughts. This has been demonstrated by Silberer’s experiments.

“The very first dream,” Silberer says, “visualizes, dramatises and interprets the very last waking thought.”

1st Example: “I applied some boric ointment to the mucous of my nose before retiring to relieve a painful dryness.”

Dream: “I see some one offering money to some one else. Only I notice that it is my right hand which is putting money into my left hand.”

Interpretation: “I have often thought that this medication did not help my nose trouble but simply concealed it. The action is therefore presented as illusory help.”

2nd Example: “I am thinking of a dramatic scene in which a character would intimate a certain fact to another character without putting the thought into words.”

Dream: “One man is offering to another man a hot metallic cup.”

Interpretation: “The cup transmits an impression of heat which has not to be expressed through spoken words.”

3rd Example: “I try to remember something which in my sleepy state eludes me.”

Dream: “I apply for information to a grouchy clerk who refuses to impart it to me. The interpretation is obvious.”

4th Example: “I think that many simple arguments could be brought forth to prove some thesis of mine.”

Dream: “A drove of white horses moves downward through my field of vision. Interpretation obvious.”

Likewise sleeping thoughts gradually merge with waking thoughts in the moments preceding awakening.

The last dreams of the night or hypnopompic visions generally dramatize our awakening in picturesque, symbolical fashion.

Here are several examples collected by Silberer from observations on himself:

“I return to my home with a party of people, take leave of them at the door and enter.”

“After visiting some place, I drive home along the same road which lead me there.”

“One morning I woke up and decided to doze off for another half hour: I dreamt then that I was locked up in a house and I woke up saying: ‘I must have the lock broken open.’”

In hypnopompic visions we generally enter a house, a forest, a dark valley or take a train or a boat, or we fall (see typical dreams).