Then the door closes behind us and a few hours later even those fragmentary memories we had when we woke have been wiped away.
That is how it feels. You wake up and still have access to bits of the dream. But as you try to bring the dream more clearly to mind, you notice that even those few fragments are already starting to fade. Sometimes there is even less. On waking you are unable to shake off the impression that you have been dreaming; the mood of the dream is still there, but you no longer know what it was about. Sometimes you are unable to remember anything at all in the morning, not a dream, not a feeling, but later in the day you experience something that causes a fragment of the apparently forgotten dream to pop into your mind. No matter what we may see as we look back through the doorway, most of our dreams slip away and the obvious question is: why? Why is it so hard to hold on to dreams? Why do we have such a poor memory for them?
In 1893, American psychologist Mary Calkins published her ‘Statistics of Dreams’, a numerical analysis of what she and her husband dreamed about over a period of roughly six weeks. They both kept candles, matches, pencil and paper in readiness on the bedside table. But dreams are so fleeting, Calkins wrote, that even reaching out for matches was enough to make them disappear. Still with an arm outstretched, she was forced to conclude that the dream had gone. She would sink back ‘with the tantalizing consciousness of having lived through an interesting dream-experience of which one has not the faintest memory.’ Even the most vivid of dreams dissolved into thin air:
To delay until morning the record of a dream, so vivid that one feels sure of remembering it, is usually a fatal error. During the progress of the observations, the account of one dream, apparently of peculiar significance, was written out in the dark by the experimenter, who then sank off to sleep with the peaceful consciousness of a scientific duty well done. In the morning the discovery was made that an unsharpened pencil had been used, and the experimenter was left with a blank sheet of paper and no remotest memory of the dream, so carefully recalled after dreaming it.
That arm reaching for the matches and falling back says it all.
A few preliminary remarks. Research into dreams is a methodological nightmare, if you will forgive the irresistible metaphor. One of the problems is that the results of research into dreams vary according to the methods used. In the time when rapid eye movements were taken to be evidence of dreaming, it seemed you might as well carry out experiments using animals, as long as they exhibited rapid eye movement (REM) sleep. A series of experiments was done to test the theory that preventing an animal from dreaming would eventually have a deleterious effect on its memory. The chosen laboratory animals, rats, were placed on floating platforms. During deep sleep they lay motionless and all was well, but during REM sleep they became slightly restless and would slide off into cold water. Splash: wide awake. After a few nights without REM sleep they did indeed forget a learned task, a route through a maze, more quickly. Another experiment was designed to test the same hypothesis about REM sleep and memory, again with rats but using a different procedure. As soon as rapid eye movements occurred, the rats were carefully woken by being shaken, rather in the way that a child will wake its guinea pig. These rats had no problem at all with learning their maze task. It seemed the learning difficulties had arisen not because of the deprivation of REM sleep but as a result of the stress caused by sliding into cold water. The conditions of the experiment determined the conclusions about dreams and memory to be drawn from it.
A second complication is that we have no direct access to another person’s dreams. Personal access to our own dreams itself presents all kinds of unavoidable obstacles. All we can measure about dreams is the behavior of the dreamer, such as the eye movements made while dreaming, which provide only indirect data, as we shall see. The researcher is dependent on the dreamer’s own report and no one understands better than the dreamer that the report does not correspond precisely with the dream. Dream research is the domain of oblique measurement, derivative knowledge and hunches. We should not expect any absolute conclusions or definitive answers here. The dream researcher, just like the dreamer, explores dimly lit rooms.
Then there is the incoherence of many theories on the subject. In psychology you are almost guaranteed to encounter the most diverse and sometimes contradictory theories about one and the same phenomenon. Insights change, interests shift, some questions lose the background from which they derived their significance, but even in psychology it is rare to find such a wide range of theories as there are concerning dreams. This applies to the details, but it is no less true of some of the most general insights and attitudes. We come upon the belief that dreams provide a profound understanding unachievable by any other means right alongside a conviction that they mean nothing at all. Some psychologists are convinced dreams are absolutely essential to good mental health, others that nothing will change if a person no longer dreams, perhaps as a result of certain medication. Dreams are utterly indispensable, or a chance by-product, or anything in between. Reading about dreams and memory, I often had the feeling that I too was wandering through a dim and ancient house of shadow.
The lizard dream
The most obvious explanations as to why we forget dreams were put forward in 1874 by German philosopher Ludwig Strümpell. He suggested that dream images are too weak to penetrate the memory, just as in daytime many stimuli are too weak to leave any trace. Dream images are rarely experienced more than once, so repetition, which is generally a powerful strategy for remembering things, does not occur. It is perhaps no accident that those dreams we do remember tend to be recurring dreams. Most people simply care too little about their dreams; as soon as they wake, the tasks of the day demand their full attention and all memories of the dream evaporate. Strümpell observed that people who kept a dream diary for a while found that they dreamed more and became better at remembering their dreams, a phenomenon that has since been corroborated repeatedly. Lastly, dream images were thought too incoherent to be recorded with the help of orderly associations. They consist of unconnected images and our memories are better at dealing with a series of events that follow each other in a natural order. To use a metaphor that was not available in Strümpell’s day, dreams are like a chaotically edited film, with fragmentary scenes, so it is hardly surprising that we fail to remember the images. To Strümpell the puzzle is not so much why we forget dreams as why we occasionally remember them.
Strümpell’s explanations are old, but that does not mean they are outdated. Many modern researchers point to a lack of associative cohesion in dreams, or to poor concentration in the transitional phase between sleeping and waking. It is hard to test the validity of the argument that in a dream all kinds of things happen that are inexplicable, illogical or downright impossible and that lack of cohesion makes them hard to recall. We might just as easily arrive at the opposite conclusion. If in real life I suddenly found myself in the basement with the attractive lady next door, I would certainly remember it a week later, all the more so because our house has no basement. I know I have had dreams of that kind from time to time, but I cannot remember a single one of them. Even the sometimes decidedly peculiar content of our dreams is no guarantee that we will file them away. Moreover, the realization that there is something odd about the events of a dream usually comes later, when you relate or contemplate the dream. You then spot one incongruity after another: people who could never have met, dead people brought back to life, people who turn up out of nowhere and with whom you start chatting without first asking where they have suddenly sprung from. In dreams you may be able to speak fluent Spanish, or you meet someone in Berlin even though you were at home a moment ago. When dreaming, nothing surprises us. So how the strange nature of many dreams affects our ability to remember them remains an open question.
What makes the forgetting of dreams so puzzling is that there seem to be so many intimate connections between dream and memory. Take ‘day residues’, those fragments of the day’s events that return to us at night in our dreams. They surely suggest that dreams derive some of their material from our memories. There are even examples of dreams that seem to prove the dreamer has access to more memories than in waking life. This is an example of the phenomenon known as hypermnesia. It is as if the dreamer’s memory holds open doors that remain closed in daytime. Freud – there he is already – writes in The Interpretation of Dreams about the experience of Belgian philosopher and psychologist Joseph Delboeuf.
Delboeuf dreams he is walking across his snow-covered land when he finds two half-frozen lizards. He picks them up, warms them and puts them in a cleft in the wall. He plucks a few fronds from a fern and holds them out to the lizards. In his dream he knows the name of the fern: asplenium ruta muralis. A little later he spots another two lizards coming to eat the fronds and when he looks round he sees a whole throng of them, so many that they cover the path, all on their way to the cleft in the wall.
Delboeuf knew hardly anything about plants, but he was curious about the name he had dreamed and to his amazement it turned out to exist in reality: asplenium ruta muraria. In his dream he had merely bastardized muraria into muralis. It was a mystery to him how the name of a plant he had never heard of before could pop up in his dream.
Excerpted from «Forgetting: Myths, Perils and Compensations»