If you've found yourself dreaming about tidal waves, you may have recently experienced some sort of stress or trauma. The image of tidal waves has frequently been reported in clinical and anecdotal studies of dreams, usually after the dreamer had suffered a traumatic experience such as a fire, assault or rape.
But the trauma need not have happened to you or anyone you know for the image to appear in your dreams. According to one Tufts researcher's study, tidal wave images have appeared more frequently in the general population's dreams since Sept. 11, 2001.
Ernest Hartmann, professor of psychiatry at the Tufts School of Medicine, said that every single American suffered some degree of trauma six years ago following the Sept. 11 terrorist attacks. His paper, "A Systematic Change in Dreams After 9/11/01," featured in the February issue of the journal SLEEP, illustrates how intensified images in Americans' dreams after Sept. 11 have reflected a nationwide traumatic experience.
After Sept. 11, "all our dreams changed," Hartmann said. Hartmann has used this change to support his theory, known as the Contemporary Theory of Dreaming.
Hartmann drew his conclusions from an experiment in which 11 men and 33 women, ages 22 to 70 and living throughout the United States, submitted the last 10 dreams they had before and the first 10 dreams after Sept. 11. The participants, who had been recording their dreams for at least two years, did not live in Manhattan and had no relatives or close friends who died in the attacks.
"The main point is that these people are pretty representative [of the average American]," Hartmann said.
A judge with no knowledge of the study's nature then evaluated each submitted dream. According to the evaluations, dreams after Sept. 11 were not longer or more vivid than they had been, and they did not feature more images of skyscrapers or planes. What did increase was the occurrence and intensity of the dreams' "central images."
The idea of a "central image" in dreams is the key to Hartmann's theory. According to the theory, thoughts that are kept separate while awake become connected during dreams. These connections are guided by the dreamer's emotions, but those emotions usually aren't manifested explicitly; instead they are represented in the dream's central image. Even when a dreamer doesn't remember an emotion, they do remember an intense, overriding image.
The tidal wave, representing terror or anxiety, provides a good example of a central image because it is "so obviously not about a real event," Hartmann said. He explained that, according to his theory, the central image represents the dreamer's emotions while the image's intensity indicates the power of that emotion. Dreams described as "important" or "memorable" have more intense central images than unimportant dreams.
In the experiment, the occurrence and intensity of the central image increased significantly in dreams after Sept. 11 - the same as the increase seen in dreams occurring after a more personal traumatic experience.
As far as the specific emotions behind the central images, judges observed an increase in feelings of being attacked or the fear of attack.
Hartmann's experiment is unique in that it attempted to observe the dreams of an entire nation that suffered trauma, rather than individual traumatic experiences.
Freshman Fred Seddon had a more direct experience with the World Trade Center attacks. He was at school in Manhattan when the attacks occurred and was sent home to watch on TV the chaos happening just outside his window.
"I guess my dreams were scarier from that point on, but I was more affected by New Yorkers' positive attitudes than the event itself," Seddon said.
Though six years later Seddon cannot remember any specific dream reflecting the shock of Sept. 11, Hartmann's study indicates that, along with the rest of the nation, Seddon's dreams were probably more intense.
In his paper, Hartmann said that "dream images are new creations, guided by emotion, not replays of waking experiences." This, he said, explains why the post-Sept. 11 increase in central images and their intensity did not involve an increase in images of planes, skyscrapers or towers. The emotions Americans felt after the attacks could have been represented by any number of central images, including the classic tidal wave, he said.
But images of the World Trade Center attacks, repeatedly seen on television and in newspapers, have now been added to the collection of central images representing personal emotional stress. These images appear to have been stored in Americans' brains as symbols of anxiety and would likely occur in a dream following a traumatic experience, just like the tidal wave.
Hartmann is still working with the data from the study. His current focus is "big dreams" - the dreams we remember for years afterwards. Such dreams are memorable, Hartmann said, "not because of an interesting, complex plot, but because of a powerful image."
