Findings published in the December Journal of Sleep Research show that there may be an advantage to dreams that occur for up to a week after a memorable emotional event.
A study conducted by the University of Alberta and the University of Montreal of 470 psychology students revealed that not only do remembered events influence dreams on the following night; they also colour dreams that occur six to seven days later.
And, compared to dreams on the night immediately after the remembered event, the 'delayed incorporations' more often reflected interpersonal interactions, problem resolution and positive emotions, suggesting that these delayed incorporations help the person work through personal difficulties.
"This suggests an ongoing effort to resolve a problem in dreams during the week following the emergence of that problem. The dreams themselves are a kind of treatment," said Dr. Don Kuiken, a psychology professor at the University of Alberta. "Something is going on there that at least touches on and alters the resolutions that people come up with," Dr. Kuiken said.
The students were asked to recall dreams at home for one week, then to select their most recent dream and to recall events related to it from one to seven days prior to the dream. They then rated the extent of correspondence between the events and the dreams. The researchers, in turn, evaluated whether the dreams that incorporated those events reflected problem-solving activity.