Dream carry-over effects can be invitations to dialogue with the unconscious.
An often overlooked finding of modern dream research is that dreams are generally forgotten. The human brain cycles through four or five phases of rapid eye movement (REM) sleep during an average night’s slumber, and if REM sleep is a reliable trigger of dreaming, that means everyone is forgetting nearly all the dreams that pass through their minds each night. Not remembering most of our dreams seems to be a normal, natural feature of psychological functioning.
Why, then, do we remember any dreams at all? Part of the answer is that some dreams are simply impossible to forget. Setting aside personal interest, cultural influence, and other external factors, there seems to be an innate tendency within all people to experience highly intensified dreams that make a strong impact on waking awareness. Such dreams may be rare, and their impact may diminish over time, but they clearly demonstrate that some of the dreams that cross the memory threshold do so because of their vivid experiential qualities, what I and other researchers call carry-over effects.
Varieties of Carry-Over Effects
Carry-over effects are feelings, sensations, and bodily responses from dreaming that are still experienced even after awakening. It’s like a part of the dream world manages to seep into the waking world. Different kinds of dreams have different kinds of carry-over effects. For example, an intense nightmare of being chased by a frightening stranger can have the carry-over effects of awakening in a full-body sweat, muscles trembling, with increased respiration and heart rate. Alternatively, a dream of a pleasant romantic encounter can lead to carry-over effects of strong genital arousal, occasionally leading to climax. Vivid dreams of flying and falling can both generate extremely realistic carry-over effects involving visceral sensations of gravity.
This variety of carry-over effects shows that dreaming is not just a complex mental process, but a complex bodily process, too. Many different physiological systems can be activated during REM sleep and dreaming, but instead of being directed outward, as they are in the waking state, these systems are directed inward, toward the creation of the imaginal world of the dream.
Possible Meanings of Carry-Over Effects
Perhaps carry-over effects are merely glitches of the sleeping brain, the accidental side-effects of a random surge of energy during REM sleep, like a cup that spills when filled with too much water. That is possible, but at least two other explanations suggest a more adaptive value for dreams with these highly memorable qualities.
First is that the wide variety of mental and physical systems stimulated in these dreams is itself the point. In our usual waking lives, we draw upon and actualize a mere fraction of our human potentials. To prevent the atrophy of those unused abilities and to keep them in a condition of functional readiness, dreams create highly lifelike scenarios in which those latent capacities may be expressed, exercised, and developed. From an evolutionary perspective, this attribute of dreaming contributes to our adaptive flexibility and readiness to act effectively in survival-related situations we have never encountered in waking life. A simple analogy would be running a car engine for an hour a day during a cold winter. The car isn’t actually going anywhere, but running the engine now will make it possible to drive the car in the future when the weather conditions change.
A more therapeutically-focused explanation for dreams with carry-over effects is that they represent special calls for attention from the unconscious. They are signals of psychological importance and invitations to a dialogue with your dreaming self. With some dreams, the invitations may shade more into demands—you will pay attention to this, you will not forget it.
A helpful approach to the interpretation of dreams with carry-over effects starts with a focus on the emotional continuities between dreaming and waking. To discern the meanings of these dreams, a good question to ask is where else these same feelings can be found in current waking life, whether in a relationship or a work project or a health-related issue. Whatever the situation may be, the dream is doing everything possible to highlight its emotional importance and make it a priority for waking awareness.
Carry-over effects pose an intriguing oneiric paradox: the dream is not real, but it has real effects on our bodies and emotions in the waking world. The scary monster chasing you isn’t real, but your beating heart and feelings of terror when you wake up are real. This paradox can quite naturally stimulate people’s curiosity about religious and spiritual questions regarding identity, perception, and the nature of reality. It seems the universal experience of highly memorable dreams with vivid carry-over effects, occurring in cultures all over the world and throughout history, has in this way played an impactful role not only in the individual lives of the dreamers but also in the broader growth of religious and spiritual systems of belief.