Dreams help us to integrate emotional experiences from the day, they occur without our conscious awareness but they actually have an important impact over our emotional state during the day, our dreams help us figure out what memory means.
Studies have shown that most emotions in our dreams are negative, and that we face more fears in our dreams than in our day (when we’re awake). These negative emotions add up to about more than half of all emotions experienced in our dreams. Some of these emotions are apprehension, stress, sadness, anger, confusion, anxiety, helplessness, and guilt.
We can say that during REM sleep, when we have the most vivid dreams, information related to our fears and survival is processed.
In more recent studies it was found that the area of the brain that concentrates most of our emotional memory, the limbic system, is more active when we sleep in REM than when we are awake, as are the connections known to be related to our fight-or-flight reactions. Not only that, the areas that are more active in our logical thinking have minimum activity as we dream. This brain activity suggests that our dreams are guided by our feelings, not our logic, and constructed with the new and old memories related to our prevalent recent worries.
Studies by Rosalind Cartwright show that the first REM period dreams are the ones charged with the most negative emotions of the night, while the successive REM period dreams become progressively more positive and they recall earlier life memories that are incorporated to our dreams, memories from our childhood or earlier in life that are charged with similar emotional content to the current information that is being processed. The fact that REM periods increase in duration as the night progresses indicates that REM sleep works as a mood regulator, making us wake up happier.
This doesn’t happen in people who are depressed who start with negative emotional dreams that progress to highly negative charged dreams through the night, becoming even more negative in the morning.