Pre-sleep and post-sleep mood as a complementary evaluation of emotionally impactful dreams
Impactful dreams are reported by the dreamer to have an effect on their waking mood. However, the time course relationship of negative and positive impactful dreams with pre-sleep and post-sleep mood has not been examined closely. A total of 32 participants (21 females) reported one dream self-rated as either very or extremely emotionally impactful and one dream self-rated as not at all emotionally impactful (mundane dream), totalling 64 dreams. Participants completed a dream diary as well as pre-sleep, dream, and post-sleep mood checklists. They also completed rating scales of the impact of their dreams. The Hall & Van de Castle method was used for dream coding and analysis. A dream containing more positive than negative emotions was classified as positively impactful and vice versa. The 2 x 3 analysis of variance demonstrated a significant difference between mundane dreams and both negative and positive impactful dreams. Overall, negative impactful dreams were associated with higher negative mood levels at pre-sleep, in dream, and at post-sleep, compared to mundane dreams. Conversely, positive impactful dreams were associated with more positive mood levels during the dream and at post-sleep, but not at pre-sleep. Correlational analyses demonstrated that in negative impactful dreams, negative dream mood strongly correlated with negative post-sleep mood. Similarly, in positive impactful dreams, positive dream mood strongly correlated with positive post-sleep mood. However, pre-sleep and dream mood, whether positive or negative, did not significantly correlate. Additionally, there was a significant correlation between pre-sleep and post-sleep positive mood in positive impactful dreams and mundane dreams. These results confirm that dream mood and post-sleep mood are positively related, further suggesting a potential effect on post-sleep mood. The absence of a relationship between pre-sleep and dream mood undermines the continuity theory as well as modern dream function theories for emotions. The threat simulation theory is also used to interpret results.