Dream recall, white dreaming, and sleep duration: A diary study in patients with sleep disorders

Every human dreams; however, individuals differ in terms of how often they can remember some kind of dream experience. This study investigates the relationship between sleep duration and dream recall, including the phenomenon of “white dreaming.”

A sample comprising 1080 patients with sleep disorders (age 44.77 ± 17.12 years) and 6530 nights was included. Using sleep diaries, it was explored whether intraindividual changes and/or interindividual differences in sleep duration impact the different levels of dream recall (no dream recall, the feeling of having dreamed, and dream recall with explicitly remembered dream content).

The results revealed that both intraindividual changes and interindividual differences in sleep duration exhibit a significant positive correlation with dream recall in general. Detailed analyses showed that white dreaming and dream recall with explicitly remembered dream content are influenced by different factors.

Considering these results, the integrative model of dream recall by Schredl [12] needs to be expanded. Future studies could use imaging techniques to investigate whether the differences between the various levels of dream recall can be explained by different brain mechanisms.