Dreaming: a psychological view

Abstract

Dreaming has fascinated mankind since the dawn of history. This article focuses on the psychologically oriented research which has three major areas of interest: (1) a description of dreams (What do dreams look like?), (2) factors influencing dream content and (3) the effects of dreams on subsequent waking life. The following definition attempts to cover the consensus of the researchers in the field: dream or dream report is the recollection of mental activity which has occurred during A more detailed differentiation between different types of dreams is based on the underlying physiology, e.g. REM dreams, NREM dreams and sleep-onset dreams or content characteristics such as nightmares and lucid dreaming. Next, methodological issues that form the basis of modern dream research like the process of dream recall, methods of collecting dream reports and dream-content analysis, are discussed. Especially for the basic method of psychological dream research, dream-content analysis, reliability and validity issues are addressed in order to allow a proper interpretation of findings in this area. Whereas there are large numbers of studies on the so-called continuity hypothesis (which postulates that dreams are reflecting waking-life experiences), the hypothesis itself remains very imprecise. In order to stimulate future research, a mathematical model describing factors which affect the incorporation rate of waking-life experiences into dreams is presented. These are exponential decrease with time, emotional involvement, type of waking-life experience, interaction between personality traits and incorporation of waking-life events and time of the night (time interval between sleep onset and dream onset). Some of these factors are already supported by studies investigating the effect of pre-sleep experiences, real stress and trauma on dreams. The research investigating the effects of dreams on subsequent waking life is rather scarce. Most often, participants report that dreams affect their daytime mood, especially negatively toned dreams such as nightmares. Therefore, the imagery rehearsal therapy, an easily applicable tool for treating nightmares, is also briefly outlined. Anecdotal evidence and several surveys indicate that dreams stimulate daytime creativity in artists, scientists and normal samples. Future research will focus on specific models describing the continuity between waking and dreaming, the correspondence between physiological parameters during sleep and dream content and the effect of dreams on waking life. The aim of this kind of paradigm is to approach the question whether dreaming serves a function or works independently from the functions of sleep, especially those formulated for REM sleep.