The kaleidoscope of bizarreness: The analysis of first-person-reports shows the relationship between dreaming and mind wandering to be complex

Unusual features of dream experience, referred to as bizarreness, are at the heart of theoretical debates about the relationship between dreaming and waking experiences. Prominent dream theories consider bizarreness as a distinctive and pervasive feature of dreaming. Others foreground the continuity between dreaming and waking consciousness, claiming that a majority of dreams are realistic and wake-like. Bizarreness has also been proposed as a dimension along which dreaming is an intensified form of waking mind wandering. While increasing research is focusing on the systematic comparison between dreaming and waking mind wandering, including bizarreness, this has largely been done through questionnaires and global ratings. Here, we present the first systematic investigation of bizarreness in dream and mind wandering reports using fine-grained content analysis. To do so, we adapted and expanded the most comprehensive existing dream bizarreness scale (The Content Analysis of Bizarreness Scale) and applied it, for the first time, to first-person reports of both dreaming and waking mind wandering. The content of 380 dreaming and mind wandering reports was analyzed by differentiating individual content elements (such as Self, Locations, Events) and types and subtypes of bizarreness. This fine-grained analysis revealed that bizarreness is not unique to dreaming, and different types and subtypes characterize waking mind wandering to varying degrees. Moreover, there is no simple quantitative difference such that dreaming is more bizarre than mind wandering along all contents or bizarreness types and subtypes. We conclude that bizarreness is kaleidoscopic: How it applies to dreaming as compared to mind wandering depends on the precise rating and level of measure used. While dreaming and mind wandering are similarly bizarre in some respects, in others, each has their own distinctive bizarreness profile. We propose that our findings can inform and guide future work not just on bizarreness in dreams and mind wandering, but also more broadly on the relationship between conscious experience in sleep and wakefulness.