Dreams, reality and memory: confabulations in lucid dreamers implicate reality-monitoring dysfunction in dream consciousness

Introduction. Dreams might represent a window on altered states of consciousness with relevance to psychotic experiences, where reality monitoring is impaired. We examined reality monitoring in healthy, non-psychotic individuals with varying degrees of dream awareness using a task designed to assess confabulatory memory errors – a confusion regarding reality whereby information from the past feels falsely familiar and does not constrain current perception appropriately. Confabulatory errors are common following damage to the ventromedial prefrontal cortex (vmPFC). Ventromedial function has previously been implicated in dreaming and dream awareness. Methods. In a hospital research setting, physically and mentally healthy individuals with high (n = 18) and low (n = 13) self-reported dream awareness completed a computerised cognitive task that involved reality monitoring based on familiarity across a series of task runs. Results. Signal detection theory analysis revealed a more liberal acceptance bias in those with high dream awareness, consistent with the notion of overlap in the perception of dreams, imagination and reality. Conclusions. We discuss the implications of these results for models of reality monitoring and psychosis with a particular focus on the role of vmPFC in default-mode brain function, model-based reinforcement learning and the phenomenology of dreaming and waking consciousness.