Predictive coding, multisensory integration, and attentional control: A multicomponent framework for lucid dreaming

Abstract

Lucid dreaming (LD) is a mental state in which we realize not being awake but are dreaming while asleep. It often involves vivid, perceptually intense dream images as well as peculiar kinesthetic sensations, such as flying, levitating, or out-of-body experiences. LD is in the cross-spotlight of cognitive neuroscience and sleep research as a particular case to study consciousness, cognition, and the neural background of dream experiences. Here, we present a multicomponent framework for the study and understanding of neurocognitive mechanisms and phenomenological aspects of LD. We propose that LD is associated with prediction error signals arising during sleep and occurring at higher or lower levels of the processing hierarchy. Prediction errors are resolved by generating a superordinate self-model able to integrate ambiguous stimuli arriving from sensory periphery and higher-order cortical regions. While multisensory integration enables lucidity maintenance and contributes to peculiar kinesthetic experiences, attentional control facilitates multisensory integration by dynamically regulating the balance between the influence of top-down mental models and the precision weighting of bottom-up sensory inputs. Our novel framework aims to link neural correlates of LD with current concepts of sleep and arousal regulation and provide testable predictions on interindividual differences in LD as well as neurocognitive mechanisms inducing lucid dreams.

The functions of sleep: A cognitive neuroscience perspective

“…Simor et al. ( 42 ) provide a novel multicomponent neurocognitive framework for the onset and maintenance of what is known as lucid dreaming. They extend and build upon prior theories of dreaming suggesting that lucid dreaming is induced when top-down models of the self clash with bottom-up interoceptive pathways, generating prediction errors.…”

Electrophysiological correlates of lucid dreaming

“…Also note that dSPM’s noise normalization approach provides more focal source clusters, revealing the temporo-parietal junction (TPJ) in the right hemisphere as a likely origin of beta activity. The TPJ has been hypothesized to be a key structure according to a recent theoretical framework of LD (76) since it integrates visual, auditory, tactile, proprioceptive, and vestibular information, contributing to self-consciousness and internal body imagery (78). Disrupting TPJ activity during the waking state with magnetic (79) or electric (80) transcranial stimulation can cause an out-of-body experience, defined as a subjective sensation of being “outside the own body” (81).…”

“…Gamma1 activity increases were localized primarily to left-hemispheric temporal areas and may accompany processes of verbal insight (75). Furthermore, increased activity within the middle temporal gyrus during LD has been hypothesized within a framework of predictive coding and resolution of low-level sensory prediction errors (76).…”

Fractal cycles of sleep: a new aperiodic activity-based definition of sleep cycles

“…In view of this literature, we speculate that fractal fluctuations may reflect two antagonistic roles of sleep (Simor et al, 2022). Specifically, fractal cycle troughs might cohere with sensory disconnection that facilitates restorative properties of sleep while fractal cycle peaks reflect monitoring of the environment that transiently restores alertness (Table 4).…”