Dreaming and Insomnia: Link between Physiological REM Parameters and Mentation Characteristics

Abstract

(1) Background: An unresolved phenomenon of insomnia disorder is a discrepancy between objectively measured sleep and subjective complaints. It has been shown that rapid eye movement (REM) sleep might be especially vulnerable to an altered perception. The present work aimed to investigate the link between physiological REM parameters and mentation characteristics in REM sleep. (2) Methods: 22 patients with insomnia and 23 good sleepers indicating at least one REM mentation within an awakening study were included. Multivariate analyses of variance (MANOVAs) were calculated to examine group differences and effects of mentation characteristics on number of arousals, REM density, and spectral power prior to awakenings. (3) Results: Increased perceived wakefulness was related to lower delta, theta, and alpha power in the minute prior to the REM awakenings. Nevertheless, no group differences regarding spectral power were found. With respect to number of arousals and REM density, no significant effects of mentation characteristics and no group differences were found. (4) Conclusions: Our results suggest that spectral power in REM sleep is linked with altered sleep perception. Reduced delta, theta, and alpha power might be a signature of this modified REM sleep associated with a high level of perceived wakefulness. Future awakening studies are necessary to further explore the link between physiological REM parameters and sleep perception.

How many hours do you sleep? A comparison of subjective and objective sleep duration measures in a sample of insomnia patients and good sleepers

“…This perceived wakefulness was linked to spectral power in REM sleep, i.e. lower delta, theta and alpha power in the minute prior to the REM awakenings (Benz et al, 2020). Furthermore, another one of our studies investigating ERPs caused by auditory stimulation found reduced P2 amplitudes (Feige et al, 2021).…”

“…Rapid eye movement (REM) sleep, as the most aroused sleep state, is altered in insomnia and thus might be especially vulnerable to an altered sleep perception (Feige et al, 2018; Riemann et al, 2012). Other studies from our laboratory identified a number of potential physiological parameters (increased arousal densities, spectral power, reduced P2 amplitudes) that may contribute to the subjective experience of non‐restorative sleep or perceived wakefulness during this sleep state (Benz et al, 2020; Feige et al, 2008, 2018, 2021). While this and other research contributed to our understanding of sleep (mis)perception in insomnia, the phenomenon still remains enigmatic as the primary cause of these changes is not known.…”

Proteomics Reveals Molecular Changes in Insomnia Patients with More Dreams

“…Interestingly, it was shown that elevation of negative content in dreams is associated with reduced sleep efficiency in insomnia patients [38]. Since rapid eye movement sleep is of great significance to the subjective experience of insomnia, alteration of consciousness is prone [39]. Therefore, investigation of protein expression in patients with the dream in insomnia may provide a better understanding of the pathophysiology of insomnia.…”

On the relationship between EEG spectral analysis and pre‐sleep cognitive arousal in insomnia disorder: towards an integrated model of cognitive and cortical arousal

“…This was empirically supported by a study investigating event‐related potentials during auditory stimulation, which found reduced P2 amplitudes during phasic REM sleep and a correlation between this reduction and the extent of sleep misperception (Feige et al, 2021). Furthermore, Benz et al (2020) were able to demonstrate a significant association between the perception of consolidated REM sleep as being awake and a decrease in delta, theta, and alpha power. This was interpreted as indicative of cortical arousal (Benz et al, 2020).…”