A Meaningful Step Toward Understanding the Cause and Impact of Nightmares

Source: JCSM – A Meaningful Step Toward Understanding the Cause and Impact of Nightmares

Commentary on:

Nightmare Severity Is Inversely Related to Frontal Brain Activity During Waking State Picture Viewing.

Marquis LP, Julien SH, Baril AA, Blanchette-Carrière C, Paquette T, Carr M, Soucy JP, Montplaisir J, Nielsen T.

J Clin Sleep Med. 2019 Feb 4. pii: jc-18-00539. [Epub ahead of print]


Carr & Nielsen (2017): A new model of the nightmare-prone personality

A novel Differential Susceptibility framework for the study of nightmares: Evidence for trait sensory processing sensitivity

Michelle Carr  & Tore Nielsen

PDF: https://doi.org/10.1016/j.cpr.2017.10.002


Research on nightmares has largely focused on the nightmare itself and its associated negative consequences, framing nightmare sufferers as victims of a diathesis-stress induced form of psychopathology. However, there is evidence that frequent nightmare recallers are sensitive to a wide range of sensory and emotional experiences, and report vivid, bizarre and even intensely positive dream and daydream experiences. We propose sensory processing sensitivity as a novel trait marker that underlies the unique symptoms and imaginative richness found in nightmare-prone individuals. Sensory processing sensitivity describes an increased emotional reactivity, greater depth of processing, and subtle awareness of environmental stimuli—it is a ‘for better and for worse’ trait that is associated with positive outcomes in conditions of support, but also confers a tendency to be easily overwhelmed by stressors and adversity. This novel approach places nightmare-prone individuals within the broader framework of Differential Susceptibility and raises the possibility that they may benefit especially from supportive environments—a possibility that is particularly relevant for developing future treatment approaches.

Solomonova et al (2017): Sleep-dependent consolidation of face recognition and its relationship to REM sleep duration, REM density and Stage 2 sleep spindles

Source: Sleep-dependent consolidation of face recognition and its relationship to REM sleep duration, REM density and Stage 2 sleep spindles

Face recognition is a highly specialized capability that has implicit and
explicit memory components. Studies show that learning tasks with facial
components are dependent on rapid eye movement and non-rapid eye
movement sleep features, including rapid eye movement sleep density
and fast sleep spindles. This study aimed to investigate the relationship
between sleep-dependent consolidation of memory for faces and partial
rapid eye movement sleep deprivation, rapid eye movement density, and
fast and slow non-rapid eye movement sleep spindles. Fourteen healthy
participants spent 1 night each in the laboratory. Prior to bed they
completed a virtual reality task in which they interacted with computergenerated
characters. Half of the participants (REMD group) underwent
a partial rapid eye movement sleep deprivation protocol and half (CTL
group) had a normal amount of rapid eye movement sleep. Upon
awakening, they completed a face recognition task that contained a
mixture of previously encountered faces from the task and new faces.
Rapid eye movement density and fast and slow sleep spindles were
detected using in-house software. The REMD group performed worse
than the CTL group on the face recognition task; however, rapid eye
movement duration and rapid eye movement density were not related to
task performance. Fast and slow sleep spindles showed differential
relationships to task performance, with fast spindles being positively and
slow spindles negatively correlated with face recognition. The results
support the notion that rapid eye movement and non-rapid eye
movement sleep characteristics play complementary roles in face
memory consolidation. This study also raises the possibility that fast
and slow spindles contribute in opposite ways to sleep-dependent
memory consolidation.

Nielsen (2017): Microdream neurophenomenology | Neuroscience of Consciousness

Source: Microdream neurophenomenology | Neuroscience of Consciousness | Oxford Academic

PDF: Nielsen 2017 Microdreaming

Tore Nielsen*
Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Hopital du Sacre-Coeur de Montreal and Department of Psychiatry, University of Montreal, Canada

Nightly transitions into sleep are usually uneventful and transpire in the blink of an eye. But in the laboratory these transitions afford a unique view of how experience is transformed from the perceptually grounded consciousness of wakefulness to the hallucinatory simulations of dreaming. The present review considers imagery in the sleep-onset transition—“microdreams” in particular—as an alternative object of study to dreaming as traditionally studied in the sleep lab. A focus on microdream phenomenology has thus far proven fruitful in preliminary efforts to (i) develop a classification for dreaming’s core phenomenology (the “oneiragogic spectrum”), (ii) establish a structure for assessing dreaming’s multiple memory inputs (“multi-temporal memory sources”), (iii) further Silberer’s project for classifying sleep-onset images in relation to waking cognition by revealing two new imagery types (“autosensory imagery,” “exosensory imagery”), and (iv) embed a potential understanding of microdreaming processes in a larger explanatory framework (“multisensory integration approach”). Such efforts may help resolve outstanding questions about dream neurophysiology and dreaming’s role in memory consolidation during sleep but may also advance discovery in the neuroscience of consciousness more broadly.

Frontiers ebook | Sleep Spindles: Breaking the Methodological Wall

Source: Frontiers | Sleep Spindles: Breaking the Methodological Wall

PDF: OReilly et al ebook 2017

Edited by: Christian O’Reilly, Simon C. Warby, Tore Nielsen

Publisher: Frontiers Media SA

ISBN: 9782889451166

Product Name: Frontiers Research Topic Ebook

O’Reilly, Warby, Nielsen (2017)

Editorial: Sleep Spindles: Breaking the Methodological Wall, Frontiers in Human Neuroscience

pdf: oreilly-2017

Research on sleep spindles and their correlates has progressed steadily over the last decade. The subject has evolved from a simple topic of investigation to an emerging research field, as indicated this year by the first international conference on sleep spindles in Budapest, Hungary, as well as the launching of a scientific journal (i.e., Sleep Spindles and Cortical Up States: A Multidisciplinary Journal) on this topic. This increasing interest has been fueled by reports of associations of sleep spindle characteristics with diseases such as schizophrenia (Ferrarelli et al., 2007, 2010; Manoach et al.), Parkinson’s disease (Christensen et al.), REM sleep behavior disorder (Christensen et al., 2014; O’Reilly et al., 2015), Alzheimer’s disease (Montplaisir et al., 1995; Rauchs et al., 2008), autism (Limoges et al., 2005), and mental retardation (Shibagaki et al., 1982), with recovery processes following brain stroke (Gottselig et al., 2002), with cognitive faculties such as memory consolidation and intelligence (Fogel and Smith, 2011), and with sleep preservation (Landis et al., 2004; Dang-Vu et al., 2010; Schabus et al., 2012). Nonetheless, many methodological difficulties have been encountered in reliably detecting sleep spindles. Hence, this research topic was launched as a forum for proposing better practices in the study of sleep spindles and to provide new insights on spindle correlates. Authors were invited particularly to propose open-access resources that could help promote improved methods and support standardization in the field.


A total of 17 papers were accepted for publication on the research topic, with 10 being focussed particularly on methodological issues such as spindle detection and the remaining seven providing new insights on sleep spindle correlates.

Nielsen et al (2016): NREM sleep spindles are associated with dream recall

Source PDF: 2053.1.2016.003