Sleep Onset Process as an Altered State of Consciousness

Cvetković, Dean; Ćosić, Irena

doi:10.1007/978-3-642-18047-7_7

Cited by 6 publications

(4 citation statements)

References 72 publications

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“…NREM2 occupies about half of our sleeping time. Although, loss of consciousness can be variously documented at NREM1 (Ogilvie, 2001 ) the definitive start of sleep is practically marked by the first appearance of the hallmarks of NREM2 (Cvetkovic and Cosic, 2011 ), spindles and K-complexes (KCs). A spindle is a brief 11–16 Hz oscillation (De Gennaro and Ferrara, 2003 ), while a KC consists mainly of a prominent negative wave, the largest waveform of healthy EEG (Cash et al, 2009 ).…”

Section: Introductionmentioning

confidence: 99%

Using MEG to Understand the Progression of Light Sleep and the Emergence and Functional Roles of Spindles and K-Complexes

Ioannides¹,

Liu²,

Poghosyan

et al. 2017

Front. Hum. Neurosci.

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We used tomographic analysis of MEG signals to characterize regional spectral changes in the brain at sleep onset and during light sleep. We identified two key processes that may causally link to loss of consciousness during the quiet or “core” periods of NREM1. First, active inhibition in the frontal lobe leads to delta and theta spectral power increases. Second, activation suppression leads to sharp drop of spectral power in alpha and higher frequencies in posterior parietal cortex. During NREM2 core periods, the changes identified in NREM1 become more widespread, but focal increases also emerge in alpha and low sigma band power in frontal midline cortical structures, suggesting reemergence of some monitoring of internal and external environment. Just before spindles and K-complexes (KCs), the hallmarks of NREM2, we identified focal spectral power changes in pre-frontal cortex, mid cingulate, and areas involved in environmental and internal monitoring, i.e., the rostral and sub-genual anterior cingulate. During both spindles and KCs, alpha and low sigma bands increases. Spindles emerge after further active inhibition (increase in delta power) of the frontal areas responsible for environmental monitoring, while in posterior parietal cortex, power increases in low and high sigma bands. KCs are correlated with increase in alpha power in the monitoring areas. These specific regional changes suggest strong and varied vigilance changes for KCs, but vigilance suppression and sharpening of cognitive processing for spindles. This is consistent with processes designed to ensure accurate and uncorrupted memory consolidation. The changes during KCs suggest a sentinel role: evaluation of the salience of provoking events to decide whether to increase processing and possibly wake up, or to actively inhibit further processing of intruding influences. The regional spectral patterns of NREM1, NREM2, and their dynamic changes just before spindles and KCs reveal an edge effect facilitating the emergence of spindles and KCs and defining the precise loci where they might emerge. In the time domain, the spindles are seen in widespread areas of the cortex just as reported from analysis of intracranial data, consistent with the emerging consensus of a differential topography that depends on the kind of memory stored.

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Section: Introductionmentioning

confidence: 99%

Using MEG to Understand the Progression of Light Sleep and the Emergence and Functional Roles of Spindles and K-Complexes

Ioannides¹,

Liu²,

Poghosyan

et al. 2017

Front. Hum. Neurosci.

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“…Hence, the arousal index is the average number of arousals per hour. [ 39 ] Number of awakening is a number of transitions from sleep to wakefulness, lasting more than 15 s. Wake index identified as the number of awakening events per hour of sleep. [ 40 41 ] SpO 2 is peripheral capillary oxygen saturation.…”

Section: Methodsmentioning

confidence: 99%

Hypothalamic–pituitary–gonadal activity in paradoxical and psychophysiological insomnia

et al. 2019

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Background:Although insomnia is a sex-dimorphic disorder, there is limited knowledge about the association between sex hormones and insomnia. In the present study, the level of hypothalamus–pituitary–gonadal (HPG) axis activity was investigated in patients with insomnia by measuring serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), 17α-Hydroxyprogesterone, testosterone, progesterone, estradiol, dehydroepiandrosterone sulfate, and sex hormone-binding globulin.Methods:Numbers of 19 patients; including 13 females (68.40%) with paradox insomnia (32–53 years; 43.20 ± 6.40) and 17 patients; including 8 females (47.05%) with psychophysiological insomnia (14–62 years; 38.40 ± 16.30) were recruited. Seventeen aged-matched normal sleeper consisted of 13 males (26–59 years; 40.70 ± 10) consisted of 13 males (76.50%) were also recruited as control group. Insomnia was diagnosed by a sleep clinician according to the International Classification of Sleep Disorders-Second Edition criteria and an overnight polysomnography (PSG). A volume of 5 ml of venous blood samples were collected, prepared, and stored at 8 AM under standard condition. Serum levels of hormones were measured using enzyme-linked immunosorbent assay kits. Data were analyzed by Chi-square and ANCOVA. The associations between PSG and biochemical parameters were evaluated using multiple linear regression analysis.Results:There were no significant differences in all biochemical analyses between two insomnia subgroups (paradoxical and psychophysiological insomnia) and normal sleepers. Testosterone was positively related to maximum pulse transit time (PTT). Moreover, both LH and FSH were positively related to wake index and diastolic blood pressure.Conclusion:Although there were no significant differences in all HPG's hormones between groups, both LH and FSH were associated with wake index and diastolic blood pressure. Moreover, testosterone was positively related to PTT.

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“…A number of phenomenological and neurobiological features appear common across diverse induction methods such as hypnosis, sensory deprivation, trance, meditation, and psychedelic drugs [8]. These include fragmentation and sometimes loss of a sense of selfhood, changes in the experience of space and time, novel perspectives and the perception of novelty, cognitive changes, perceptual distortion, and emotional lability [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Producing Altered States of Consciousness, Reducing Substance Misuse: A Review of Psychedelic-Assisted Psychotherapy, Transcendental Meditation and Hypnotherapy

Sekula,

Puspanathan,

Downey

et al. 2024

Psychoactives

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A set of interventions that can produce altered states of consciousness (ASC) have shown utility in the treatment of substance misuse. In this review, we examine addiction-related outcomes associated with three common interventions that produce ASCs: psychedelic-assisted psychotherapy (PP), Transcendental Meditation (TM) and hypnotherapy (HT). While procedurally distinct, all three interventions are associated with some common phenomenological, psychological, and neurobiological features, indicating some possible convergent mechanisms of action. Along with addiction and mental health outcomes, these common features are reviewed, and their impact on substance misuse is discussed. While our review highlights some mixed findings and methodological issues, results indicate that PP and TM are associated with significant improvements in substance misuse, alongside improvements in emotional, cognitive and social functioning, behavior-change motivation, sense of self-identity, and meaning. In contrast, and despite its broader acceptance, HT has been associated with mixed and minimal results with respect to substance misuse treatment. Authors identify key research gaps in the role of ASC interventions in addiction and outline a set of promising future research directions.

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Sleep Onset Process as an Altered State of Consciousness

Cited by 6 publications

References 72 publications

Using MEG to Understand the Progression of Light Sleep and the Emergence and Functional Roles of Spindles and K-Complexes

Using MEG to Understand the Progression of Light Sleep and the Emergence and Functional Roles of Spindles and K-Complexes

Hypothalamic–pituitary–gonadal activity in paradoxical and psychophysiological insomnia

Producing Altered States of Consciousness, Reducing Substance Misuse: A Review of Psychedelic-Assisted Psychotherapy, Transcendental Meditation and Hypnotherapy

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