Search results for "Wakefulness"

A degraded state of consciousness in healthy awake humans?

2021

Brain and Breathing

2014

Breathing is an essential feature of living organisms, and control of breathing is a very complex topic in human physiology. Breathing is differently modulated under conditions of wakefulness and sleep, and ventilation decreases during sleep in normal subjects. In patients with respiratory diseases, sleep represents a very vulnerable condition, since gas exchange usually worsens, especially in REM sleep. Several types of respiratory events can occur during sleep, and knowledge of control of breathing is essential to understand their pathophysiology. This chapter summarizes the main characteristics of ventilation during both wakefulness and sleep, the differences found between genders, and t…

Morning and evening type: The cortisol awakening response in a sleep laboratory.

2019

Abstract Background Earlier evidence indicated an association between chronotype and the cortisol awakening response (CAR). However, these earlier data were collected without objective control for participant compliance being available, which, following recent guidelines, is considered critical for ensuring data validity. Here, we are seeking to replicate these earlier findings within a well-controlled sleep laboratory set up. Methods The sample consisted of 103 young males, including 12 participants defined as ‘evening’ (MEQ   59) types. All participants slept for one night in a sleep laboratory and were wakened at 6:30 AM the next morning. Saliva samples for the assessment of the CAR were…

Information Dynamics of the Brain, Cardiovascular and Respiratory Network during Different Levels of Mental Stress

2019

In this study, an analysis of brain, cardiovascular and respiratory dynamics was conducted combining information-theoretic measures with the Network Physiology paradigm during different levels of mental stress. Starting from low invasive recordings of electroencephalographic, electrocardiographic, respiratory, and blood volume pulse signals, the dynamical activity of seven physiological systems was probed with one-second time resolution measuring the time series of the &delta

Long-term effects on cortical glutamate release induced by prenatal exposure to the cannabinoid receptor agonist (r)-(+)-[2,3-dihydro-5-methyl-3-(4-m…

2003

The aim of the present in vivo microdialysis study was to investigate whether prenatal exposure to the CB1 receptor agonist WIN55,212-2 mesylate (WIN; (R)-()-(2,3- dihydro-5-methyl-3-(4-morpholinyl-methyl)pyrrolo(1,2,3-de)- 1,4-benzoxazin-6-yl)-1-naphthalenylmethanone), at a dose of 0.5 mg/kg (s.c. from the fifth to the 20th day of gestation), that causes neither malformations nor overt signs of toxicity, influences cortical glutamate extracellular levels in adult (90- day old) rats. Dam weight gain, pregnancy length and litter size at birth were not significantly affected by prenatal treatment with WIN. Basal and K-evoked dialysate glutamate levels were lower in the cerebral cortex of adul…

Preserved somatosensory discrimination predicts consciousness recovery in unresponsive wakefulness syndrome

2017

Objective: To assess somatosensory discrimination and command following using a vibrotactile P300-based Brain-Computer Interface (BCI) in Unresponsive Wakefulness Syndrome (UWS), and investigate the predictive role of this cognitive process on the clinical outcomes.Methods: Thirteen UWS patients and six healthy controls each participated in two experimental runs in which they were instructed to count vibrotactile stimuli delivered to the left or right wrist. A BCI determined each subject's task performance based on EEG measures. All of the patients were followed up six months after the BCI assessment, and correlations analysis between accuracy rates and clinical outcome were investigated.Re…

Multi-band SWIFT enables quiet and artefact-free EEG-fMRI and awake fMRI studies in rat

2020

Functional magnetic resonance imaging (fMRI) studies in animal models provide invaluable information regarding normal and abnormal brain function, especially when combined with complementary stimulation and recording techniques. The echo planar imaging (EPI) pulse sequence is the most common choice for fMRI investigations, but it has several shortcomings. EPI is one of the loudest sequences and very prone to movement and susceptibility-induced artefacts, making it suboptimal for awake imaging. Additionally, the fast gradient-switching of EPI induces disrupting currents in simultaneous electrophysiological recordings. Therefore, we investigated whether the unique features of Multi-Band SWeep…

Trends in self-reported sleep problems, tiredness and related school performance among Finnish adolescents from 1984 to 2011

2014

The aim of this study was to investigate long-term trends in insomnia symptoms, tiredness and school performance among Finnish adolescents. A time-series from 1984 to 2011 was analysed from two large-scale survey studies, the Finnish School Health Promotion Study and the Health Behavior in School-Aged Children study. A total of 1,136,583 adolescents aged 11-18 years answered a standardized questionnaire assessing frequency of insomnia symptoms, tiredness and school performance. A clear approximately twofold increasing trend in insomnia symptoms and tiredness was found from the mid-1990s to the end of the 2000s. The increase was evident in all participating age groups and in both genders. Af…

Pilot study on the validity of the pupillographic sleepiness test in children and adolescents

2013

Abstract Objective To report preliminary validation data for the pupillographic sleepiness test (PST) in children and adolescents. Methods Twelve patients (13.1±4.4years of age) underwent the multiple sleep latency test (MLST) and three PSTs at 09:00, 11:00, and 13:00 on one single day. Correlations were tested between mean sleep latency and gender-adjusted z -values of the natural logarithm of the pupillary unrest index (zlnPUI). Results Spearman's correlation ( P -value) between the zlnPUI values obtained at 09:00 and 11:00 with the MSL was r S =−0.641 (0.025) and r =−0.553 (0.062). Conclusion There was satisfactory agreement between PST and the MLST, which is similar to what is found in …

Validity of the Pupillographic Sleepiness Test for the diagnosis of daytime sleepiness in children and adolescents and its relationship to sleepiness…

2021

Objectives: To report validation data for the Pupillographic Sleepiness Test (PST) in children and adolescents, evaluate its applicability for diagnosing excessive daytime sleepiness and its relationship to sleepiness-associated outcomes. Methods: A cross-sectional diagnostic test accuracy study was performed. Patients underwent three PST at 9 a.m. (T1), 11 a.m. (T2) and 1 p.m. (T3) plus the Multiple Sleep Latency Test (MSLT) on a single day. Additionally, two neurocognitive tests were performed and three questionnaires about quality of life, sleep-related self-efficacy and behavioural aspects completed. Gender-stratified z-values of the natural logarithm of the Pupillary Unrest Index (z-ln…