Search results for "Wakefulne"
showing 10 items of 75 documents
Deviance sensitivity in the auditory cortex of freely moving rats.
2018
Deviance sensitivity is the specific response to a surprising stimulus, one that violates expectations set by the past stimulation stream. In audition, deviance sensitivity is often conflated with stimulus-specific adaptation (SSA), the decrease in responses to a common stimulus that only partially generalizes to other, rare stimuli. SSA is usually measured using oddball sequences, where a common (standard) tone and a rare (deviant) tone are randomly intermixed. However, the larger responses to a tone when deviant does not necessarily represent deviance sensitivity. Deviance sensitivity is commonly tested using a control sequence in which many different tones serve as the standard, eliminat…
Assessing Command-Following and Communication With Vibro-Tactile P300 Brain-Computer Interface Tools in Patients With Unresponsive Wakefulness Syndro…
2018
Persons diagnosed with disorders of consciousness (DOC) typically suffer from motor disablities, and thus assessing their spared cognitive abilities can be difficult. Recent research from several groups has shown that non-invasive brain-computer interface (BCI) technology can provide assessments of these patients' cognitive function that can supplement information provided through conventional behavioral assessment methods. In rare cases, BCIs may provide a binary communication mechanism. Here, we present results from a vibrotactile BCI assessment aiming at detecting command-following and communication in 12 unresponsive wakefulness syndrome (UWS) patients. Two different paradigms were admi…
Valencia Model of Waking Hypnosis: Background, Research, and Clinical Applications
2018
The goal of this article is to provide a comprehensive review of the historical background, methods, and clinical applications of the Valencia Model of Waking Hypnosis (VMWH). The active-alert-waking methods have been developed and used since the 19th century as an alternative when the suggestions for relaxation and drowsiness were not helpful for specific cases, or when the person needed to use hypnotic suggestions in situations that required them to be alert and with their eyes open (i.e. in vivo exposure, sports performance, academic work, etc.). In most of these methods, the hypnotized person keeps their eyes open, and the suggestions given are for alertness, focused attention, mind exp…
Is the nonREM–REM sleep cycle reset by forced awakenings from REM sleep?
2002
In selective REM sleep deprivation (SRSD), the occurrence of stage REM is repeatedly interrupted by short awakenings. Typically, the interventions aggregate in clusters resembling the REM episodes in undisturbed sleep. This salient phenomenon can easily be explained if the nonREM–REM sleep process is continued during the periods of forced wakefulness. However, earlier studies have alternatively suggested that awakenings from sleep might rather discontinue and reset the ultradian process. Theoretically, the two explanations predict a different distribution of REM episode duration. We evaluated 117 SRSD treatment nights recorded from 14 depressive inpatients receiving low dosages of Trimipram…
Large-scale network architecture and associated structural cortico-subcortical abnormalities in patients with sleep/awake-related seizures.
2019
Study objectives In this study, we aimed to estimate the alterations of brain networks and structural integrity linked to seizure occurrence during sleep and awake states. Methods Using a graph theory approach to magnetic resonance imaging-derived volumes of cortical and subcortical regions, we investigated the topological organization of structural networks in patients with sleep seizures (n = 13), patients with awake seizures (n = 12), and age- and sex-matched healthy controls (n = 10). Abnormalities in regional structural substrates (cortical volume/surface area, subcortical volumes) associated with sleep seizures and awake seizures were further analyzed. Results Brain networks in patien…
Processing of auditory stimuli during tonic and phasic periods of REM sleep as revealed by event-related brain potentials
1996
The brain has been reported to be more preoccupied with dreams during phasic than during tonic REM sleep. Whether these periods also differ in terms of the processing of external stimuli was examined. Event-related brain potentials (ERPs) to a frequent standard tone of 1000 Hz (P = 97%) and infrequent deviant tones of 1100 and 2000 Hz (P = 1.5% for each) were recorded (n = 13) during wakefulness and nocturnal sleep. An ERP wave (called REM-P3) resembling a waking P3 wave was larger for the 2000 Hz deviant during tonic than during phasic REM sleep. Also the P210 wave was larger during tonic than during phasic REM sleep. A reliable mismatch negativity component appeared only in wakefulness. I…
The effects of post-awakening light exposure on the cortisol awakening response in healthy male individuals.
2019
Abstract Background It is assumed that the expression of the cortisol awakening response (CAR) is modulated by light exposure during the peri-awakening period. While initial evidence supports this principal effect, the specific role of the spectral composition of light (brightness and wavelength) is still incompletely understood. Method Two counterbalanced within-subject experiments were conducted in a standardized sleep laboratory setting to investigate the effect of light intensity (study I; two days: dim vs. bright light) and spectral composition (study II; three days: red vs. blue vs. green light) on the CAR. Across studies, light exposure was conducted for one-hour post-awakening and t…
Methylphenidate, modafinil, and caffeine for cognitive enhancement in chess: A double-blind, randomised controlled trial.
2017
Stimulants and caffeine have been proposed for cognitive enhancement by healthy subjects. This study investigated whether performance in chess - a competitive mind game requiring highly complex cognitive skills - can be enhanced by methylphenidate, modafinil or caffeine. In a phase IV, randomized, double-blind, placebo-controlled trial, 39 male chess players received 2×200mg modafinil, 2×20mg methylphenidate, and 2×200mg caffeine or placebo in a 4×4 crossover design. They played twenty 15-minute games during two sessions against a chess program (Fritz 12; adapted to players' strength) and completed several neuropsychological tests. Marked substance effects were observed since all three subs…
Preference between two methods of active-alert hypnosis: not all techniques are created equal.
1999
Abstract In a cross-over design (N = 80), we compared the differential liking and preference for two hypnotic techniques involving physical activity: Active-alert and waking-alert (or alert-hand) procedures. Participants expressed significantly higher liking and preference for the waking-alert as compared to the active-alert procedure. The latter technique, which also had significantly lower suggestibility scores (Cardena et al., 1998) was also associated with a significantly higher attrition rate (23%). These significant differences may be explained by the greater physical effort and difficulty associated with the active-alert technique. It seems that the waking-alert method extends the ad…
Cutaneous Painful Laser Stimuli Evoke Responses Recorded Directly From Primary Somatosensory Cortex in Awake Humans
2004
Negative and positive laser evoked potential (LEP) peaks (N2*, P2**) were simultaneously recorded from the primary somatosensory (SI), parasylvian, and medial frontal (MF: anterior cingulate and supplementary motor area) cortical surfaces through subdural electrodes implanted for the surgical treatment of intractable epilepsy. Distribution of the LEP N2*and P2**peaks was estimated to be in cortical areas (SI, parasylvian, and MF) identified by anatomic criteria, by their response to innocuous vibratory stimulation of a finger (v-SEP), and to electrical stimulation of the median nerve (e-SEP). The maximum of the LEP N2*peak was located on the CS, medial (dorsal) to the finger motor area, as …