Primed Tactile Stimulus Processing during Sleep

The aim was to investigate how the primed and unprimed non-painful tactile stimuli during sleep would be processed. A total of 22 healthy subjects (19.55 ± 1.10 years) were randomly divided into two groups. The same stimuli were applied to both groups, but the study group (SG) received them twice (daytime and sleep), whereas the control group (CG) received them only during sleep. A 40-channel PSG and a pneumatic tactile stimulator unit were used. Evoked potential components of the CZ electrode were examined in four sleep stages (N1, N2, N3, and REM). The Mann–Whitney U test was used for group comparison, and the Wilcoxon test was used for in-group evaluations. The P50 and N300 response components were observed in all sleep stages in both groups. P50 decreased as sleep deepened in the SG. The N300 increased as sleep deepened and started to decrease again in the REM stage. Moreover, in N1, the amplitudes of P200-N300 and N300-P450 in the SG were significantly greater than those in the CG. The fact that P50 was observed even in N3 indicates that bottom-up sensory processing continues during sleep. Moreover, the central processing of primed and unprimed stimuli exhibited dynamic differences. Furthermore, an increase in N300 amplitude suggests suppressive processes to facilitate and maintain sleep

Brain responsiveness to non-painful tactile stimuli prior and during sleep

The purpose of this study is analyzing the responses to non-painful tactile stimuli prior-to-sleep (PS) and during the sleep. A total of 21 healthy participants (10 male, mean age +/- SD 22.82 +/- 1.12 years) were recruited and tested in this study. EEG recordings were taken from 40 channels. Single type of non-painful tactile stimuli was applied to the two fingers of the right hand by means of pneumatic stimulator. Sleep stages were scored according to American Academy of Sleep Medicine sleep scoring systems. Somatosensory-evoked potentials (SEPs) were analyzed for PS and each of sleep stages. While P50, N100, P200, N300, P900 and N_late components were recorded both PS and during the sleep, P300 and N450 were observed only in PS. Likewise, P450 and N550 components were observed only during the sleep cycle (light, deep and REM). P50, N100 and P200 components related to sensorial processing had relatively higher amplitudes in PS than in the sleep cycle. On the other hand, N300, P450, P900 and N_late responses had the highest amplitudes during sleep. The changes in brain responses to non-painful tactile stimuli PS and during the sleep were presented in this study. To our knowledge, it is the first study to demonstrate the eight SEP components all at once. Early components have been related to sensory processing and thus hint at the limitation of the brain towards external world for sleep, whereas later components show the network activity for sustaining the sleep environment

Time Estimation and Risk Taking Behavior in Type A Personality

Objective: Studies reported that Type A personality is characterized by ambition, aggression, and impatience. Although there are several studies investigating the relationship between individuals with this personality type and time perception and risk taking behavior, there are no studies investigating the relationship between the personality test scores, time perception, and risk-taking behavior. The main aim of this study is to reveal the relationship between Type A personality test scores, time perception and risk taking behavior

Sleep Is a Refreshing Process: An fNIRS Study

Sleep is a very critical process that constitutes up to one third of daytime of a healthy adult. It is known to be an active period where body and brain is refreshed for the next day. It is both part of a larger cycle, i.e., circadian rhythm, and has subcsycles in it, i.e., sleep stages. Although hemodynamics of these stages have been investigated especially in the last two decades, there are still points in the hemodynamics to be illuminated especially in terms of refreshment. This study aims to investigate refreshing property of sleep in terms of sleep stages using functional near-infrared spectroscopy (fNIRS) for measuring prefrontal cortex (PFC) hemodynamics. Nine healthy subjects slept in sleep laboratories, monitored by polysomnography and fNIRS before, during, and after night sleep. REM stage had lower oxyhemoglobin (HbO) and total hemoglobin (HbT) than the other sleep stages and wakefulness. Deoxyhemoglobin (HbR) did not differ between any stages. All sleep stages and wakefulness stage at the end of the sleep had higher HbO and lower HbR than the beginning of the sleep. HbT levels did not differ between the beginning and the end of the sleep for any stages. During REM sleep, PFC seems to get lower blood supply, possibly due to increased demand in other brain regions. Regardless of the stage, PFC has higher oxygenation toward the end of sleep, indicating refreshment. Overall, our brain seems to be on duty during sleep throughout the night for "cleaning" and "refreshing" itself. Hemodynamic changes from the beginning to end of sleep might be the indicator of this work. Thus, accordingly REM stage seems to be at a central point for this work

VISUAL EVOKED RESPONSES IN ADOLESCENT IDIOPATHIC SCOLIOSIS

Purpose: In electrophysiological studies conducted with adolescent idiopathic scoliosis (AIS) patients, no prior studies examining the visual evoked potentials of AIS patients were found in conjunction with objective vertical perception. The aim of this study was to examine the visual evoked potentials of individuals with AIS and healthy individuals in terms of their brain responses.Material and Methods: Twelve AIS patients (12.75 & PLUSMN;0.86 years) and 10 healthy subjects (13.80 & PLUSMN;1.68 years) participated. A 64-channel electroencephalography (EEG) recording system, Embedded Microcontroller Unit (EMISU), visual stimulation unit, EEG cap, and video recording system were used to examine brain responses after applying visual stimulus.Results: In AIS and control groups (CG), three positive and two negative peaks were observed after applying the stimulus. In the AIS, the first and second negative, and second positive peaks, and in the CG, the second positive and negative peaks appeared significantly earlier in the frontal region. The amplitude of the third positive peak in all regions was found to be higher in the AIS. In AIS and CG, the second positive peak was found to be significantly higher in the parieto-occipital region.Conclusion: It can be judged that AIS patients use more sources for processing the vertical visual stimuli than procedures compared to healthy individuals. In light of the findings obtained, the effect of treatments applied to AIS patients with the method used in this study can be evaluated in terms of brain responsiveness. In addition to the subjective visual perception of individuals with AIS, this method can also evaluate objective vertical perception

Evaluation of the compliance between EEG monitoring (Bispectral Index (TM)) and Ramsey Sedation Scale to measure the death of sedation in the patients who underwent procedural sedation and analgesia in the emergency department

BACKGROUND: This study aimed to investigate the compliance between electroencephalogram monitoring (Bispectral Index, BIS) and Ramsay Sedation Scale (RSS) to measure the depth of sedation in patients who underwent procedural sedation and analgesia (PSA) in an emergency department. This study also aimed to investigate the usefulness of this compliance for early diagnosis of complications