Is decision-making influenced by interactions between extended wakefulness and weak emotional stressors? An experimental study.

In this study, we aimed to determine whether 21-hour continuous wakefulness decreases performance in the Iowa Gambling Task and examine the effect of the interaction between a weak emotional stressor and prolonged continuous wakefulness on the decision-making process, as measured by the Iowa Gambling Task. Approximately half of 38 healthy college students were in the sleep deprivation condition (they performed the task at 4:30 a.m.

Does upper-body elevation affect sleepiness and memories of hypnagogic images after short daytime naps?

The present study aimed to examine the effects of a somatosensory stimulus on sleepiness and memories of hypnagogic imagery during short daytime naps. Participants experienced two daytime nap conditions: (1) a somatosensory stimulus was created by raising the upper part of the bed 20 min after turning off the light and (2) a somatosensory stimulus was not created; the angle of the upper part of the bed remained flat. Approximately 20 min and 30 s after turning off the light, participants were awakened and questioned regarding their subjective sleepiness and the presence or absence of hypnagogic imagery.

The impact of a delayed sleep-wake schedule on depression is greater in women--A web-based cross-sectional study in Japanese young adults.

Sleep-related problems, such as symptoms of insomnia, daytime sleepiness, shorter sleep duration, or a delayed sleep-wake schedule, are known to be risk factors for depression. In general, depression is more prevalent in women than in men, but sleep-related problems do not necessarily show similar gender predominance. Hence, it can be speculated that the impact of sleep-related problems on the development process of depression differs between genders; however, so far, few studies have focused on this issue.

Prevalence and Correlates of Insufficient Sleep Syndrome in Japanese Young Adults: A Web-Based Cross-Sectional Study.

Study Objective: This study investigated the prevalence and risk factors of insufficient sleep syndrome (ISS), and factors associated with daytime dysfunction in the disorder in Japanese young adults.

Methods: In this cross-sectional study, a web-based questionnaire survey was used to assess demographic variables, sleep habits and quality, depressive symptoms, and health-related quality of life (HRQOL) in 2,276 participants aged 20-25.

Results: Eleven percent of participants were classified as having ISS.

Impact of hypnotics use on daytime function and factors associated with usage by female shift work nurses.

Objective: We investigated quality of life (QOL) and work performance of hypnotics users, and explored the factors associated with multiple hypnotics usage in shift work nurses.

Methods: We conducted a questionnaire-based, cross-sectional survey on nurses in university hospitals. We analyzed responses from 1202 nurses; 997 were female shift work nurses (82.

Factors associated with long-term use of hypnotics among patients with chronic insomnia.

This study investigated factors associated with long-term use of benzodiazepines (BZDs) or benzodiazepine receptor agonists (BzRAs) as hypnotics in patients with chronic insomnia. Consecutive patients (n = 140) with chronic insomnia were enrolled in this study (68 men and 72 women; mean age, 53.8 ± 10.

Effect of delayed sleep phase during university life on the daytime functioning in work life after graduation.

Objective: To examine the effects of changes in sleep phase on the daytime functioning of new university graduates.

Methods: Questionnaire data of university students (n = 745) and university graduates working full time (n = 360) were analyzed to explore sleep phase changes during this life stage. The newly graduated full-time workers (n = 117) were divided into 2 (bedtime at investigation: earlier/later) × 2 groups (bedtime at one year prior to investigation: earlier/later), and depressive symptoms and health-related quality of life were compared among groups.

Internet-based survey of factors associated with subjective feeling of insomnia, depression, and low health-related quality of life among Japanese adults with sleep difficulty.

Background: This study was conducted to determine what symptom components or conditions of insomnia are related to subjective feelings of insomnia, low health-related quality of life (HRQOL), or depression.

Method: Data from 7,027 Japanese adults obtained using an Internet-based questionnaire survey was analyzed to examine associations between demographic variables and each sleep difficulty symptom item on the Pittsburgh Sleep Quality Index (PSQI) with the presence/absence of subjective insomnia and scores on the Short Form-8 (SF-8) and Center for Epidemiologic Studies Depression Scale (CES-D).

Results: Prevalence of subjective insomnia was 12.

Factors associated with shift work disorder in nurses working with rapid-rotation schedules in Japan: the nurses' sleep health project.

Workers who meet the criteria for shift work disorder (SWD) have elevated levels of risk for various health and behavioral problems. However, the impact of having SWD on shiftworkers engaged in rapid-rotation schedules is unknown. Moreover, the risk factors for the occurrence of SWD remain unclear.

The effects of a nighttime nap on the error-monitoring functions during extended wakefulness.

Study Objectives: To examine the effects of a 1-hr nighttime nap, and the associated sleep inertia, on the error-monitoring functions during extended wakefulness using the 2 event-related potential components thought to reflect error detection and emotional or motivational evaluation of the error, i.e., the error-related negativity/error-negativity (ERN/Ne) and error-positivity (Pe), respectively.

Change in frequency of periodic limb movements during sleep with usage of continuous positive airway pressure in obstructive sleep apnea syndrome.

Periodic limb movements during sleep (PLMS) sometimes newly appear on the night of continuous positive airway pressure (CPAP) titration in patients with obstructive sleep apnea syndrome (OSAS). To ascertain the incidence and causative factors of this phenomenon, we investigated differences in its prevalence and the factors associated with newly appeared and persistent PLMS on CPAP titration night. We retrospectively analyzed polysomnographic data of 997 consecutive OSAS outpatients who had undergone overnight CPAP titration.

The factors associated with preferences for napping and drinking coffee as countermeasures for sleepiness at the wheel among Japanese drivers.

Objective: We explored differences between professional and non-professional drivers in terms of the factors associated with preferences for generally accepted, effective countermeasures for sleepiness at the wheel--i.e., napping and drinking coffee.

Relationship between napping pattern and nocturnal sleep among Japanese nursery school children.

Background: It has been suggested that the daytime napping patterns of children differ according to racial and cultural backgrounds. The objectives of this study were to describe the daytime nap durations of Japanese nursery school children and to elucidate their relationship to nocturnal bedtimes.

Methods: The mothers of 967 children between 0 and 5 years of age recorded sleep logs for 9 consecutive nights.

Prevalence and clinical characteristics of restless legs syndrome in chronic kidney disease patients.

Objective: To clarify the prevalence of restless legs syndrome (RLS) in the chronic kidney disease (CKD) population and determine the relationship between severity of renal dysfunction and risk of RLS as well as the impact of the disorder on mood and sleep disturbance, we conducted a questionnaire survey followed by face-to-face interviews with Japanese CKD patients.

Methods: We sent a questionnaire battery including demographics items, the National Institutes of Health/International RLS Study Group (IRLSSG) consensus questionnaire, the Center for Epidemiological Studies Depression Scale, and the Pittsburgh Sleep Quality Index to eligible CKD patients (n=514) and age- and sex-matched controls (n=535). Structured interviews were performed for the diagnosis of RLS.

Detecting deteriorated vigilance using percentage of eyelid closure time during behavioral maintenance of wakefulness tests.

Several researchers have investigated the relation between vigilance and ocular variables such as saccade, slow eye movement, pupil, blink, or eyelid closure. This study was undertaken to find the most effective indicator among these ocular variables for evaluating short-term (1 min) fluctuation of vigilance, and to investigate the ability of the most effective ocular variable for predicting deteriorated vigilance during behavioral maintenance of the wakefulness test (Oxford sleep resistance test: OSLER test). Nine healthy volunteers (two women, 19-30 years old, 23.

Relation between morningness-eveningness score and depressive symptoms among patients with delayed sleep phase syndrome.

Objectives: Depressive symptoms are observed in a relatively large series of patients with delayed sleep phase syndrome (DSPS). This study was undertaken to investigate the prevalence, characteristics, and factors associated with depressive symptoms among DSPS patients.

Methods: This study targeted 90 consecutive patients (54 men, 27.

Short sleep duration and irregular bedtime are associated with increased behavioral problems among Japanese preschool-age children.

Sleep problems are known to be risk factors for subsequent emotional and behavioral difficulties in childhood and adolescence. To date, there has been no study investigating the relationships between sleep habits and behavioral problems in a large nonclinical sample of preschool age children. The aim of this study was to examine these relationships and factors associated with the sleep habits of preschool age (2 to 5 year old) children.

Excessive daytime sleepiness among Japanese public transportation drivers engaged in shiftwork.

Objective: To explore the actual condition of sleep disorders underlying subjective excessive daytime sleepiness (EDS) among train and bus drivers engaged in shiftwork.

Methods: This study targeted 3109 public transportation drivers. Clinical diagnoses were made based on 147 drivers who claimed to have subjective EDS, and 285 drivers who were judged to have obstructive sleep apnea syndrome (OSAS), based on the screening process.

Exploring the daily activities associated with delayed bedtime of Japanese university students.

University students show delayed sleep-wake patterns, i.e., later bed- and rise-times, and this pattern is known to be associated with various malfunctions.

Performance monitoring during sleep inertia after a 1-h daytime nap.

Performance monitoring is an essential function involved in the correction of errors. Deterioration of this function may result in serious accidents. This function is reflected in two event-related potential (ERP) components that occur after erroneous responses, specifically the error-related negativity/error negativity (ERN/Ne) and error positivity (Pe).