The aim of the present study is to analyse factors affecting worries, coping strategies and decisions of young drivers regarding the risk of sleep-related car crashes. Furthermore, the study also analyses whether framing the same information about sleepiness in two different linguistic forms influences: (1) the evaluation of the level of risk associated to a specific level of drowsiness (Attribute Framing problem); (2) the willingness to enact strategies to "prevent" sleepiness before night-time driving (Goal Framing problem); (3) the choice between two different ways, both of equal expected efficacy, of lowering drowsiness (Risky decision-making Framing problem). Six hundred and ninety-five young drivers [(57.6% females, 42.4% males); mean age 20.85 years (S.D.=1.2)] answered questions on drive risk perception and sleepiness, on nocturnal driving experience and on the strategies to deal with driver sleepiness, responding to one of the two different versions of the framed problems. A sub-sample of 130 participants completed the framed problems in both versions. The results show that experiences of sleep attacks and nocturnal driving frequency in the past 6 months affect both risk perception and the preventive strategies adopted. Furthermore, the manipulation on two out of the three problems (attribute and risky decision-making frames) significantly affected the respondents' evaluation.

STUDY OBJECTIVE:The aim of this study is to evaluate whether the cortical arousal level in subjects with primary insomnia varies according to their quality of nighttime sleep.DESIGN:The P300 ERP was recorded each day, before and after sleep actigraphically monitored for 1 week. For each participant, the nights of worst- and best-quality sleep were identified.PARTICIPANTS:Seven subjects with primary insomnia and 7 control subjects.MEASUREMENTS AND RESULTS:The P300 amplitudes were compared by considering group (insomnia vs control), night (worst vs best), and moment of recording (before vs after sleep) as factors. The subjects with insomnia showed higher P300 amplitudes, as compared with amplitudes of control subjects, only for the worst night of sleep.CONCLUSIONS:Results indicate a relationship between variations in sleep quality and cortical arousal level in subjects with primary insomnia.

Sleep onsets in the diurnal multiple sleep latency test (MSLT), following different sleep lengths of the preceding night sleep (8, 5, 4, 3, 2, 1 h) and following the corresponding recovery nights, were considered for a study on changes of oculomotor activity during sleep onset. The study aimed to assess the individual time course in spontaneous blinks (SBs) and slow eye movements (SEMs) during the sleep onset period and also the relationship with sleep latencies in the MSLT. Group analyses compared oculomotor changes between conditions characterized by a different level of daytime sleepiness. The results show a clear inverse relation between the two oculomotor measures, with a linear SB decrease and quadratic SEM increase across the wake-sleep transition. A 150 s sample of SB and SEM activity at the start of MSLT trials correlates with individual subsequent sleep latency. Finally, mean changes in daytime sleepiness as measured by the MSLT are paralleled by coherent oculomotor changes, with a significant linear decrease of SB as sleepiness increases as a consequence of previous sleep reduction. Both individual and group results show that endogenous blinking is associated with moderate changes in daytime sleepiness.

The SDQ is a brief self-report insomnia questionnaire, which permits the rapid evaluation of insomnia based on the DSM-IV and ICSD-R criteria. The SDQ was developed to provide a fast and valid instrument both for the pre-screening of subjects who complain of insomnia and for epidemiological studies based on standardized definitions of this sleep disorder. Two studies were carried out in order to assess the validity of the SDQ as a self-report measure of insomnia. In the first study the convergent validity of the SDQ was assessed with respect to the global score of the Pittsburgh Sleep Quality Index (PSQI) in a sample of general practitioners' patients. The second study assessed the sensitivity and the specificity of the SDQ in discriminating between insomniacs or normal sleepers in a sample of college students who were given an extensive sleep evaluation within an insomnia counseling program. The SDQ classifications have a good convergent validity with the global sleep quality scores of the PSQI and its classifications of students who complain of or who do not complain of problems of insomnia have a sensitivity of 95% and a specificity of 87%. Results indicate that the SDQ is a valid paper and pencil instrument to screen insomnia.

Introduction: The Epworth sleepiness scale (ESS) is widely used as a way of measuring subjective sleep propensity in research and clinical practice. Psychometric studies do not rule out the presence of more than one latent dimension underlying the items. Objective: Aims of the present study were to: (a) evaluate psychometric proprieties of the ESS by means of classic psychometric techniques; (b) compare them with those from a newly developed resistance to sleepiness scale (RSS); (c) evaluate, following the latent trait theory, whether the items of both ESS and RSS could be conceptualized as different levels of an interval variable representative of a single latent trait related to sleep propensity. Methods: One hundred and forty-six inpatients suffering from different sleep disorders filled in both the RSS and ESS in a sleep disorder centre. Results: Indexes of fit derived by the application of the extended logistic model are consistent with the idea that each ESS item can be conceptualized as different levels of an interval variable representative of a single latent trait. However, most of the ESS items are found to be located at the opposite extremes of this continuum. Conclusions: The under representation of situations characterized by an intermediate soporific nature in the ESS could limit ESS sensitivity to detect intermediate variations of sleep propensity.

Objective: The hyperarousal hypothesis is evaluated while controlling the influence of the quality of sleep in the night preceding the evaluation. Method: Eleven primary insomniacs and 11 healthy age matched controls participated to the study. Participants filled in 2 weeks of sleep logs and self-monitored their subjective tension the evening before and the morning after each night. Afterwards, subjects were called in to the Lab for a recording session of the P300 ERP (oddball paradigm) once after a night of bad sleep quality (N -) and once after a night of good sleep quality (N+). Results: The main result of the present study indicated that the P300 amplitude at Fz in insomniacs resulted higher following a N - and lower following a N+ with respect to controls. Conclusions: This result suggests that cortical hyperarousal in primary insomniacs is not a stable individual characteristic, but is associated with the poor quality of their nocturnal sleep. (C) 2003 Elsevier Science Inc. All rights reserved.

The vigilance levels of a group of 59 students were assessed in the daytime (9:00-11:00 a.m.) and again early Sunday morning (2:30-5:00 a.m.), and were then compared. Data were collected at the students' schools. The differences in performance impairment associated with different Saturday night social activities and the effect of alcohol consumption were evaluated. Results indicate a vigilance decrease during the night, and this is greater in subjects who consumed more alcohol. Students who spent their Saturday night in a discotheque showed the most prominent nocturnal vigilance decrease, even when the effect of alcohol consumption is covaried. The effect of social activities on vigilance levels was also associated with different lengths of time spent awake and the different time in which subjects performed the vigilance task.

This study evaluated the effects of different amounts of sleep and SWS restriction on the ensuing day-time sleepiness. Six healthy selected males, after one adaptation night and an initial 8-hr baseline night, were allowed to sleep 5, 4, 3, 2, and 1 hr with a 1-week interval between conditions. The following day, 4 sleep onset MSLT trials and 2 Wilkinson Auditory Vigilance Task (WAVT) were administered. Before each MSLT, self evaluations of sleepiness and activation on a visual analogue scale (ADAS) were assessed. Each restriction night was followed by an 8-hr recovery night, and a final 8-hr baseline night was recorded. The day after each night the same diurnal tests were repeated. Results indicated a linear increase in the propensity to sleep (MSLT) and of subjective sleepiness as a function of the increase in sleep restrictions. Performance scores (WAVT) showed that vigilance is partially affected by sleep restrictions. For each measure, regression analyses showed that the effect of sleep reduction is better predicted by the total duration of sleep than by the amount of SWS. Correlations between measures were negligible with the exception of those between performance and subjective sleepiness measures.