Simulated driving performance following prolonged wakefulness and alcohol consumption: Separate and combined contributions to impairment

Department of Psychology, Queen's University, Kingston, Ontario, Canada.
Journal of Sleep Research (Impact Factor: 3.35). 10/2000; 9(3):233-41. DOI: 10.1046/j.1365-2869.2000.00216.x
Source: PubMed


The separate and combined effects of prolonged wakefulness and alcohol were compared on measures of subjective sleepiness, simulated driving performance and drivers' ability to judge impairment. Twenty-two males aged between 19 and 35 years were tested on four occasions. Subjects drove for 30 min on a simulated driving task under conditions determined by the factorial combination of 16 and 20 h of wakefulness and blood alcohol concentrations of 0.00 and 0.08%. The simulated driving session took place 30 min postingestion; subjects in the two alcohol conditions participated in a second 30-min driving session 90-min postingestion. Subjects made simultaneous ratings of their impairment while driving and retrospective ratings at the end of each test session. Subjective sleepiness measures were completed before and after each driving session. The combination of 20 h of prolonged wakefulness and alcohol produced significantly lower ratings of subjective sleepiness and driving performance that was worse, but not significantly so, than would be expected from the additive effects of each condition alone. Driving performance was always worse in the second driving session, during the elimination phase of alcohol metabolism, despite blood alcohol concentrations being lower than during the first driving session. There was a modest association between perceived and actual impairments in driving performance following prolonged wakefulness and alcohol. The findings suggest that the combination of prolonged wakefulness and alcohol consumption produced greater decrements in simulated driving performance than each condition alone and that drivers have only a modest ability to appreciate the magnitude of their impairment.

Download full-text


Available from: Alistair W Maclean, Sep 10, 2014
  • Source
    • "Several studies have noted that driving performance is adversely affected by sleepiness (A ˚ kerstedt, 2000; A ˚ kerstedt et al., 2005; Arnedt et al., 2000; Biggs et al., 2007; Gillberg et al., 1996a; Lenne et al., 1998; Otmani et al., 2005; Vakulin et al., 2007). We observed a significant increase in subjective sleepiness (KSS) across the study period. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Breaks are often used by drivers to counteract sleepiness and time-on-task fatigue during prolonged driving. We examined the temporal profile of changes in driving performance, electroencephalogram (EEG) activity and subjective measures of sleepiness and fatigue during prolonged nocturnal driving in a car simulator. In addition, the study examined the impact of regular breaks from driving on performance, sleepiness and fatigue. Healthy volunteers (n=12, 23-45 years) maintained a regular sleep-wake pattern for 14 days and were then in a laboratory from 21:00 to 08:30 hours. The driving simulator scene was designed to simulate monotonous night-time rural driving. Participants drove 4 × 2-h test sessions, with a break from driving of 1 h between each session. During the break participants performed tests assessing sleepiness and fatigue, and psychomotor performance (~30 mins), and then were permitted to sit quietly. They were monitored for wakefulness, and not permitted to nap or ingest caffeine. EEG was recorded during the driving task, and subjective assessments of sleepiness and fatigue were obtained at the start and completion of each session. We found that driving performance deteriorated (2.5-fold), EEG delta, theta and alpha activity increased, and subjective sleepiness and fatigue ratings increased across the testing period. Driving performance and fatigue ratings improved following the scheduled breaks from driving, while the breaks did not affect EEG activity and subjective sleepiness. Time-on-task effects increased through the testing period, indicating that these effects are exacerbated by increasing sleepiness. Breaks from driving without sleep temporarily ameliorate time-on-task fatigue, but provide little benefit to the sleepy driver.
    Preview · Article · Dec 2010 · Journal of Sleep Research
  • Source
    • "In addition, the increased lateral variability of lane position is an established effect of sleep loss in driving (A ˚ kerstedt et al., 2005; Arnedt et al., 2000; Brookhuis et al., 2003; Contardi et al., 2004; OÕHanlon and Kelly, 1974; OÕHanlon and Kelley, 1977; Otmani et al., 2005b; Philip et al., 2005b), and which here is extended to the simultaneous effects of TOD and TOT. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Studies of driving and sleepiness indicators have mainly focused on prior sleep reduction. The present study sought to identify sleepiness indicators responsive to several potential regulators of sleepiness: sleep loss, time of day (TOD) and time on task (TOT) during simulator driving. Thirteen subjects drove a high-fidelity moving base simulator in six 1-h sessions across a 24-h period, after normal sleep duration (8 h) and after partial sleep deprivation (PSD; 4 h). The results showed clear main effects of TOD (night) and TOT but not for PSD, although the latter strongly interacted with TOD. The most sensitive variable was subjective sleepiness, the standard deviation of lateral position (SDLAT) and measures of eye closure [duration, speed (slow), amplitude (low)]. Measures of electroencephalography and line crossings (LCs) showed only modest responses. For most variables individual differences vastly exceeded those of the fixed effects, except for subjective sleepiness and SDLAT. In a multiple regression analysis, SDLAT, amplitude/peak eye-lid closing velocity and blink duration predicted subjective sleepiness bouts with a sensitivity and specificity of about 70%, but were mutually redundant. The prediction of LCs gave considerably weaker, but similar results. In summary, SDLAT and eye closure variables could be candidates for use in sleepiness-monitoring devices. However, individual differences are considerable and there is need for research on how to identify and predict individual differences in susceptibility to sleepiness.
    Full-text · Article · Jun 2010 · Journal of Sleep Research
  • Source
    • "After this time period of sleep loss, decrements in participants' performance are equivalent to that observed at a blood alcohol concentration of 0.05% (Dawson and Reid 1997). However, the effect of extended wakefulness on performance decrements may be confounded by circadian phase (Arnedt et al. 2000). The significant decrements in performance and subjective sleepiness observed at 03:45 h in the current study are therefore likely to be a result of a combination of prior wakefulness and circadian factors. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Sleepiness due to sleep loss and circadian factors can have a detrimental effect on performance, and contribute to road and workplace accidents. A brief nap taken during or immediately before a night shift may alleviate sleepiness both at work and on the road after work. This study investigated the effects of a 30-minute napping opportunity before or during an actual night shift. Performance was evaluated in three repeated-measures, crossover conditions; a nap prior to night shift (20:15 h), a nap during night shift (04:00 h) and no nap. Eight healthy nightshift workers completed a simulated driving task, the Psychomotor Vigilance Task and the Karolinska Sleepiness Scale at the start, end, and during an actual night shift. No significant improvement in performance was observed at the end of the night shift in either nap condition. A 30-minute napping opportunity was not sufficient to overcome the deleterious effects of sleep loss and circadian effects on performance during a first night shift, with no prior daytime sleep.
    Full-text · Article · Apr 2010 · Biological Rhythm Research
Show more