Effects of an afternoon nap on nighttime alertness and performance in long-haul drivers

ArticleinAccident Analysis & Prevention 34(6):825-34 · December 2002with15 Reads
DOI: 10.1016/S0001-4575(01)00089-6 · Source: PubMed
The effects of an afternoon nap on alertness and psychomotor performance were assessed during a simulated night shift. After a night of partial sleep restriction, eight professional long-haul drivers either slept (nap condition) or engaged in sedentary activities (no-nap condition) from 14:00 to 17:00 h. Alertness and performance testing sessions were conducted at 12:00 (pre-nap baseline), 24:00, 02:30, 05:00 and 07:30 h, and followed 2-h runs in a driving simulator. In the nap condition, the subjects showed lower subjective sleepiness and fatigue, as measured by visual analog scales, and faster reaction times and less variability on psychomotor performance tasks. Electrophysiological indices of arousal during the driving runs also reflected the beneficial effects of the afternoon nap, with lower spectral activity in the theta (4-7.75 Hz), alpha (8-11.75 Hz) and fast theta-slow alpha (6-9.75 Hz) frequency bands of the electroencephalogram, indicating higher arousal levels. Thus, a 3-h napping opportunity ending at 17:00 h improved significantly several indices of alertness and performance measured 7-14 h later.
    • "In spite of the insignificance of the basic index y, index (a+y)/b showed different statistical characteristics compared to index b/a due to the mutual addition effect of alpha waves and theta waves during the repetitive phase transition between wakefulness and microsleep. According to the EEG study of long distance driving done by Macchi et al. (2002), theta waves alone showed insignificant effect, but the index containing both theta and alpha band showed significant effect. There were significant differences between EEG indices before and after the accidents. "
    [Show abstract] [Hide abstract] ABSTRACT: Advances in materials engineering, electronic circuits, sensors, signal processing and classification techniques have allowed computational systems to interpret biological quantities, recognizing physiological conditions. The next scientific challenge is to turn those technologies portable, wearable or even implantable, above all, being energy efficient. A prospective application for the next generation of portable electroencephalogram (EEG) signal processing systems is hazard prevention in attention-demanding activities. EEG keep closest connection to the preoptic area where sleep is originated. In this paper, a methodology for assessing alertness level based on a single EEG channel (Pz-Oz) is proposed, allowing the reduction of the required hardware and the computational time of the algorithms, besides being more portable than multi-channel based ones. Two new spectral power-based indices (i) γ/δ and (ii) ( )/( ) are computed from EEG rhythms through the normalized Haar discrete wavelet packet transform (WPT). The Haar WPT allows precisely resolving the brain rhythms into packets whilst demanding a relatively low computational cost. The effectiveness of the proposed indices in drowsiness detection is evaluated by comparison with five indices originally proposed for multi-channel processing. Statistical Wilcoxon signed rank test is applied to evaluate the performance of the entire set of indices, evidencing the significant changes in the alert-drowsy transitions of 20 subjects of a public database. The proposed indices (ii) and (i) presented the most and second more significant p-values (p < 0.001 and p=0.001), respectively.
    Article · Mar 2016
    • "Nap could function in managing sleep deprivation and arrhythmia (abnormal heartbeat) due to interfered circadian cycle (Verrier and Josephson 2009). The midday nap could function in recovering negative physical and psychological symptoms due to interfered night sleep (Bonnefond et al. 2001; Macchi et al. 2002) or narcolepsy (Takahashi 2003). It has been reported that 20%-40% of healthy adults are non-nappers (Pilcher et al. 2001). "
    [Show abstract] [Hide abstract] ABSTRACT: Napping/siesta during the day is a phenomenon, which is widely practised in the world. However, the timing, frequency, and duration may vary. The basis of napping is also diverse, but it is mainly done for improvement in alertness and general well-being. Neuroscience reveals that midday napping improves memory, enhances alertness, boosts wakefulness and performance, and recovers certain qualities of lost night sleep. Interestingly, Islam, the religion of the Muslims, advocates midday napping primarily because it was a practice preferred by Prophet Muhammad (pbuh). The objectives of this review were to investigate and compare identical key points on focused topic from both neuroscientific and Islamic perspectives and make recommendations for future researches.
    Full-text · Article · Aug 2015
    • "Several researchers indicated a relationship between cognitive task length and response time. Firstly, Levitt and Gutin (1971) found a non-monotonic effect on reaction time while Macchi et al. (2002) found a positive relationship between response time and cognitive task length; Furthermore, Boksem et al. (2005) found a mixed relationship based on post error responses which was negative and post correct responses which was positive after either a medium or longhaul physical task performance. "
    [Show abstract] [Hide abstract] ABSTRACT: Some theoretical control models posit that the fatigue which is developed during physical activity is not always peripheral and it is the brain which causes this feeling of fatigue. This fatigue develops due to a decrease of metabolic resources to and from the brain that modulates physical performance. Therefore, this research was conducted to find out if there was finite level of metabolic energy resources in the brain, by performing both mental and physical activities to exhaustion. It was found that there was an overflow of information during the exercise-involved experiment. The circular relationship between fatigue, cognitive performance and arousal state insinuates that one should apply more effort to maintain performance levels which would require more energy resources that eventually accelerates the development of fatigue. Thus, there appeared to be a limited amount of energy resources in the brain as shown by the cognitive performance of the participants.
    Full-text · Article · Mar 2015
Show more