STUDY OBJECTIVES The purpose was to remedy the lack of experimental studies directly comparing the effects of brief and long daytime naps following nocturnal sleep restriction. DESIGN Twelve young adult healthy sleepers participated in a repeated measures design comparing the effects of no nap, a 10-minute nap, and a 30-minute afternoon nap in each case following a night of 4.7 hours of total...

Mathematical models of neurobehavioral performance and alertness have both basic science and practical applications. These models can be especially useful in predicting the effect of different sleep-wake schedules on human neurobehavioral objective performance and subjective alertness under many conditions. Several relevant models currently exist in the literature. In principle, the development...

The influence of motivation and alertness on brain activity associated with visual perception was studied experimentally using the Necker cube, which ambiguity was controlled by the contrast of its ribs. The wavelet analysis of recorded multichannel electroencephalograms (EEG) allowed us to distinguish two different scenarios while the brain processed the ambiguous stimulus. The first scenario ...

In tasks requiring sustained attention, human alertness varies on a minute time scale. This can have serious consequences in occupations ranging from air traac control to monitoring of nuclear power plants. Changes in the electroencephalographic (EEG) power spectrum accompany these uctuations in the level of alertness, as assessed by measuring simultaneous changes in EEG and performance on an a...

background: this paper investigated the effect of daylight on morning and night melatonin, subjective general health using ghq questionnaire, sleepiness and alertness on elderly who lived in nursing houses. methods: nineteen nursing home residents participated voluntarily. they exposed to daylight from 9 to 10 a.m. and from 4 to 5 p.m. for 6 wk. the level of melatonin in the morning and at nigh...

This study was conducted among health care personnel (registered nurses and nurse aides) in a public hospital in São Paulo, Brazil. Work was organized in 12-hour daytime or nighttime shifts, followed by 36 hours off. The study aimed to evaluate how the nursing staff perceived the duration and quality of sleep both during and off work days, as well as their perception of alertness during working...

PURPOSE Road traffic accidents are one of main problems in Iran. Multiple factors cause traffic accidents and the most important one is sleepiness. This factor, however, is given less attention in our country. Road traffic accidents relevant to sleepiness are studied. METHODS In this cross-sectional study, all road traffic accidents relevant to sleepiness, which were reported by police, were ...

We studied top-down attentional effects on adaptation to two aspects of sinusoidal gratings: contrast (CTE: contrast threshold elevation for detection) and orientation (TAE: tilt aftereffect, bias in perceived orientation). Adaptation was examined under five different behavioral conditions designed to assess the effect of alertness, spatial attention and the dimension attended. Alertness increa...

Adults with attention deficit hyperactivity disorder (ADHD) show attentional dysfunction such as distractibility and mind-wandering, especially in lengthy tasks. However, fundamentals of dysfunction are ambiguous and relationships of neuropsychological test parameters with self-report measures of ADHD symptoms are marginal. We hypothesize that basic deficits in sustaining attention explain more...

Both physical and mental effort are thought to affect vigilance. Mental effort is known for its vigilance declining effects, but the effects of physical effort are less clear. This study investigated whether these two forms of effort affect the EEG and subjective alertness differently. Participants performed a physical task and were subsequently presented with a mental task, or vice versa. Ment...