Biomedical subjects

Marianne Byström

Publications and source records attributed to Marianne Byström.

3 recordsLinked to original sources

PubMed2004

Missing a meal: effects on alertness during sedentary work.

The purpose of this investigation was to evaluate the acute effects of missing a meal on alertness. The participants were ten university students between 20-29 years old, five females and five males. Participants were chosen on the basis of their good sleep and eating practices. Measurements were collected during an eight hour period starting at 8.00 AM on four separate days. During the test period, participants carried out their normal study activities while on separate days receiving either just breakfast, just lunch, both lunch and breakfast, or no meal at all. During the test period, EEG was monitored continuously while subjective ratings of performance and tiredness were collected every half-hour. The results showed that while there were neither physiological nor subjective indications of tiredness which could be attributed to meal consumption, subjective feelings of lack of energy and motivation was significantly more pronounced at the end of the workday when missing a meal or two.

Adult↗

PubMed2004

Effect on truck drivers' alertness of a 30-min. exposure to bright light: a field study.

Reduced alertness is common during night driving. Light treatment may constitute one countermeasure to reduce sleepiness. To test this idea six professional drivers participated in this study in which they self-administered a 30-min. light treatment during a break in the middle of a night drive of about 9 hours. Two experimental conditions were used, including light exposures with a light box and a light visor. There was a control condition. Alertness was measured on a 100-mm visual analogue scale. No significant effect of light was found, but ratings of sleepiness increased significantly through the night drive. The experimental light treatment was not correlated with any increased wakefulness compared to the drivings where no extra light exposures were carried out.

Adult↗

PubMed2003

Bright light as a sleepiness prophylactic: a laboratory study of subjective ratings and EEG.

Sleepiness is a major problem when driving a vehicle and contributes to 15 to 30% of all road accidents. One possible countermeasure may be exposure to light. This study was designed to test whether 30 min. of exposure to a bright light would reduce subjective sleepiness and EEG indicators of sleepiness, such as alpha and theta power density. 10 female and 10 male university students (recruited through advertisements) participated in a laboratory study, consisting of 30 min. of dim light followed by 30 min. of bright light (or red light in the control condition) exposures and then by 30 min. of dim light exposure. In the dim light exposure, the luminance was 20 cd/m2, and the illuminance was about 5 Lux. In the bright exposure, the luminance was 500 cd/m2 and the illuminance about 2000 Lux. In the red light exposure, the luminance was 10 cd/m2 and the illuminance about 30 Lux. The subject sat in a chair with a seating comfort corresponding to that of a driver's seat. Analysis showed that the subjects became subjectively sleepier during the pre-exposure condition, and alpha and theta power density increased in their EEGs. The intervention significantly reduced subjective sleepiness but did not have significant effects on alpha or theta power density. The results suggest that a short (30 min.) exposure to bright light may not be a useful prophylactic against sleepiness for the period following the exposure.

Adult↗