Biomaterial Database

Daytime vigilance after morning bright light exposure in volunteers subjected to sleep restriction. 1998

C Lafrance, and M Dumont, and P Lespérance, and C Lambert

Laboratoire de Chronobiologie, Hôpital du Sacré-Coeur de Montréal, Canada.

This study was designed to test the hypothesis that bright light (BL) can have a stimulating effect on vigilance even in the absence of suppression of melatonin secretion and that this effect can be detected when measured in subjects with low vigilance levels. Seven normal subjects were exposed to bright-white light (BL group) and seven to dim-red light (DL group) on 2 consecutive days, each following a night of 4-h sleep restriction. The light treatment was administered in the late morning, between 0900 and 1330 hours. Salivary melatonin measurements indicated that BL did not suppress melatonin secretion or induce circadian phase shifts. The effects of the two treatments were compared on validated measures of daytime vigilance: immediate effects were evaluated on subjective alertness during the light treatment, whereas short-term (0.5-10.5 h) and long-term (20.5-34.5 h) carryover effects were measured on subjective alertness, daytime sleep latencies (DSL), and psychomotor performance. After two nights of sleep restriction, subjective alertness and daytime sleep latencies decreased significantly, but there was no effect of the light treatment. BL treatment did not affect global performance, but there was an effect on the strategy used by the subjects, as shown by faster reaction times and increased percentage of errors in the BL group. It was concluded that daytime BL exposure did not have a stimulating effect on our measures of vigilance even in sleep-deprived subjects but that it may increase physiological arousal and affect the subjects' behavior in some specific performance tasks.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008550	Melatonin	A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
D010789	Phototherapy	Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths.	Blue Light Therapy,Blue-light Therapy,Light Therapy,Photoradiation Therapy,Red Light Phototherapy,Therapy, Photoradiation,Blue Light Therapies,Blue-light Therapies,Light Phototherapies, Red,Light Phototherapy, Red,Light Therapies,Light Therapies, Blue,Light Therapy, Blue,Photoradiation Therapies,Phototherapies,Phototherapies, Red Light,Phototherapy, Red Light,Red Light Phototherapies,Therapies, Blue Light,Therapies, Blue-light,Therapies, Light,Therapies, Photoradiation,Therapy, Blue Light,Therapy, Blue-light,Therapy, Light
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D001288	Attention	Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.	Focus of Attention,Selective Attention,Social Attention,Attention Focus,Attention, Selective,Attention, Social,Selective Attentions
D012892	Sleep Deprivation	The state of being deprived of sleep under experimental conditions, due to life events, or from a wide variety of pathophysiologic causes such as medication effect, chronic illness, psychiatric illness, or sleep disorder.	Inadequate Sleep,Insufficient Sleep,Insufficient Sleep Syndrome,REM Sleep Deprivation,Sleep Debt,Sleep Fragmentation,Sleep Insufficiency,Deprivation, REM Sleep,Deprivation, Sleep,Fragmentation, Sleep,Insufficiencies, Sleep,Insufficiency, Sleep,Insufficient Sleep Syndromes,Sleep Deprivation, REM,Sleep Insufficiencies,Sleep, Inadequate,Sleep, Insufficient,Syndrome, Insufficient Sleep