Acute Alerting Effects Of Daytime Exposure To Specific Wavelengths Of Light
Funder
National Health and Medical Research Council
Funding Amount
$446,367.00
Summary
Excessive sleepiness is the greatest identifiable and preventable cause of accidents in all modes of transportation. Shift workers working outside the 8am-5pm day, make up about 20% of the urban working population. These individuals often report excessive daytime sleepiness caused by irregular sleep-wake patterns and long-term sleep loss. Excessive sleepiness is also common in individuals with sleep disorders. While there are many stimulant and wake-promoting drugs available to counteract daytim ....Excessive sleepiness is the greatest identifiable and preventable cause of accidents in all modes of transportation. Shift workers working outside the 8am-5pm day, make up about 20% of the urban working population. These individuals often report excessive daytime sleepiness caused by irregular sleep-wake patterns and long-term sleep loss. Excessive sleepiness is also common in individuals with sleep disorders. While there are many stimulant and wake-promoting drugs available to counteract daytime fatigue such drugs have problems of side effects, interactions and in some cases dependence. Light has many beneficial effects for a wide range of medicinal, physiological, psychological, and social purposes. One well known effect is as a stimulant so that exposure to bright light, both during the night and in the middle of the day, improves alertness and attention, and decreases reaction times thus improving performance. These effects can also be measured as changes in brain activity. However we do not understand the mechanisms in the eyes which control these effects. While certain cells in the eyes called rods and cones are necessary for seeing objects clearly and for detecting colour, there appears to be another system in the eyes which may involve different specialized cells or photoreceptors that are important for the alerting effects of light. White light is made up of different wavelengths or colours of light. This study will examine which wavelength (blue, violet, red or green) of light best improves alertness and learning during the daytime. Various performance tests will be used in addition to measures of brain wave activity. By identifying the most effective wavelength of light for improving alertness in healthy young adults and better understanding the mechanisms in the eyes involved, we will be able to develop light treatment strategies in patient groups with sleep disorders and in individuals like shift workers who experience sleep loss.Read moreRead less
Adult non-Hodgkin?s lymphoma (NHL) is one of the most rapidly increasing cancers of recent times. The rise has occurred worldwide in men and women of all ages. The reason for most of the rise is unknown. It has recently been proposed that part of the upsurge may be due to increases in sun exposure which have occurred during the same period. There is some indirect evidence to support this hypothesis. For example, the rate of occurrence of NHL is higher closer to the equator in Australia than it i ....Adult non-Hodgkin?s lymphoma (NHL) is one of the most rapidly increasing cancers of recent times. The rise has occurred worldwide in men and women of all ages. The reason for most of the rise is unknown. It has recently been proposed that part of the upsurge may be due to increases in sun exposure which have occurred during the same period. There is some indirect evidence to support this hypothesis. For example, the rate of occurrence of NHL is higher closer to the equator in Australia than it is in England and Wales, and NHL is diagnosed more frequently among British migrants to Victoria than it is in their homeland. The sunlight hypothesis will be tested by comparing the pattern of sun exposure in Tasmanians diagnosed with NHL during the years 1998-2001 and in a sample of Tasmanians without the disease. tasmania has been chosen because levels of ultraviolet (UV) radiation are low there in all but the summer months, when it approaches the levels of Brisbane, Sydney and Melbourne. There is therefore a greater difference in UV exposure between the most exposed and the least exposed in Tasmania, making it an ideal location to test the hypothesis. The link between NHL and a measure of melanin pigmentation in the skin will also be studied. The incidence of NHL is higher in lighter-skinned ethnic groups than it is in darker-skinned people living at the same latitude, but it is not known whether risk varies within Caucasian populations. A new measure of melanin in the skin, developed at the Menzies Centre for Population Health Research in Hobart, will better allow the effects of skin colour to be studied.Read moreRead less