Acute alerting effects of daytime exposure to specific wavelengths of light [ 2007 - 2009 ]

Research Grant

Researchers: Prof Shanthakumar Wilson Rajaratnam (Principal investigator) ,  Jennifer Redman ,  Prof Steven Lockley

Brief description 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.

Funding Amount $AUD 446,367.15

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant