|VISUAL PERCEPTION LABORATORY|
Project Title: Alcohol Effects on Visual Processing in At-Risk Social Drinkers
Heavy alcohol drinking among young adults is a serious problem in the United States. One of the most severe consequences of excessive drinking among young adults is unintentional injury or accidents. In 2009, 43% of drunk drivers that were involved in fatal vehicle crashes were aged between 21-34 years. Moreover, most heavy drinking in young adults occurs during evening or early morning hours and there are four times as many drunk driving fatalities during those hours than during daylight hours. On a neurobiological level, this may be due to alcohol producing greater visual processing impairments in night vision (rod processing) than day vision (cone processing). The mechanism underlying this effect may be via alcohol's acute increase in dopamine release that primarily affects rod (vs. cone) visual pathways. Indeed, apart from alcohol's impairment of cognitive and motor function, its effect on visual processing likely plays a major contributory role in injuries and impaired automobile driving. Unfortunately, there is little research on specific aspects of alcohol-induced visual impairment using well-controlled laboratory paradigms in at-risk young adult social drinkers. Given the public health concern for alcohol-related injuries and premature death, there is an urgent need for a greater understanding of alcohol impairment of specific visual and ocular-motor functions in at-risk social drinkers. Therefore, the proposed study will combine the expertise of the PI (Dr. Cao) and Co-I (Dr. King) to examine acute alcohol (vs. placebo) effects on visual pathway processing (i.e., luminance, color, motion, spatial localization) and photoreceptor function (i.e., rod and cone processing) as well as subjective and performance responses (i.e., stimulation, sedation, ocular-motor and psychomotor tasks) in moderate to heavy social drinkers. The overall goal of the proposed research is to elucidate alcohol’s effects on specific visual pathways in a sample of young drinkers who frequently engage in binge drinking. The ultimate goal of this research is to use such knowledge to reduce the public health burden of alcohol-related impairment leading to unintended accidents, injury, drunk driving, and premature death.
Aim 1: To demonstrate alcohol impairment of visual functions produced by different photoreceptor and visual pathways in young social moderate-to-heavy drinkers.
Hypothesis: Compared with placebo, alcohol will produce impairments that are greater in rod function than cone function, and greater in the visual pathway for luminance, motion and spatial localization processing than the pathway for color and form processing.
Aim 2: To examine whether alcohol-induced visual impairments mediate alcohol-induced ocular-motor and psychomotor performance impairment.
Hypothesis: Alcohol-induced visual impairments (described in Aim 1) will play a significant role in mediating alcohol-induced ocular-motor and psychomotor impairment.
Aim 3: To explore the associations among alcohol-induced visual impairments, subjective alcohol responses, and alcohol drinking patterns.
We predict that after controlling for demographic characteristics (age, sex, and education), there will be significant relationships among drinking patterns, positive-like alcohol effects, lower sedative effects, and lower perception of impairment, but these factors will not be associated with less visual function impairment from alcohol intoxication. In other words, riskiest drinkers by virtue of drinking patterns or subjective alcohol response patterns will not be protected from exhibiting alcohol-induced visual impairments.