title: Alcohol Intoxication Impairs Mesopic Rod and Cone Temporal Processing in Social Drinkers.
abstract: BACKGROUND
  Alcohol-related driving accidents and fatalities occur most frequently at nighttime and at dawn, that is, a mesopic lighting condition in which visual processing depends on both rod and cone photoreceptors. The temporal functions of the rod and cone pathways are critical for driving in this lighting condition. However, how alcohol influences the temporal functions in the rod and cone pathways at mesopic light levels is inconclusive. To address this, this study investigated whether an acute intoxicating dose of alcohol impairs rod- and/or cone-mediated critical fusion frequency (CFF; the lowest frequency of which an intermittent or flickering light stimulus is perceived as steady).
  
  
  METHODS
  In Experiment I, we measured the CFFs for 3 types of visual stimuli (rod stimulus alone, cone stimulus alone, and the mixture of both stimuli types), under 3 illuminant light levels (dim illuminance: 2 Td; low illuminance: 20 Td; and medium illuminance: 80 Td) in moderate-heavy social drinkers before and after they consumed an intoxicating dose of alcohol (0.8 g/kg) compared with a placebo beverage. In Experiment II, we examined whether the illuminance level (dark vs. light) of the visual area surrounding the test stimuli alters alcohol's effect on the temporal processing of rods and cones.
  
  
  RESULTS
  The results showed that compared with placebo, alcohol significantly reduced CFFs of all stimulus types at all illuminance levels. Furthermore, alcohol intoxication produced a larger impairment on rod-pathway-mediated CFFs under light versus dark surround.
  
  
  CONCLUSIONS
  These results indicate that alcohol intake slows down rod and cone-pathway-mediated temporal processing. Further research may elucidate whether this effect may play a role in alcohol-related injury and accidents, which often occur under low-light conditions.
authors.affiliation: Department of Ophthalmology & Visual Sciences, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Zhuang
authors.affiliation: Department of Ophthalmology & Visual Sciences, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Para
authors.initials: P
authors.lastname: Kang
authors.affiliation: Department of Psychiatry & Behavioral Neuroscience, University of Chicago, Chicago, Illinois.
authors.forename: Andrea
authors.initials: A
authors.lastname: King
authors.affiliation: Department of Ophthalmology & Visual Sciences, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Dingcai
authors.initials: D
authors.lastname: Cao
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology / Q000639:trends; D000435:Alcoholic Intoxication / Q000150:complications* / Q000453:epidemiology; D004311:Double-Blind Method; D000431:Ethanol / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects* / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
chemical_list: D000431:Ethanol
keywords: Alcohol; Critical Fusion Frequency (CFF); Mesopic Light Level; Rod and Cone Photoreceptors; Visual Temporal Processing