Effect Of Low Blood Alcohol Concentration On Human Optical Flow Processing

Alcohol,a widely used addictive substance,can have numerous systemic,cognitive and behavioral effects.Current studies have demonstrated that blood alcohol concentration conditions above 50mg/100 m L can cause impairment of many key functions that affect driving performance,but there is no definitive conclusion as to whether this stems from the effects of alcohol on the quality of visual processing or whether alcohol reduces the ability to respond to and control optical flow information.There is currently a gap in domestic research on low blood alcohol concentration conditions,and there are no relevant studies that can demonstrate how optical flow processing would be affected by alcohol.Based on this,and in conjunction with the current DUI standards in China,this study attempted to explore the effects of low blood alcohol concentrations of about20mg/100 m L-40mg/100 m L on drivers’ optical flow processing,and to distinguish the different effects of low alcohol concentration on visual processing and motor control through two different experimental tasks.In this study,a 2×2×2 mixed experimental design was used,in which 60 subjects were divided into 2 groups of 30 each,and all subjects were required to come to the laboratory twice,with an interval of about one week.The first experiment was the baseline condition,in which both groups of subjects started the experiment directly without drinking any liquid,and the second was the experimental condition,in which both groups of subjects were required to drink the specified experimental liquid(alcoholic beverage and placebo)before starting the experiment.In each experiment,the subjects were required to complete the same task under 2 speed conditions(30km/h and 60 km/h).Experiment 1 is a perceptual task in which the subjects are asked to make a judgment about the heading by the perceived optical flow information on the screen.Experiment 2 is a matching task,the subjects need to use the light flow information perceived in the screen and operate the steering wheel to control the viewpoint in the screen,so that they can match the instantaneous heading with the forward route.The results of the study demonstrated that the subjects’ pure visual processing performance was not significantly affected under low blood alcohol concentration conditions,but their visual processing-motion control circuit was significantly affected.This indicates that even low blood alcohol concentration impaired the subjects’ driving performance,and that this impairment was more significant under higher speed conditions(60km/h).Significance of the study: On the one hand,it reveals how low blood alcohol concentration affects visual processing and the corresponding visuomotor control processes,and on the other hand,it can raise the public’s awareness of safe driving and has some reference value for verifying the scientificity of the DUI standards implemented in China.