The Influence Of Implicit Velocity Representation And Driving Experience On Hazard Perception

The effect of explicit velocity on representational momentum has been extensively studied,while the implicit velocity has received less attention due to the lack of overt signs.Although the implicit velocity is not easily to perceive,it can be presented by explicit features or feature changes of the object.The mechanism of implied velocity representation stems from the tendency of individual visual system to process and pick the most probable explanation for the observed visual information content and visual results.Referring to previous research paradigms,this study used color as an explicit cue of implicit velocity to represent the change of implicit velocity by changing the form and velocity of color change to explore the effects of implicit velocity representation and driving experience on hazard perception.Faces with neutral and fearful expressions were used as hazardous cues at different levels,with different grayscale(white-black)car models as moving objects.Using the implied motion paradigm,the relative relationship between the moving objects and the color changes,the direction of the object motion and different expressions presentation time were examined by four experiments to determine the influence on the participants with or without driving experience when judging the final position of the moving object,and displacement of moving object was taken as dependent variables.Study 1 involves two experiments.The facial expression of experiment 1a is presented at the same time as the first moving object,and it remains displayed until the last moving object disappears,presenting a total of 3750ms,which simulates a potentially dangerous situation.The experiment adopts a mixed design.The forms of color change(from dark to light,from light to dark,black unchanged,white unchanged),facial expression(neutral expression,fearful expression)are within-subject variables,and the driving experience is between subject variable.The facial expression of experiment 1b appeared in the last stimulus interval and remained present until the last moving object disappeared,presenting a total of 500ms to simulate the sudden dangerous situation.In experiment 1,the change forms of object color(from dark black to light black,from light black to dark black,black unchanged,white unchanged)represent the changes of implicit velocity.By controlling the time when facial expressions appear in experiment 1a and 1b to influence the degree of hazard,we investigated whether individuals with different driving experience would have different displacement.In experiment 2a and 2b,the velocity of color change was changed for further investigation.Similarly,study 2 involves two experiments.The duration of facial expression in experiment 2a is the same as that in experiment 1 a,and that in experiment 2b is the same as that in experiment 2a,that is,the difference between experiment a and experiment b lies in the duration of expression presentation.The experiment 2 also adopts a mixed design.The forms of color change(from dark to light,from light to dark),facial expression(neutral expression,fearful expression),and the speed of color change(fast,slow)are within-subject variables,and the driving experience is between subject variable.Results:(1).The colors of the moving objects affected the perception of the implicit velocity of the moving objects;the changes of object color and speed of objects,facial expressions and their presentation time constituted different levels of hazardous scenes,which affected the judgment of the final position of the object;(2).As a social cue,facial expression has an impact on the position judgment of the subjects and hazard perception.The representational momentum of neutral expression is greater than that of panic expression;(3).For potential hazard,compared with the non-driving participants,the experienced drivers showed less displacement,indicating higher hazard perception;when faced with emergent hazard,there were no significant difference in displacement between the two groups.Conclusion:(1).Color can be used as an explicit cue to characterize implicit velocity.The darker the color,the more energy and the higher the representational velocity could be perceived.(2).When color is combined with facial expression,traffic situations with different degrees of danger can be constructed.The dangerous situation induces higher level of hazard perception,so the representational momentum in dangerous situation is less than that in neutral situation.(3).Driving experience can effectively deal with potential hazard but its effectiveness would be diminished when dealing with emergent hazard.