A Study On The Causes Of Salient Distractor Decreasing The Quitting Threshold

In extremely low target-prevalence occasions,such as subway security inspection or tumor lesion detection,the inspectors need to make a "No" decision response as soon as possible to quit the searches which targets are difficult to find.The key factor on which this decision depends is the individual’s quitting threshold.Studies have demonstrated that an individual’s quitting threshold is affected by a variety of factors,such as the target prevalence and the search set.A recent pioneering study found that a salient distractor can also adjust the quitting threshold,that is,the presence of a salient distractor can decrease the quitting threshold in the target-absence condition,prompting individuals to quit the search earlier（Moher,2020）.Moher believes that the phenomenon named the distractor benefit,is due to the consumption of attention resources by distractors causing the reduction of the quitting threshold,but this assumption has not been experimentally verified.This study will further test whether resource consumption is the reason for the decreasing of the quitting threshold by controlling the degree of distraction salience.The primary purpose of experiment one is to repeat Moher’s（2020）to verify the reliability of the distractor benefit and the impact of long-term training on it.Experiment one is similar to Moher（2020）,except the number of trials is three times that it,which allows authors to observe the changes in benefits under long-term training.The results repeated Moher’s（2020）results,and find that the distractor benefit is not stable,but a changing phenomenon,including three stages: latent,emerging,and disappearing.Experiment two refers to the previous design（Liesefeld et al.,2017）,using a circular layout,and controls the degree of distractor’s salience by adjusting the inclination angle between the targets and background items,to adjust the level of allocated resources captured by the distractors.To achieve the purpose of exploring the relationship between the degree of distraction capture attention resources and the quitting threshold.The results found no distractor benefit in the two conditions,and we explain it due to the low salience degree of all items and fewer resources for capturing attention.To solve this issue,experiment three adjusts the layout to enhance the salience of the target and distractor,finding a significant distractor benefit observed in the high salient condition,but not in the low salient condition.Combining the three experiments’ results,this study concludes: First,the salient distractor consumes attention resources to adjust the level of the quitting threshold,which is a relatively stable phenomenon.Second,this phenomenon is regulated by attention resources.The more attention resources are captured by the distraction item,the greater the reduction of the threshold,producing the stronger the benefit.