| Baggage security screening of the subway is an important measurement to ensure the personal safety of passengers,and it is highly valued by the government and society.In China,baggage security-checking staff is carried out using X-ray equipment in complicated environment.Security screeners of the subway who have been exposed to high-intensity noise for a long time will distract and affect the level of emotional arousal,which may reduce the performance of X-ray security-checking staff and may even cause subway safety incidents.Based on this,systematic laboratory experiments were carried out to clarify the adverse effects of noise intensity on security screeners’ psychological state and cognitive performance,which is of great significance to the safety of subway operations.The paper designs an experimental scheme based on multi-objective visual search task,which has two dimensions: simple and complex.And simultaneously record the subject’s EEG signals and cognitive performance data during the experiment.Secondly,band-pass filter and independent component correlation algorithm are used for the preprocess of EEG signals.Frequency domain analysis based on the periodic graph method is used to extract spectral features between 0.5-50 Hz in order to assess attention and emotional arousal levels.Finally,the article analyzes the impact characteristics of sound pressure level on attention,arousal level and cognitive performance from the overall and time dimensions,and further explore the relationship between cognitive performance and attention and arousal level.The results indicate that there is a linear positive correlation between attention and test scores.When the sound pressure level is 66.3 dBA,it is conducive to concentration and reduce the false detection rate of security screeners,but when the sound pressure level is 76.7 dBA,the security screeners will be distracted and unresponsive.However,arousal level does not affect cognitive performance.When the task is simple,the sound pressure level of 87.7 dBA will be conducive to emotional arousal,but when the task is complex,the sound pressure level of 76.7 dBA is more conducive to emotional arousal.However,in tasks of different complexity,when the sound pressure level is 96.1 dBA,it is not conducive to emotional arousal.The experiment proves that it is scientific to use the distraction theory to explain the experimental cognitive results directly,but it is not reliable to use the arousal theory to explain the experimental cognitive results directly.It was also found that working time and task complexity will affect the subject’s sensitivity to the sound pressure level,which in turn affects changes in attention,arousal and cognitive performance.Combined with field research,the results show that arranging reasonable working hours and scientific reduction of the noise in the working environment can maximize work performance of security screeners.Moreover,this research is conducive to the management of performance of X-ray security screeners,but also improves human comfort. |
