Attentional Selection and Allocation to Alarm Signals in Complex Environments: The New Electrophysiological Evidence

Background/Objectives: This study explore attentional selection and allocation during alarm signal processing in complex environments. Methods: Adopting the dual-task paradigm combining Visual Alarm Task and Main Task with EEG recording, a total of 120 participants were recruited into two experiments with the different presentation order of two tasks. Results: Results showed that lateral targets in the Visual Alarm Task induced significant N2 posterior contralateral (N2pc, 200-250 ms) and sustained posterior contralateral negativity (SPCN, 250-500/450 ms) in the parieto-occipital region. N2pc correlated with alarm detection speed and Search Score (the individual search ability), while SPCN correlated with the Subjective Workload Analysis Technique (SWAT) Score. When the Main Task preceded the Visual Alarm Task, the Main Task load modulated attentional selection and allocation-the load of the Main Task moderated the effect of subsequent alarm-elicited sustained negativity on the SWAT Score. Conclusions: These findings revealed the functional separation of attentional processes in the cognitive control of alarm signals in complex environments. The study provides new electrophysiological evidence for multi-task attentional allocation and implications for alarm design in high-risk systems.