## 4 Discussion
Trial type significantly altered the P200 amplitude in the frontal area, and changes in P200 amplitude are associated with early attentional allocation and active maintenance during working memory updating in the prefrontal cortex (PFC) [25], indicating the role of the executive control system in coordinating cognitive resources after an interruption occurs [33]. Under non-fatigued conditions, the P200 amplitude in the frontal region increased after both task and pause interruptions, suggesting a quick response of the facilitation system to task switching [34]. Notably, pause interruptions provide individuals with a brief \"cognitive buffer\", allowing the facilitation system to respond rapidly to task switching, resulting in a slightly higher P200 amplitude compared to simple task interruptions [35]. Under fatigue, when cognitive resources are nearly depleted, during pause interruptions, the inhibition system further reduces cognitive resource allocation, making it difficult for individuals to reallocate attention to the task. As a result, the P200 amplitude decreases, which is consistent with the behavioral data and aligns with previous research findings. Fatigue and trial type showed a significant interaction effect on P200 latency in the frontal region. Generally, P200 latency is a measure of stimulus classification speed, and is used as an indicator of neural efficiency and processing speed. Under fatigued conditions, increased P200 latency suggested a slight decrease in information processing speed [36]. Functionally, the frontal region is involved in generating attention-switching control signals, and shorter P200 latencies reflect stronger task switching abilities [37]. Task interruptions inherently involve switching between primary and interrupting tasks. Under non-fatigued conditions, P200 latency in the central and parietal regions decreased slightly after pause interruptions compared to pre-interruption trials, likely because participants could prepare and rehearse for the subsequent task during the pause. However, this preparatory advantage was not observed under fatigued conditions. The significant increase in post-interruption latency under fatigue aligns with the increase in RTs observed in the behavioral data. The increase in P200 amplitude and latency under fatigue indicates that the executive control system was actively adjusting strategies to address the challenges posed by fatigue,expending additional effort to maintain task stability and ACC. However, due to resource depletion and reduced efficiency of the facilitation system, behavioral performance further deteriorated. Fatigue did not significantly affect the mean amplitude of P300 overall, but its interaction with task type resulted in distinct neural response patterns under specific tasks. Fatigue significantly affected the peak latency of P300 in the frontal region, but not in other regions. The P300 component reflects attention reallocation to task-relevant events and their evaluation [38]. In the frontal region, fatigue, task type, and trial type demonstrated significant interaction effects for P300 amplitude. Under fatigued conditions, P300 amplitude decreased as the experiment progressed, following task and pause interruptions. Decreased frontal P300 amplitude indicates impaired executive control, with reduced capacity for working memory updating and attentional resource allocation [39]. Fatigue exacerbated these impairments [40], weakening inhibition functions and the ability to suppress irrelevant information [41], which is a typical top-down process requiring active executive control. This is consistent with the earlier findings. In the central region, P300 amplitude showed a significant interaction between fatigue and task type. Under fatigued conditions, P300 amplitude increased with experimental progression in both types of task interruptions. This suggests that as fatigue accumulated, the frontal region failed to allocate sufficient resources to meet task demands [42], leading to a decline in active control ability [43].