## 2 Materials and Methods
### Experimental Design  
(1) Experimental paradigm  
The experimental paradigm for this study was developed using E-Prime 3.0 (Psychological Software Tools (PST), Pittsburgh, PA, USA).To induce fatigue in participants, the Continuous Performance Task AX-CPT was employed [16]. This paradigm involves cue stimuli and probe stimuli, using 24 letters as materials, excluding \"K\" and \"Y\" due to their similarity to \"X\". Each trial presents four letters: the first is a red cue (only \"A\" is valid), the last is a red probe letter (only \"X\" is valid), and the middle two are random white distractor letters. The task includes four types of trials. A target trial is defined as A-distractor-distractor-X (70% probability). Three non-target trials (each with a 10% probability) are as follows: an invalid cue-distractor-distractor-valid probe, an invalid cue-distractor-distractor-invalid probe, and a valid cue-distractor-distractor-invalid probe. Each letter is displayed for 200 ms, with a 1000 ms inter-trial interval for responses. Participants press the \"f\" key for target trials and the \"j\" key for non-target trials. The interruption experimental task was designed based on the spatial 2-back working memory paradigm. Tunneling machine operators often need to respond to multiple equipment alarms and sudden environmental changes during their actual work. These task interruptions require them to quickly switch attention and allocate resources. The N-back paradigm, as a classic method for measuring working memory load [17], simulates the cognitive load encountered by tunnel drivers in their work. The 2-back task stimuli consisted of small black squares randomly appearing in one of the eight positions (excluding the center) of a 3 \(\times\) 3 grid against a white background. Each stimulus was displayed for 500 ms, with an interstimulus interval of 1500 ms [18]. Participants were required to compare the currently presented stimulus with the one presented two steps earlier, to determine whether they matched. Responses were made by pressing the \"f\" key for \"match\" and the \"j\" key for \"non-match\". The random location of each stimulus was treated as a \"target\" memory, requiring participants to maintain and retrieve these memories in the short term to make match decisions. During the execution of the primary 2-back task, an immediate interruption strategy [19] was employed to introduce interruption tasks, which disrupting the continuity of the main task. Two types of interruptions were designed: task interruptions and pause interruption. Task interruptions included two subtypes: simple and complex, illustrated in Figure 1. The simple task interruption involved arithmetic problems within 100, such as determining whether \"85-27 \(<\) 60\" was correct. The complex task interruptions involved arithmetic problems with mixed operations of multiplication, division, addition, and subtraction, such as judging whether \"8 \(\times\) (2 + 12) \(>\) 300\" was correct. Each task interruption trial was displayed for 2500 ms, with an inter-trial interval of 2000 ms. Pause interruption, on the other hand, required no active operation, but involved prolonged fixation. The pause duration was matched with the total duration of the arithmetic task interruptions, to facilitate comparative analysis of the impact of irrelevant information interference during interruptions on task performance and ERP components. Each interruption included twelve pre-interruption and two recovery trials. In total, there were 312 pre-interruption trials and 48 recovery trials under both task and pause interruption conditions. Before the formal experiment, participants were required to thoroughly practice the three task types (task interruption, pause interruption, and baseline non-interruption) to avoid learning effects during the formal experiment and ensure familiarity with all task scenarios. The formal experiment was divided into a fatigue phase and a non-fatigue phase, conducted on separate days in a randomized order.