This study aims to analyze the electroencephalographic power spectrum and connectivity during unresponsive states induced by propofol, esketamine and dexmedetomidine, respectively. It intends to explore the macro neural mechanisms underlying anesthetic unresponsiveness, so as to further elucidate the mechanisms by which anesthetics induce loss and recovery of consciousness. In addition, this study will identify neural biomarkers under general anesthesia for monitoring patients' actual intraoperative consciousness status. The findings will facilitate the development of monitoring indicators and devices reflecting intraoperative consciousness during general anesthesia, enabling more accurate assessment of patients' intraoperative consciousness status.

Inclusion Criteria:

• Patients scheduled for elective non-cardiac surgery;
• American Society of Anesthesiologists (ASA) physical status classification I-II;
• Aged 18 to 65 years, regardless of gender;
• Body mass index (BMI) greater than 18 kg/m² and no more than 31 kg/m²;
• Written informed consent voluntarily signed by the patient or legal authorized representative for participation in this study.

Exclusion Criteria:

Subjects meeting any one of the following items will be excluded from this study:

• Presence of severe cardiovascular diseases or hepatic and renal insufficiency;
• Hearing impairment;
• History of psychiatric disorders or communication disorders;
• Anticipated difficult airway;
• Pregnant or lactating women;
• History of allergic reaction or contraindication to any of the three anesthetic drugs used in this trial;
• Participation in other clinical trials within the past 3 months.

De-identified individual participant data including demographic characteristics, baseline clinical information, perioperative vital sign data, anesthesia induction and recovery related data, EEG analysis results, and adverse event records will be shared.

Available starting from 1 year after study completion, and will be kept available for at least 5 years thereafter.

Only qualified researchers conducting independent academic research may access the de-identified IPD and supporting study documents, including study protocol, statistical analysis plan, and clinical research raw data. Access can be requested by submitting a formal research application to the corresponding author via official email, and access will be granted after formal review and approval.