“…FAS can be also formulated as a domain adaptation/generalization problem in [28,34,60], where disentangled learning [41,75], adversarial learning [56], and meta learning [10,37,38,57,61] are adopt to improve the model's generalization capacity on unseen scenarios. Besides, several anomaly detection [1,17,36,46], zero-shot [40,51] and continuous learning [49,53] approaches are proposed for unknown PAs detection. Though the generalization capacity has been improved by those techniques, they are still restricted to labeled data in source domains.…”