Zero-PII Architecture: An Exploratory Structural Precondition for Safer Human-Machine Interaction in the Age of Cognitive Biomarkers

Every human-machine interaction leaves traces. In most contexts, these traces are manageable—a click, a page view, a purchase. In specific high-risk contexts—cognitive overload, fraud pressure, emotional vulnerability, AI companionship, healthcare AI, crisis decision-making—the traces are categorically different. They are cognitive and biological in character: reaction latencies, hesitation patterns, decision reversals under stress, emotional rhythms disclosed to relational machines. If retained and linked to identity across sessions, these traces constitute a cognitive biomarker profile—a map of when and how a specific person's judgment fails under pressure. This is not standard Personally Identifiable…