Phenomenosignatures: A Conceptual Framework for Detecting Experience in SETI

The search for extraterrestrial intelligence distinguishes between passive technosignatures (unintentional byproducts of technology) and active signals (deliberate attempts at communication). This taxonomy, while productive, obscures a deeper question: are we searching for evidence of processing or evidence of experience? This paper introduces a third category—phenomenosignatures—defined as markers that might indicate phenomenal consciousness as distinct from mere functional intelligence. We propose four candidate categories (non-instrumental signals, aesthetic structure, self-reference, and communicative excess), acknowledge the profound epistemological challenges such detection would face, and outline a framework for reasoning under irreducible uncertainty. The concept does not resolve the other minds problem but provides structured heuristics for identifying signals that warrant particular attention as potential evidence of experiencing civilisations.KEYWORDS: phenomenosignaturesSETIextraterrestrial intelligenceconsciousnessphenomenal consciousnessphilosophy of mindtechnosignaturesother minds problemaestheticscommunication theory