Cognitive Fusion: Towards a Symbiotic Intelligence Beyond Tools

This preprint proposes Cognitive Fusion as a conceptual framework for understanding sustained human–AI interaction beyond instrumental tool use. It argues that high-frequency collaboration with large language models (LLMs) constitutes an ontological shift in the cognitive unit: from a human-only agent supported by external tools to a symbiotic mental unit (SMU), where cognition is co-constituted across human and AI. The paper introduces a stratified model of the symbiotic interface, describing four cognitive layers (semantic, contextual, structural, and meta-cognitive) through which human thought becomes increasingly coupled with AI-mediated organization, reflection, and tension modeling. Methodologically, the work is primarily a conceptual framework supported by autoethnographic evidence, including high-frequency interaction logs as empirical correlates. Rather than claiming a complete model of mind, this study offers a pragmatic vocabulary for describing a new mode of cognition emerging in everyday AI use, and outlines implications for agency, cognitive offloading, and the future of human–AI co-evolution.