Aphasia as Language Ground State Destruction: Stroke-Induced Displacement from Self-Expression, the Isolation of Intact Thought, and Return Path Neuroplasticity

We apply the Displacement Framework to aphasia, formalizing the language ground state S°_lang as a three-component integrated manifold: comprehension, production, and communicative identity. Stroke-induced aphasia is displacement from this manifold — externally imposed D(ξ_lang) that severs access to S°_lang without necessarily disrupting the underlying thought the person seeks to express.

The aphasia taxonomy (Broca's, Wernicke's, global, anomic) is mapped to specific component failures within S°_lang. Nine formal propositions are derived covering: S°_lang as integrated comprehension-production-identity equilibrium, stroke as externally imposed D(ξ_lang), aphasia type as specific component failure, communicative identity disruption as the core displacement beyond language mechanics, social isolation and depression as secondary accumulated displacement from sustained communicative displacement, perilesional neuroplasticity as primary return path mechanism, constraint-induced aphasia therapy as forced return path traversal, AAC devices as prosthetic landscape bypass rather than S°_lang restoration, and communication partner training as landscape modification.

The framework explains why aphasia is not 'losing language' but losing access to a ground state, and why intact thought trapped behind damaged language produces its own distinctive secondary displacement cascade. The distinction between return path repair (speech-language therapy) and prosthetic bypass (AAC) has direct implications for treatment planning and goal-setting.