Lyapunov Spectral Analysis of Speech Embedding Trajectories in Psychosis

• URL: http://arxiv.org/abs/2602.16273v1
• Date: Wed, 18 Feb 2026 08:46:46 GMT
• Title: Lyapunov Spectral Analysis of Speech Embedding Trajectories in Psychosis
• Abstract summary: We analyze speech embeddings from structured clinical interviews of psychotic patients and healthy controls.<n>Lyapunov exponent (LE) spectra are computed from word-level and answer-level embeddings.
• Score: 63.56564189749175
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We analyze speech embeddings from structured clinical interviews of psychotic patients and healthy controls by treating language production as a high-dimensional dynamical process. Lyapunov exponent (LE) spectra are computed from word-level and answer-level embeddings generated by two distinct large language models, allowing us to assess the stability of the conclusions with respect to different embedding presentations. Word-level embeddings exhibit uniformly contracting dynamics with no positive LE, while answer-level embeddings, in spite of the overall contraction, display a number of positive LEs and higher-dimensional attractors. The resulting LE spectra robustly separate psychotic from healthy speech, while differentiation within the psychotic group is not statistically significant overall, despite a tendency of the most severe cases to occupy distinct dynamical regimes. These findings indicate that nonlinear dynamical invariants of speech embeddings provide a physics-inspired probe of disordered cognition whose conclusions remain stable across embedding models.

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