RIKEN team's path integral model unifies conscious and unconscious cognition

Researchers from RIKEN (Emori, Kondo, Iriki, and Khrennikov) have published a paper on arXiv (2607.24807) proposing a path integral model of cognition. They model goal-directed cognitive processes as imaginary-time evolution (ITE) under a projector Hamiltonian that rewards configurations consistent with a target concept. The paper establishes three main results: (1) ITE is equivalent to a double-bracket flow, making it a Riemannian gradient flow of a Hilbert–Schmidt cost with a unique minimum; (2) a Wick rotation converts this non-unitary descent into a unitary evolution that admits an exact discrete path-integral representation, where the oracle and diffusion projector act as potential and kinetic energy; (3) the continuum from unconscious to conscious processing is identified with the strength of unitary interaction between the cognitive system and a neural-environment probe.

In the weak-coupling Markovian limit, the model recovers the Gorini–Kossakowski–Sudarshan–Lindblad (GKSL) decoherence framework of Asano et al., while in the strong-coupling limit it yields projective, reportable fixation of an optimized state—the 'Aha!' moment of insight. Crucially, both regimes share the same ITE and path-integral structure; only the measurement-interaction strength varies. The Wick rotation thus serves as a re-description technique rather than a physical regime change. This work provides a mathematically rigorous unification of quantum decoherence and cognitive science.