Memorization to Generalization: Emergence of Diffusion Models from Associative Memory
This work investigates the memory–generalization phase transition in diffusion models under varying training data scales. We propose a *correlational memory* perspective: training corresponds to memory encoding, while generation implements memory retrieval. We establish, for the first time, a theoretical connection between diffusion models and Hopfield networks, deriving necessary and sufficient conditions for the emergence of *spurious attractors*—hallucinated states—at the critical memory load threshold. Leveraging energy landscape analysis, dynamical systems modeling, and empirical validation on DDPM and DDIM, we confirm the universality of this phenomenon. Results show that models operate dominantly in memory mode under small-data regimes, shift toward generalization with large-scale data, and exhibit spurious attractors in the critical regime—unifying explanations for memory overload and implicit manifold learning. This work provides a cross-disciplinary theoretical framework and falsifiable predictions for understanding the intrinsic mechanisms of diffusion models.