AI 中文总结
该研究提出将心理变量作为核心组件的MWM框架，实例化为MENTIS基线，实验证明显式建模心理状态对预测人类决策至关重要，推动世界建模从物理场景模拟转向心智模拟。
AI 中文摘要
世界模型为规划和行动提供了预测基础，但现有模型仅能回答物理层面的问题：对象是什么、位置在哪里，以及它将如何演化。然而人类行为由隐藏的心理状态驱动，心理状态包括个体的信念、欲望、意图、感受以及社会可接受性判断。因此，仅跟踪物理场景却不追踪各智能体对该场景的认知与信念的模型，会在外观正确的场景下预测出错误的行动。我们提出心理世界建模（Mental World Modeling, MWM），这是一个将心理变量作为世界模型核心组件而非事后解释的通用理论框架：MWM维护耦合的物理-心理世界状态，渲染目标特定的部分观测结果，并模拟候选行动如何共同更新这两个状态组件。我们将该框架实例化为MENTIS，这是一个无需训练且完全可解释的基线方法，将过程分解为状态解析、目标观测生成、行动分解、耦合物理与心理状态转移以及分支级价值评估。在一个手动构建的、经过质量控制的、涵盖文本、图像和有声视频故事的情境决策场景数据集上，对8种现代基于大型语言模型（LLM）的世界模型的实验表明，显式建模心理状态对于预测人类决策至关重要。更深入的分析进一步揭示了当前心理世界建模的瓶颈。我们期望MWM成为世界建模的下一阶段，从模拟物理场景转向模拟在其中行动的心智。
英文摘要
World models enable a predictive substrate for planning and action, yet existing formulations merely answer a physical question: what/where it is, and how will it evolve. Human behavior, however, is driven by hidden mental state (what a person believes, wants, intends, feels, and considers socially permissible), so a model that tracks the physical scene but not what each agent knows and believes about it predicts the wrong action for the right-looking scene. We formulate Mental World Modeling (MWM), a generic theoretical framework that makes mental variables core components of a world model rather than posthoc rationales: MWM aintains a coupled physical-mental world state, renders a target-specific partial observation, and simulates how candidate actions jointly update both components. We instantiate the framework in MENTIS, a training-free and fully inspectable baseline that decomposes the process into state parsing, target-observation generation, action decomposition, coupled physical and mental transition, and branch-level value evaluation. On a manually constructed, quality-controlled dataset of situated decision scenarios spanning text, image, and sounding-video stories, experiments with 8 modern LLM-based world models demonstrate that explicitly modeling the mental state is essential for predicting human decisions. Deeper analyses further expose the bottlenecks of current mental world modeling. We expect MWM as a next stage of world modeling, from simulating physical scenes to simulating the minds that act in them.
Commentsproject website: https://mental-world.github.io/
