| title | Sensorimotor Alignment: A Platonic Proxy for Embodied Policy Success |
|---|---|
| authors | Yunfei Xie, Howard H. Qian, Shiyi Lan, Kaiyu Hang, Chen Wei |
| date | 2026-10-23 |
| venue | arXiv (preprint, not peer reviewed) |
| id | arXiv:2610.31670 |
| affiliation | Rice University |
| upvotes | 38 (Hugging Face Daily Papers, 2026-11-01) |
| links | abs pdf hf code |
| primer | Vision-language-action models |
| abstract | Robot foundation models are typically evaluated through costly closed-loop rollouts, motivating low-cost offline proxies for model capability. The Platonic Representation Hypothesis (PRH) suggests that as representations improve, modalities such as vision and language converge toward a shared statistical model of reality. We ask whether motion trajectories form another such modality: as embodied models become more capable, should their sensory representations converge toward the structure of physical motion? To test this, we propose Sensorimotor Alignment (S^2), a training-free offline metric that measures how well a model's sensory representation aligns with the geometry of physical motion. We find that S^2 correlates positively with downstream robot task success across model families, making it a low-cost offline proxy for prioritizing models before closed-loop evaluation. S^2 can also identify promising vision-language model (VLM) backbones before costly fine-tuning into vision-language-action models (VLAs). Beyond this correlation, S^2 offers representation-level explanations for phenomena observed in VLAs and world action models (WAMs). With S^2, we extend PRH to robotics and make sensorimotor alignment measurable, offering a low-cost, representation-level view of robot foundation models that closed-loop success rates alone cannot reveal. |
cite
@misc{xie2026sensorimotor,
title={Sensorimotor Alignment: A Platonic Proxy for Embodied Policy Success},
author={Yunfei Xie and Howard H. Qian and Shiyi Lan and Kaiyu Hang and Chen Wei},
year={2026},
eprint={2610.31670},
archivePrefix={arXiv},
url={https://arxiv.org/abs/2610.31670}
}