MMA: Multimodal Memory Agent

Yihao Lu, Wanru Cheng, Zeyu Zhang, Hao Tang


Abstract
Long-horizon multimodal agents depend on external memory. However, similarity-based retrieval often surfaces stale, low-credibility, or conflicting items, which can trigger overconfident errors. We propose Multimodal Memory Agent (MMA), which assigns each retrieved memory item a dynamic reliability score by combining source credibility, temporal decay, and conflict-aware network consensus, and uses this signal to reweight evidence and abstain when support is insufficient. We also introduce MMA-Bench, a programmatically generated benchmark for belief dynamics with controlled speaker reliability and structured text–vision contradictions. Using this framework, we uncover the "Visual Placebo Effect," revealing how RAG-based agents inherit latent visual biases from foundation models. On FEVER, MMA matches baseline accuracy while reducing accuracy standard deviation by 35.2% and improving selective prediction utility; on LoCoMo, a safety-oriented configuration improves actionable accuracy and reduces wrong answers; on MMA-Bench, MMA reaches 41.18% Type-B accuracy in Vision mode, while the baseline collapses to 0.0% under the same protocol. Code is available at https://github.com/AIGeeksGroup/MMA.
Anthology ID:
2026.aacl-long.85
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1857–1873
Language:
URL:
https://aclanthology.org/2026.aacl-long.85/
DOI:
Bibkey:
Cite (ACL):
Yihao Lu, Wanru Cheng, Zeyu Zhang, and Hao Tang. 2026. MMA: Multimodal Memory Agent. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1857–1873, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
MMA: Multimodal Memory Agent (Lu et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.85.pdf