CPS Lab 1@MMLow 2026: Hierarchical Multimodal Classification of Tamil Political Memes via Logit-Conditioned Stance-Target Prediction

Vishal Kumar, Anika Srivastava, Harshita Sharma, Nitisha Aggarwal, Geetika Jain Saxena, Amit Pundir, Sanjeev Singh


Abstract
Political memes have become an effective tool for online political communication and engagement. Their interpretation is particularly challenging in low-resource and code-mixed languages such as Tamil, where memes often include Tamil-English, use culturally relevant lexicon, incorporate political entities, and utilize references to prominent personalities and parties. This paper presents our submission to the MMLow shared task at AACL-IJCNLP 2026 on multi-level classification of Tamil political memes, which requires jointly predicting (i) a coarse-grained stance label (Support vs. Troll) and (ii) a fine-grained target label identifying whether the meme concerns a political party or a person. We proposed a lightweight hierarchical classifier built on frozen, pretrained multimodal encoders: images are represented using CLIP (ViT-B/32) and text using the multilingual BGE-M3 embedding model, with the two modalities combined via early, non-parametric concatenation fusion. A shared encoder feeds two prediction heads, where the target-identification head is explicitly conditioned on the stance head’s output logits via a gradient-detachment mechanism, allowing the model to respect the task’s label hierarchy without corrupting the coarse-level classifier’s gradients. To address pronounced class imbalance in both label levels, we applied balanced loss weighting at each level. On the test set of unlabeled data, our system achieved 3rd place, with macro-F1 scores of 0.856 for stance classification and 0.532 for target identification, yielding a final score of 0.694, indicating promising performance on the Tamil political meme classification problem.
Anthology ID:
2026.mmlow-main.11
Volume:
Proceedings of the Fifth Workshop on Multimodal Machine Learning in Low-resource Languages
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Rahul Ponnusamy, Prasanna Kumar Kumaresan, Saranya Rajiakodi, Premjith B, Shunmuga Priya MC, Abirami Murugappan, Jyothish Lal G, Sowmya V, Bharathi Raja Chakravarthi
Venues:
MMLow | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
97–102
Language:
URL:
https://aclanthology.org/2026.mmlow-main.11/
DOI:
Bibkey:
Cite (ACL):
Vishal Kumar, Anika Srivastava, Harshita Sharma, Nitisha Aggarwal, Geetika Jain Saxena, Amit Pundir, and Sanjeev Singh. 2026. CPS Lab 1@MMLow 2026: Hierarchical Multimodal Classification of Tamil Political Memes via Logit-Conditioned Stance-Target Prediction. In Proceedings of the Fifth Workshop on Multimodal Machine Learning in Low-resource Languages, pages 97–102, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
CPS Lab 1@MMLow 2026: Hierarchical Multimodal Classification of Tamil Political Memes via Logit-Conditioned Stance-Target Prediction (Kumar et al., MMLow 2026)
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https://aclanthology.org/2026.mmlow-main.11.pdf