What if...?: Thinking Counterfactual Keywords Helps to Mitigate Hallucination in Large Multi-modal Models
Junho Kim, Yeon Ju Kim, Yong Man Ro
TL;DR
This work tackles hallucination in large multi-modal models by injecting counterfactual thinking via self-generated keywords (Counterfactual Inception). It achieves this without parameter updates, using a Plausibility Verification Process (PVP) to filter keywords and condition responses on plausible yet alternative contexts. Across both discriminative and generative benchmarks on open-source and proprietary LMMs, the approach reduces hallucinations and improves grounding to true visual clues while enabling broader contextual understanding. The method thus offers a scalable, training-free mitigation for cross-modal reasoning in real-world deployments.
Abstract
This paper presents a way of enhancing the reliability of Large Multi-modal Models (LMMs) in addressing hallucination, where the models generate cross-modal inconsistent responses. Without additional training, we propose Counterfactual Inception, a novel method that implants counterfactual thinking into LMMs using self-generated counterfactual keywords. Our method is grounded in the concept of counterfactual thinking, a cognitive process where human considers alternative realities, enabling more extensive context exploration. Bridging the human cognition mechanism into LMMs, we aim for the models to engage with and generate responses that span a wider contextual scene understanding, mitigating hallucinatory outputs. We further introduce Plausibility Verification Process (PVP), a simple yet robust keyword constraint that effectively filters out sub-optimal keywords to enable the consistent triggering of counterfactual thinking in the model responses. Comprehensive analyses across various LMMs, including both open-source and proprietary models, corroborate that counterfactual thinking significantly reduces hallucination and helps to broaden contextual understanding based on true visual clues.
