Exposing Cross-Modal Consistency for Fake News Detection in Short-Form Videos
Organizations: Mohamed bin Zayed University of Artificial Intelligence (MBZUAI) · Institute of Information Engineering, Chinese Academy of Sciences (CAS)
Abstract
Short-form video platforms are major channels for news but also fertile ground for multimodal misinformation where each modality appears plausible alone yet cross-modal relationships are subtly inconsistent, like mismatched visuals and captions. On two benchmark datasets, FakeSV (Chinese) and FakeTT (English), we observe a clear asymmetry: real videos exhibit high text-visual but moderate text-audio consistency, while fake videos show the opposite pattern. Moreover, a single global consistency score forms an interpretable axis along which fake probability and prediction errors vary smoothly. Motivated by these observations, we present MAGIC3 (Modal-Adversarial Gated Interaction and Consistency-Centric Classifier), a detector that explicitly models and exposes cross-tri-modal consistency signals at multiple granularities. MAGIC3 combines explicit pairwise and global consistency modeling with token- and frame-level consistency signals derived from cross-modal attention, incorporates multi-style LLM rewrites to obtain style-robust text representations, and employs an uncertainty-aware classifier for selective VLM routing. Using pre-extracted features, MAGIC3 consistently outperforms the strongest non-VLM baselines on FakeSV and FakeTT. While matching VLM-level accuracy, the two-stage system achieves 18-27x higher throughput and 93% VRAM savings, offering a strong cost-performance tradeoff.
Figures & tables
| Method | FakeSV | FakeTT | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Acc | macF1 | Real | Fake | Acc | macF1 | Real | Fake | |||||
| Pre | Rec | Pre | Rec | Pre | Rec | Pre | Rec | |||||
| Zero-shot VLMs | ||||||||||||
| GPT-4o-mini | 68.08 | 68.05 | 65.35 | 73.97 | 74.41 | 64.93 | 61.54 | 61.20 | 81.62 | 52.00 | 47.28 | 79.80 |
| GPT-4.1-mini | 70.30 | 70.25 | 68.12 | 73.53 | 73.10 | 68.21 | 49.16 | 48.54 | 77.42 | 48.00 | 37.50 | 71.40 |
| Qwen2.5-VL | 64.21 | 60.79 | 62.50 | 60.54 | 66.60 | 62.50 | 45.82 | 45.31 | 72.10 | 45.00 | 41.28 | 65.84 |
| Variant | Acc | F1 | AUC | |
|---|---|---|---|---|
| FakeSV | ||||
| MAGIC 3 (full) | 86.71 | 86.84 | 92.23 | |
| Consistency | w/o CMCG | 84.90 | 84.85 | 91.77 |
| w/o CFE | 85.69 | 85.61 | 92.30 | |
| w/o TCMI | 85.75 | 85.89 | 91.94 | |
| Fusion | w/o AARF | 84.49 | 84.71 | 91.43 |
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
| Category | Description and typical patterns |
|---|---|
| Entity & context inconsistency | Entities (persons, organizations, places) or contexts (e.g., country, city, venue) mentioned in text do not match those present in video or audio. A typical pattern is subtitles claiming “thousands protest in Paris” while the video shows a small rally in a different city. |
| Event-level semantic inconsistency | Modalities disagree on the core event: what happened, at what scale, or with which participants. For example, the caption claims “violent clashes erupt” but the video shows a peaceful gathering, or the audio describes a different incident. |
| Affective inconsistency | Sentiment or emotion conveyed by audio contradicts text or visual content, such as tragic subtitles overlaid on upbeat background music or calm narration over highly dramatic visuals. |
| Temporal audio–visual inconsistency | Audio and visual streams are misaligned in time, reused from different footage, or re-ordered. This includes dubbed videos, re-edited footage, or mis-timed sound effects. |
| Stylistic / pragmatic inconsistency | Rhetorical style, framing, or level of sensationalism in one modality is inconsistent with the others, e.g., a sensational subtitle for a relatively mundane video, or highly emotional text with neutral audio. |
| Component | Function | Consistency level | Role in findings / interpretability |
| Consistency Computation | |||
| CMCG | Computes pairwise consistency scores and global score | Pairwise global | Reveals asymmetric text–visual vs. text–audio patterns; defines the global consistency axis (Figures 3 – 4 ). |
| CFE | Derives token/frame-level consistency fields from cross-modal attention | Local (token / frame) | Localizes suspicious phrases or frames; supports heatmap visualization (Figure 6 ). |
| TCMI | Computes temporal audio–visual inconsistency score | Temporal | Detects coarse audio–visual synchronization mismatches common in repurposed videos. |
| Cross-Modal Fusion | |||
| AARF | Fuses original text with neutral/formal/sensational LLM rewrites via gated weights | Text-internal | Builds style-robust text embeddings; used to study style perturbation effects (Finding 4). |
| Dataset | Score | Real | Fake | -value |
|---|---|---|---|---|
| FakeSV | ||||
| FakeTT | ||||
| Dataset | Spear. | Pear. | |
|---|---|---|---|
| FakeSV | ( ) | ( ) | |
| FakeTT | ( ) | ( ) |
| bin | FakeSV rate | FakeTT rate |
|---|---|---|
| Lowest (Q1) | 0.93 | 0.83 |
| Q2 | 0.89 | 0.55 |
| Q3 | 0.76 | 0.17 |
| Q4 | 0.19 | 0.03 |
| Highest (Q5) | 0.05 | 0.07 |
| Dataset | Score | Real var | Fake var | |
| FakeSV | 0.0336 | 0.0815 | ||
| 0.0109 | 0.0148 | |||
| 0.0 | 0.0 | n.s. | ||
| FakeTT | 0.0194 | 0.0801 | ||
| 0.0081 | 0.0170 |
| Dataset | Routed Ratio | MAGIC 3 +VLM Acc | Routing Strategy |
|---|---|---|---|
| FakeSV | 25.1% | 90.93% | Entropy-based |
| FakeTT | 25.1% | 89.52% | Difficulty score |
| Statistic | FakeSV | FakeTT |
|---|---|---|
| Time range | 2017/10–2022/02 | 2019/05–2024/03 |
| Avg. duration (s) | 39.88 | 47.69 |
| # Fake videos | 1,810 | 1,172 |
| # Real videos | 1,814 | 819 |
| # Total | 3,624 | 1,991 |
| Hyperparameter | Value |
|---|---|
| Learning rate | |
| Batch size | 32 |
| Epochs | 50 |
| Warmup ratio | 0.1 |
| Hidden dimension | 256 |
| Attention heads (HMT) | 8 |
Fake News Detection
Fake news detection identifies false or misleading claims by analyzing content, context, evidence, and how information spreads.
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