DISTRACT: Degradation-Indexed Study of Textual Reference Across Competing Targets
Organizations: Ben-Gurion University of the Negev, Israel
Abstract
Vision-language trackers (VLTs) accept descriptions intended to assist tracking, but accepting text does not establish that its content changes tracking decisions, particularly as visual evidence deteriorates. We introduce DISTRACT, a matched-intervention benchmark that holds video, target, and distractor fixed while crossing four text priors with four image degradations along a controlled severity axis. We evaluate five VLTs on four datasets using behavioral contrasts, layerwise representation probes, and activation patching. Molmo2 and JointNLT exhibit directed text use. Some effects contract under degradation, whereas others show no significant endpoint change after multiplicity correction. UVLTrack, MMTrack, and DUTrack respond only weakly to changes in text semantics, with no directed behavioral effect surviving FDR correction in the tested settings. Model-internal analyses reveal that at decision-near states, correct-versus-conflicting text is decodable in Molmo2 and JointNLT but not in the other three systems. In the responsive models, decodability peaks at late states where replacement produces little behavioral change, whereas replacing selected earlier states redirects conflict-associated trajectories toward the target. Because matched-correct donors do not significantly outperform unrelated donors, these interventions identify earlier intervention-sensitive states without establishing target-specific semantic rescue. DISTRACT thus exposes when and where text affects tracking under degraded visual evidence.
Figures & tables
| Dataset | Characterization | Pairs | Seq. |
|---|---|---|---|
| MeViS | referring seg., masks | 120 | 120 |
| DanceTrack | dance MOT, similar look | 60 | 13 |
| SportsMOT | athlete MOT, fast motion | 30 | 19 |
| PersonPath22 | pedestrian MOT, crowded | 30 | 20 |
| Perturbation | Fixed schedule values, – |
|---|---|
| Blur, | |
| Noise, | |
| Pixelation, | |
| Compression, | no-op |
| Molmo2 | JointNLT | UVLTrack | MMTrack | DUTrack | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dataset | |||||||||||||||
| DanceTrack | |||||||||||||||
| SportsMOT | |||||||||||||||
| PersonPath22 | |||||||||||||||
| MeViS | |||||||||||||||
| Contraction level (of 4 perturbation ramps) | Cases (of 14) |
|---|---|
| 4/4 | 1 |
| 1–3/4 | 3 |
| 0/4 | 10 |
| Model | Decision-near stage | Text BA | 95% CI | |
|---|---|---|---|---|
| Molmo2 | final coord. query (L36) | [ , ] | ||
| JointNLT | late-fusion | [ , ] | ||
| UVLTrack | pre-box-head search | [ , ] | ||
| MMTrack | coord. decoder input | [ , ] | ||
| DUTrack | pre-CENTER-head visual | [ , ] |
| Perturbation | late vis. sep. | late fused-text BA | output assoc. |
|---|---|---|---|
| blur | [ ] | ||
| noise | [ ] | ||
| pixelation | [ ] | ||
| compression | [ ] |
Appendix figures & tables32 assets
Supplementary material from the paper’s appendix.
Appendix
| System | Native operation | Pinned artifact used | Source / download URL | License status |
|---|---|---|---|---|
| Molmo2 | 8B VLM; clean point plus native tracking prompt point trajectory | allenai/Molmo2-8B , revision e28fa285 | https://huggingface.co/allenai/Molmo2-8B https://github.com/allenai/molmo2 | Apache-2.0 |
| JointNLT | BERT text encoder and visual–language fusion; clean box box trajectory | commit 94b338e1 ; JointNLT_ep0300. pth.tar ; swin_b_ep300_track | https://github.com/lizhou-cs/JointNLT https://drive.google.com/drive/folders/ 1ZKBDhgXgV1GLSzFxw5fqpqd ZuX1hjfQe?usp=share_link | MIT |
| UVLTrack | Language-conditioned box tracker; clean box and raw expression box trajectory | commit 6ca34055 ; UVLTrack_ep0300. pth.tar (baseline-base) | https://github.com/OpenSpaceAI/UVLTrack https://drive.google.com/drive/folders/ 1UZTrGcL3YlxvNpHi0wKsO_s KsTYuYnFo?usp=sharing | MIT |
| MMTrack | Language-conditioned multimodal tracker; clean box and raw expression box trajectory | commit 4586b013 ; MMTrack_ep0150. pth.tar (baseline) | https://github.com/Azong-HQU/MMTrack https://drive.google.com/file/d/ 1kM8qxwJHJg4HuZNPPTMFZZTG EdtASVAf/view?usp=sharing | MIT |
| DUTrack | Description-conditioned box tracker; static external expression plus clean box box trajectory | commit 490d9985 ; DUTrack_ep0045. pth.tar ( dutrack_256_full ) | https://github.com/GXNU-ZhongLab/ DUTrack https://drive.google.com/drive/folders/ 1edieIddvSzy9219F4WShajv Y4UmkKJV4?usp=sharing | No license file in pinned repo |
| Dataset | Source media and annotations used | Access URL(s) | License / use terms |
|---|---|---|---|
| MeViS | 120 pairs from 120 source videos. Native human-written motion expressions and masks provide both text and geometry. Source media are obtained from the upstream release. | https://github.com/henghuiding/MeViS | Upstream data: CC BY-NC-SA 4.0 https://creativecommons. org/licenses/ by-nc-sa/4.0/ ; not redistributed here |
| DanceTrack | 60 pairs. DanceTrack provides source video and identities; Molmo2-VideoTrackEval provides human-written expressions and point/mask trajectories. | https://dancetrack.github.io/ https://huggingface.co/datasets/allenai/ Molmo2-VideoTrackEval | Source video: non-commercial research; DanceTrack notes that Internet-sourced media are not project property. Molmo2-VideoTrackEval expressions/masks/points: ODC-BY-1.0 |
| SportsMOT | 30 pairs. SportsMOT provides source video and identities; Molmo2-VideoTrackEval provides human-written expressions and point/mask trajectories. | https://github.com/MCG-NJU/SportsMOT https://huggingface.co/datasets/allenai/ Molmo2-VideoTrackEval | Source video: CC BY-NC 4.0 https://creativecommons. org/licenses/ by-nc/4.0/ Molmo2-VideoTrackEval expressions/masks/points: ODC-BY-1.0 |
| PersonPath22 | 30 pairs. PersonPath22 provides source video and identities; Molmo2-VideoTrackEval provides human-written expressions and point/mask trajectories. | https://github.com/amazon-science/ tracking-dataset https://huggingface.co/datasets/allenai/ Molmo2-VideoTrackEval | Source release: CC BY-NC 4.0; some externally sourced videos are not redistributed by the provider. Molmo2-VideoTrackEval expressions/masks/points: ODC-BY-1.0 |
| Dataset | Effect | Naive (selected) | IPW | Full pool |
|---|---|---|---|---|
| DanceTrack | ||||
| SportsMOT | ||||
| Condition | Molmo2 input after its fixed scaffold | Specialized trackers |
|---|---|---|
| Neutral | no appended identity description | object |
| Unrelated | “The target is: ” | |
| Correct | “The target is: ” | |
| Conflicting | “The target is: ” |
| System | Initialization | Text interface | Output | Reset safeguard |
|---|---|---|---|---|
| Molmo2 | clean target point | native point-tracking scaffold | point trajectory | fresh generation state |
| JointNLT | clean tight box | raw expression, native track mode | box trajectory | ROI queue, template features, tracker state |
| UVLTrack | clean tight box | raw expression | box trajectory | state, frame counter, score and output cache |
| MMTrack | clean tight box | raw expression | box trajectory | adapter/tracker and decode state |
| DUTrack | clean tight box | static external expression | box trajectory | dynamic description and tracker state |
| Perturbation | raw | ||||||
|---|---|---|---|---|---|---|---|
| Blur | 8 | 0 | 2 | 3 | 4 | 5 | 6 |
| Noise | 9 | 0 | 4 | 5 | 6 | 7 | 8 |
| Pixelation | 8 | 0 | 1 | 2 | 3 | 4 | 7 |
| Compression | 7 | 0 | 2 | 3 | 4 | 5 | 6 |
| Model | Dataset | Eff. | Blur | Noise | Pixel. | Compr. | |
|---|---|---|---|---|---|---|---|
| JointNLT | MeViS | +14.2 | |||||
| JointNLT | PersonPath22 | +26.9 | |||||
| Molmo2 | DanceTrack | +12.8 | -6.4 | ||||
| JointNLT | MeViS | +10.6 | -4.1 | ||||
| Molmo2 | DanceTrack | +25.3 | -21.4 | -16.0 | |||
| JointNLT | MeViS | +7.8 | -5.1 | -3.4 |
| Model | Dataset | Blur | Noise | Pixel. | Compr. | |
|---|---|---|---|---|---|---|
| JointNLT | MeViS | +9.2 | -1.6 | |||
| Molmo2 | DanceTrack | +14.1 | -7.6 | -6.1 | ||
| Molmo2 | MeViS | +5.6 | -4.4 | -4.8 | +2.3 | |
| Molmo2 | PersonPath22 | +11.3 | -12.6 | -11.8 | -11.9 | -3.0 |
| (pooled, 4 perturbations) | ||||||
|---|---|---|---|---|---|---|
| Model | other/absent | other/absent | ||||
| Molmo2 | 67.9% | 2.4% | 29.7% | 37.4% | 3.7% | 58.8% |
| JointNLT | 43.6% | 9.0% | 47.4% | 19.3% | 7.3% | 73.4% |
| UVLTrack | 64.4% | 6.1% | 29.5% | 27.4% | 7.6% | 65.0% |
| MMTrack | 62.9% | 6.4% | 30.7% | 24.2% | 7.0% | 68.8% |
| DUTrack | 68.1% | 4.8% | 27.1% | 33.2% | 6.6% | 60.2% |
| Model | Dataset | point | box-IoU | diff |
|---|---|---|---|---|
| UVLTrack | DanceTrack | |||
| UVLTrack | SportsMOT | |||
| UVLTrack | PersonPath22 | |||
| UVLTrack | MeViS | |||
| MMTrack | DanceTrack | |||