MMReD: a Cross-Modal Benchmark for Dense Context Reasoning

ICLR 2026 Conference SubmissionAnonymous Authors
long contextreasoningLLMLVLMMLLMbenchmark
Abstract:

Despite recent advancements in extending context windows of large language models (LLMs) and large vision-language models (LVLMs), their ability to perform complex multi-modal reasoning over extended contexts remains critically limited. To underline this challenge, we present MMReD, a benchmark specifically designed to assess reasoning abilities within dense, information-rich scenarios where simple retrieval is not enough. Unlike traditional Needle-in-a-Haystack evaluations, MMReD challenges models to identify and interpret global patterns across entire contexts. Our benchmark comprises 24 tasks of varying complexity, ranging from standard passkey retrieval setups to those requiring selective or uniform attention to all context chunks. The evaluation reveals a consistent performance drop across all tested models -- including the most advanced LLMs, LVLMs, and architectures specializing in code and reasoning -- as the number of observations increases. Notably, even the leading reasoning-specialized models achieve 0% accuracy on certain tasks at the maximum context length of 128 observations. Conventional fine-tuning techniques, such as SFT and GRPO, also fail to generalize effectively to longer contexts. These observations reveal an inherent limitation in current model architectures, emphasizing the need for innovative approaches to enable competent dense context reasoning in multi-modal AI systems.

Disclaimer
This report is AI-GENERATED using Large Language Models and WisPaper (A scholar search engine). It analyzes academic papers' tasks and contributions against retrieved prior work. While this system identifies POTENTIAL overlaps and novel directions, ITS COVERAGE IS NOT EXHAUSTIVE AND JUDGMENTS ARE APPROXIMATE. These results are intended to assist human reviewers and SHOULD NOT be relied upon as a definitive verdict on novelty.
NOTE that some papers exist in multiple, slightly different versions (e.g., with different titles or URLs). The system may retrieve several versions of the same underlying work. The current automated pipeline does not reliably align or distinguish these cases, so human reviewers will need to disambiguate them manually.
If you have any questions, please contact: mingzhang23@m.fudan.edu.cn

Overview

Overall Novelty Assessment

The paper introduces MMReD, a benchmark designed to evaluate multi-modal reasoning over dense, information-rich contexts where global pattern identification is required rather than simple retrieval. Within the taxonomy, MMReD resides in the 'Dense Context Reasoning Benchmarks' leaf under 'Benchmarks and Evaluation for Long-Context Multi-Modal Tasks'. Notably, this leaf contains only one paper—MMReD itself—indicating that this specific focus on dense reasoning (requiring uniform or selective attention across all context chunks) represents a relatively sparse and underexplored direction within the broader evaluation landscape.

The taxonomy reveals that MMReD's parent branch contains two sibling leaves: 'Long-Form Video Understanding Benchmarks' (four papers including LongVideoBench and LVBench) and 'Multi-Modal Retrieval and Source Attribution' (three papers). These neighboring directions emphasize video-centric question answering or fragment localization tasks, whereas MMReD explicitly excludes simple retrieval scenarios. The broader 'Benchmarks and Evaluation' branch sits alongside architectural innovations (e.g., Extended Context Window Scaling, Efficient Processing Mechanisms) and reasoning strategies (e.g., Chain-of-Thought methods), suggesting MMReD addresses an evaluation gap that existing architectures and reasoning techniques have not yet adequately solved.

Among the three contributions analyzed, the benchmark itself (Contribution 1) examined ten candidates with zero refutations, suggesting limited prior work directly targeting dense context reasoning evaluation. Contribution 2, demonstrating model limitations, examined ten candidates and found four potentially overlapping studies—likely existing benchmarks or analyses revealing performance degradation at scale. Contribution 3, analyzing fine-tuning ineffectiveness, also examined ten candidates with no refutations. The total search scope of thirty candidates indicates a focused but not exhaustive literature review, meaning the novelty assessment reflects top-ranked semantic matches rather than comprehensive field coverage.

Given the limited search scope and MMReD's position as the sole occupant of its taxonomy leaf, the benchmark appears to address a genuine gap in evaluating dense reasoning capabilities. However, the presence of four potentially overlapping studies for the model limitation findings suggests that performance degradation in long contexts is a known phenomenon. The analysis does not capture whether MMReD's specific task designs (24 tasks requiring global pattern identification) represent a meaningful methodological advance over existing benchmarks, which would require deeper examination of task construction and evaluation protocols.

Taxonomy

Core-task Taxonomy Papers
50
3
Claimed Contributions
30
Contribution Candidate Papers Compared
4
Refutable Paper

Research Landscape Overview

Core task: multi-modal reasoning over extended dense contexts. This field addresses the challenge of integrating and reasoning over lengthy sequences of visual, textual, and other modalities—ranging from long videos to multi-page documents—where models must maintain coherence across thousands of tokens or frames. The taxonomy reflects a maturing landscape organized around several complementary directions. Long-Context Multi-Modal Understanding Architectures explore efficient encoding and memory mechanisms (e.g., Long-ViTA[4], Multimodal Long Memory[10]) to handle extended inputs without prohibitive computational costs. Reasoning and Inference Strategies develop methods such as chain-of-thought prompting and iterative refinement (GLM-4V Thinking[3], Thinking with Videos[8]) to improve logical consistency over dense contexts. Benchmarks and Evaluation, including works like LongVideoBench[2] and LVBench[26], provide standardized testbeds for assessing model capabilities on tasks requiring sustained attention and cross-modal integration. Meanwhile, Dense Video Captioning and Event Localization (Dense Event Captioning[21], MM-Narrator[25]) and Cross-Modal Alignment branches tackle the fine-grained temporal and semantic correspondence problems inherent in dense multi-modal data. Within this ecosystem, a particularly active line of work focuses on designing robust evaluation protocols that capture the nuances of long-context reasoning. MMReD[0] sits squarely in this space, contributing a benchmark specifically targeting dense context reasoning tasks. It shares thematic ground with other recent evaluation efforts such as LongInsightBench[48] and CFVBench[47], which similarly probe models' abilities to synthesize information across extended sequences. Compared to LongVideoBench[2], which emphasizes video-centric question answering, MMReD[0] appears to adopt a broader multi-modal stance, potentially incorporating diverse modalities beyond video alone. The interplay between architectural innovations (Long-ViTA[4], Visual Context Compression[9]) and rigorous benchmarking (MMReD[0], LVBench[26]) underscores an ongoing tension: as models grow more capable of ingesting longer contexts, the community must continually refine evaluation to distinguish genuine reasoning from superficial pattern matching. Open questions remain around scalability, generalization across domains, and the trade-offs between compression techniques and information retention.

Claimed Contributions

MMReD benchmark for dense context reasoning

The authors introduce MMReD, a new benchmark that evaluates multi-modal reasoning in dense contexts where models must identify and interpret global patterns across entire contexts, rather than performing simple retrieval. The benchmark comprises 24 tasks of varying complexity across sequence lengths from 1 to 128 observations.

10 retrieved papers
Demonstration of fundamental limitations in current models

The authors demonstrate that all tested models, including state-of-the-art LLMs and LVLMs, exhibit systematic performance degradation on dense context reasoning tasks as sequence length increases. Even leading reasoning-specialized models achieve 0% accuracy on certain tasks at maximum context length, revealing inherent architectural limitations.

10 retrieved papers
Can Refute
Analysis of fine-tuning ineffectiveness for dense reasoning

The authors show that standard fine-tuning approaches including supervised fine-tuning and GRPO do not enable models to generalize to longer contexts in dense reasoning scenarios. This finding emphasizes the need for innovative approaches beyond conventional training methods.

10 retrieved papers

Core Task Comparisons

Comparisons with papers in the same taxonomy category

Within the taxonomy built over the current TopK core-task papers, the original paper is assigned to a leaf with no direct siblings and no cousin branches under the same grandparent topic. In this retrieved landscape, it appears structurally isolated, which is one partial signal of novelty, but still constrained by search coverage and taxonomy granularity.

Contribution Analysis

Detailed comparisons for each claimed contribution

Contribution

MMReD benchmark for dense context reasoning

The authors introduce MMReD, a new benchmark that evaluates multi-modal reasoning in dense contexts where models must identify and interpret global patterns across entire contexts, rather than performing simple retrieval. The benchmark comprises 24 tasks of varying complexity across sequence lengths from 1 to 128 observations.

Contribution

Demonstration of fundamental limitations in current models

The authors demonstrate that all tested models, including state-of-the-art LLMs and LVLMs, exhibit systematic performance degradation on dense context reasoning tasks as sequence length increases. Even leading reasoning-specialized models achieve 0% accuracy on certain tasks at maximum context length, revealing inherent architectural limitations.

Contribution

Analysis of fine-tuning ineffectiveness for dense reasoning

The authors show that standard fine-tuning approaches including supervised fine-tuning and GRPO do not enable models to generalize to longer contexts in dense reasoning scenarios. This finding emphasizes the need for innovative approaches beyond conventional training methods.

MMReD: a Cross-Modal Benchmark for Dense Context Reasoning | Novelty Validation