CoTZero: Annotation-Free Human-Like Vision Reasoning via Hierarchical Synthetic CoT

TL;DR

CoTZero introduces an annotation-free, hierarchical reasoning framework for vision-language models that synthesizes structured data and employs cognition-aligned training to improve human-like visual reasoning.

Contribution

It presents a novel dual-stage data synthesis and cognition-aligned training method that enhances VLMs' hierarchical reasoning without requiring annotations.

Findings

Achieves 83.33% F1 score on semantic inconsistency benchmark.

Improves interpretability and human-aligned reasoning in VLMs.

Each component significantly boosts reasoning coherence and generalization.

Abstract

Recent advances in vision-language models (VLMs) have markedly improved image-text alignment, yet they still fall short of human-like visual reasoning. A key limitation is that many VLMs rely on surface correlations rather than building logically coherent structured representations, which often leads to missed higher-level semantic structure and non-causal relational understanding, hindering compositional and verifiable reasoning. To address these limitations by introducing human models into the reasoning process, we propose CoTZero, an annotation-free paradigm with two components: (i) a dual-stage data synthesis approach and (ii) a cognition-aligned training method. In the first component, we draw inspiration from neurocognitive accounts of compositional productivity and global-to-local analysis. In the bottom-up stage, CoTZero extracts atomic visual primitives and incrementally composes them into diverse, structured question-reasoning forms. In the top-down stage, it enforces hierarchical reasoning by using coarse global structure to guide the interpretation of local details and causal relations. In the cognition-aligned training component, built on the synthesized CoT data, we introduce Cognitively Coherent Verifiable Rewards (CCVR) in Reinforcement Fine-Tuning (RFT) to further strengthen VLMs' hierarchical reasoning and generalization, providing stepwise feedback on reasoning coherence and factual correctness. Experiments show that CoTZero achieves an F1 score of 83.33 percent on our multi-level semantic inconsistency benchmark with lexical-perturbation negatives, across both in-domain and out-of-domain settings. Ablations confirm that each component contributes to more interpretable and human-aligned visual reasoning.