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arXiv 2512.20249cs.LGcs.CVeess.IV

通过跨受体软ROI融合实现统一的多模态脑解码

Unified Multimodal Brain Decoding via Cross-Subject Soft-ROI Fusion

The University of Manchester, Manchester, UK(曼彻斯特大学)

Xuanyu Hu

AI总结:

本文提出BrainROI模型,通过软ROI融合和可解释提示优化,提升跨受体脑解码的泛化能力和描述质量,在NSD数据集上取得领先结果。

摘要:

多模态脑解码旨在从fMRI等脑活动信号中重建与视觉刺激一致的语义信息,并生成可读的自然语言描述。然而,多模态脑解码在跨受体泛化和可解释性方面仍面临关键挑战。我们提出BrainROI模型,在NSD数据集上的脑-描述评估中取得领先水平的结果。在跨受体设置下,与最新最先进的方法和代表性基线相比,BLEU-4和CIDEr等指标显示出明显提升。首先,为了解决功能脑拓扑在不同受体间的异质性,我们设计了新的fMRI编码器。我们使用多 atlas 软功能分区(soft-ROI)作为共享空间。我们将MINDLLM中的离散ROI拼接策略扩展为体素级门控融合机制(Voxel-gate)。我们还通过全局标签对齐确保一致的ROI映射,从而增强跨受体迁移能力。其次,为克服手动和黑箱提示方法在稳定性和透明性上的限制,我们引入了可解释的提示优化过程。在小样本闭环中,我们使用本地部署的Qwen模型迭代生成和选择可读的提示。此过程提高了提示设计的稳定性,并保留了可审计的优化轨迹。最后,在推理过程中我们施加参数化解码约束,进一步提高生成描述的稳定性和质量。

英文摘要:

Multimodal brain decoding aims to reconstruct semantic information that is consistent with visual stimuli from brain activity signals such as fMRI, and then generate readable natural language descriptions. However, multimodal brain decoding still faces key challenges in cross-subject generalization and interpretability. We propose a BrainROI model and achieve leading-level results in brain-captioning evaluation on the NSD dataset. Under the cross-subject setting, compared with recent state-of-the-art methods and representative baselines, metrics such as BLEU-4 and CIDEr show clear improvements. Firstly, to address the heterogeneity of functional brain topology across subjects, we design a new fMRI encoder. We use multi-atlas soft functional parcellations (soft-ROI) as a shared space. We extend the discrete ROI Concatenation strategy in MINDLLM to a voxel-wise gated fusion mechanism (Voxel-gate). We also ensure consistent ROI mapping through global label alignment, which enhances cross-subject transferability. Secondly, to overcome the limitations of manual and black-box prompting methods in stability and transparency, we introduce an interpretable prompt optimization process. In a small-sample closed loop, we use a locally deployed Qwen model to iteratively generate and select human-readable prompts. This process improves the stability of prompt design and preserves an auditable optimization trajectory. Finally, we impose parameterized decoding constraints during inference to further improve the stability and quality of the generated descriptions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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