关于视觉推理中的局部性与长度泛化
On Locality and Length Generalization in Visual Reasoning
摘要
人类视觉系统的显著特点在于,它通过一系列局部区域的视觉信息来接收视觉数据,而不是进行整体性的计算处理。这一特性使得人类视觉与当前大多数常用的计算机视觉模型截然不同——后者则是以全局方式一次性处理图像信息。因此,一个自然的问题就是:局部性、顺序性的视觉模型是否能在具有生物学上的合理性之外,还具备某种基本的计算优势呢?在这项研究中,我们从视觉状态跟踪和长度泛化这两个角度来探讨这个问题。受语言模型中长度泛化研究的影响,我们研究了那些需要整合图像中各个局部信息的简单视觉任务所训练的视觉模型的行为。实验结果表明,与语言模型类似,视觉模型也倾向于利用全局捷径来解决问题,因此无法在任务的长度或复杂性方面实现泛化能力。此外,基于严格局部感知的循环式视觉策略可以缓解这些问题,从而让模型能够在这些任务上实现泛化。我们的研究结果表明,局部注意力机制可能是实现稳健的泛化能力所必需的要素。
English Abstract
A striking feature of the human visual system is that it ingests visual information through a series of local foveated glimpses, rather than a single global computation. This makes human vision distinctly different from most popular computer vision models in use today, which input images globally and in a single shot. A natural question therefore is whether local, sequential vision models may provide any fundamental computational benefits in addition to being biologically more plausible than global models. In this work, we investigate this question from the perspective of visual state tracking and length generalization. Inspired by recent studies of length generalization in language models, we study the behavior of vision models trained on simple vision tasks that require the aggregation of local information across an image. Our experiments reveal that, similar to language models, vision models can learn to exploit global shortcuts and thereby fail to generalize over task length or complexity. We also show that recurrent vision policies based on strictly local perception can mitigate these failures, thereby allowing models to generalize on these tasks. Our results show that local attention may be an essential overlooked requirement for robust compositional generalization.