论文标题
早期视觉皮层中的自上而下推断灵感的分层变异自动编码器
Top-down inference in an early visual cortex inspired hierarchical Variational Autoencoder
论文作者
论文摘要
将视觉皮层中的计算解释为环境生成模型中的学习和推断,在神经科学和认知科学方面都得到了广泛的支持。但是,由于缺乏适当的工具来解决它,因此层次计算是视觉皮质处理的标志,这对于生成模型而言仍然是不透水的。在这里,我们利用了各种自动编码器(VAE)的进步,以研究早期的视觉皮层,并用稀疏的编码层次结构VAE进行了自然图像训练。我们设计的替代体系结构都随着两个潜在层VAE的生成和识别成分而变化。我们表明,在轻度电感偏见下,在初级和次级视觉皮层中发现的表示形式类似。重要的是,纹理样模式的非线性表示是对VAE的特定体系结构的高级潜在空间的稳定特性,让人联想到次级视觉皮层。我们表明,具有自上而下的处理组件的神经科学启发的识别模型的选择对于具有生成模型的两个计算签名至关重要:在均值和图像上插入图像之外,学习后部的高阶矩。高阶响应统计中的模式为神经科学提供了灵感,以解释响应相关性和机器学习,以通过后部更详细的表征评估学习的表示形式。
Interpreting computations in the visual cortex as learning and inference in a generative model of the environment has received wide support both in neuroscience and cognitive science. However, hierarchical computations, a hallmark of visual cortical processing, has remained impervious for generative models because of a lack of adequate tools to address it. Here we capitalize on advances in Variational Autoencoders (VAEs) to investigate the early visual cortex with sparse coding hierarchical VAEs trained on natural images. We design alternative architectures that vary both in terms of the generative and the recognition components of the two latent-layer VAE. We show that representations similar to the one found in the primary and secondary visual cortices naturally emerge under mild inductive biases. Importantly, a nonlinear representation for texture-like patterns is a stable property of the high-level latent space resistant to the specific architecture of the VAE, reminiscent of the secondary visual cortex. We show that a neuroscience-inspired choice of the recognition model, which features a top-down processing component is critical for two signatures of computations with generative models: learning higher order moments of the posterior beyond the mean and image inpainting. Patterns in higher order response statistics provide inspirations for neuroscience to interpret response correlations and for machine learning to evaluate the learned representations through more detailed characterization of the posterior.