Abstract:
Primate visual cortex exhibits key organizational principles: cortical magnification, eccentricity-dependent receptive field size and spatial frequency tuning as well as radial bias. We provide compelling evidence that these principles arise from the interplay of the non-uniform distribution of retinal ganglion cells, and a quasi-uniform convergence rate from the retina to the cortex. We show that convolutional neural networks outfitted with a retinal sampling layer, which resamples images according to retinal ganglion cell density, develop these organizational principles. Surprisingly, our results indicate that radial bias is spatial-frequency dependent and only manifests for high spatial frequencies. For low spatial frequencies, the bias shifts towards orthogonal orientations. These findings introduce a novel hypothesis about the origin of radial bias. Quasi-uniform convergence limits the range of spatial frequencies (in retinal space) that can be resolved, while retinal sampling determines the spatial frequency content throughout the retina.
摘要:
灵长类视觉皮层表现出关键的组织原理:皮层放大,与偏心率相关的感受野大小和空间频率调谐以及径向偏置。我们提供了令人信服的证据,证明这些原理是由于视网膜神经节细胞分布不均匀的相互作用而产生的。和从视网膜到皮质的准均匀收敛速度。我们证明了卷积神经网络配备了视网膜采样层,根据视网膜神经节细胞密度重新采样图像,制定这些组织原则。令人惊讶的是,我们的结果表明,径向偏差与空间频率有关,并且仅在高空间频率下表现出来。对于低空间频率,偏置向正交方向移动。这些发现引入了关于径向偏差起源的新假设。准均匀收敛限制了可以分辨的空间频率范围(在视网膜空间中),而视网膜采样确定整个视网膜的空间频率含量。