Neural implementation of coarse-to-fine processing in V1 simple neurons

Coarse-to-fine processing has been observed in various areas of the visual cortex. For example, some receptive fields (RFs) of neurons in the primary visual cortex (V1) shrink spatially as time progresses. Such V1 neurons become more sensitive to higher spatial period stimulus in 20 ms. Furthermore, orientation selectivity in V1 also increases, that is, orientational coarse-to-fine processes. As described herein, we investigate the neural substances related to coarse-to-fine processing. We find that such coarse-to-fine processing corresponds to deblurring operations to achieve V1 neural output with spatially and orientationally higher resolutions. We show computationally that the short-range horizontal connections (SHCs) realize the deblurring operation.We simulate a V1 network model with SHCs based on the Sasaki model [1] (Sasaki and Satoh, 2009). The shrinking V1 receptive-field and increased orientational selectivity are caused by neural deblurring operations through SHCs. The model properties are qualitatively consistent with physiological data.