The variability of orientation maps in cat visual cortex

In the visual cortex, orientation domains are arranged in complex patterns. In this study, we quantitatively analysed the variability of 2-deoxyglucose (2-DG) labelled patterns of orientation domains in area 17 of cat visual cortex. We calculated wavelengths, correlation-lengths, anisotropy parameters and band-parallelism parameters of patterns within the entire area 17 and analysed their statistical relationships. Our results indicate that these parameters are statistically independent. They describe independent aspects of the layout of orientation domains. Furthermore, a wavelet analysis showed that local wavelengths were rather constant, whereas the local orientation of band-like 2-DG domains varied across area 17. As a whole, these analyses identify sensitive quantitative indicators for the overall similarity of cortical orientation maps