Building maps from maps in primary visual cortex.

Neurons in the visual system respond to more complex and holistic features at each new stage of processing. Often, these features are organized into continuous maps. Could there be a fundamental link between continuous maps and functional hierarchies? Here, we review recent studies regarding V1 maps providing some of the most noteworthy advances in our understanding of how and why maps exist. In particular, we focus on the common theme that some maps are inherited from the input of parallel pathways, which are then intimately linked to the emergence of new functional properties and their corresponding maps. These results on V1 maps may prove to be a unifying framework for hierarchical representations in the visual cortex.