This work indicates that primate visual cortex orientation column
structure is best understood in the context of other `ordered
continuous media' (e.g. liquid He3, cholesteric liquid crystals,
random optical phase maps, to name only a few) in which an order
parameter (orientation in this case) is mapped to a physical space,
and in which the topological properties of the mapping determine the
observable regularities of the system. We also point out that these
methods may well be applied to a variety of other cortical map systems
which admit an `order parameter', i,e. for which each cortical
position is assigned a continuous stimulus value