A method for the investigation of those transformations under which the visual recognition of a given object is invariant

The theory is developed of a method for the investigation of those transformations which have the property that for a given object their action leaves visual recognition of the object invariant.The technique rests on a visual apparent movement effect known as phi-motion. Two assertions are arrived at. The first is that the existence of phi-motion between an object and transform implies the capacity of the visual system to effect a certain 1-parameter family of local transformations, and, in particular, implies the invariant recognition of the given object under the given transformation. The second is that it is possible to determine whether the observed 1-parameter family is part of a local 1-parameter group. A systematic investigatory program is built up on the basis of these two assertions. Application of this program is claimed to yield data upon the construction of the set of transformations “carried” by the visual system, and the nature of those paths in this set which are preferred by the system for execution.