Johnson indicates that his analysis of "out" drew upon a 1981 doctoral dissertation by Susan Lindner in linguistics at UCSD under Ronald Langacker, and more generally by the theory of cognitive grammar put forth by him. For the force group of image schemas Johnson also drew on an early version of the force dynamic schemas put forth by Len Talmy, as used by linguists such as Eve Sweetser. Other influences include Max Wertheimer's gestalt structure theory and Kant's account of schemas in categorization, as well as studies in experimental psychology on the mental rotation of images.