The term is most often found in specialised works on psychology, neurobiology, and memory, though it was used in the same general way at least as early as the first half of the nineteenth century in works on rhetoric, logic, and philosophy. John O'Keefe and Lynn Nadel refer to:'the method of loci', an imaginal technique known to the ancient Greeks and Romans and described by Yates (1966) in her book "The Art of Memory" as well as by Luria (1969). In this technique the subject memorizes the layout of some building, or the arrangement of shops on a street, or any geographical entity which is composed of a number of discrete loci. When desiring to remember a set of items the subject 'walks' through these loci in their imagination and commits an item to each one by forming an image between the item and any feature of that locus. Retrieval of items is achieved by 'walking' through the loci, allowing the latter to activate the desired items. The efficacy of this technique has been well established (Ross and Lawrence 1968, Crovitz 1969, 1971, Briggs, Hawkins and Crovitz 1970, Lea 1975), as is the minimal interference seen with its use.