Yeap  argued that an important basis for computing a cognitive map is the ability to compute and recognise local environments. Although he has demonstrated how such local environments could be used to construct a raw cognitive map, he failed to produce an adequate algorithm for computing them. In this paper, a detailed study of this problem is presented. We argue that although each local environment computed forms a natural basis for constructing a raw cognitive map, it is not computed primarily to do so. Instead, it is computed for one's immediate needs (such as hunting a prey or escaping from danger). This change in perspective argues for a very different cognitive mapping process, namely one that computes local environments as the individual moves through the environment but these representations are not necessarily used to construct a raw map. The individual does not do so until there is evidence that it is going to stay. Consequently this simplifies the algorithm fo..