COMPUTATIONS ON METRIC MAPS IN MAMMALS - GETTING ORIENTED AND CHOOSING A MULTI-DESTINATION ROUTE

The capacity to construct a cognitive map is hypothesized to rest on t wo foundations: (1) dead reckoning (path integration); (2) the percept ion of the direction and distance of terrain features relative to the animal. A map may be constructed by combining these two sources of pos itional information, with the result that the positions of all terrain features are represented in the coordinate framework used for dead re ckoning. When animals need to become reoriented in a mapped space, res ults from rats and human toddlers indicate that they focus exclusively on the shape of the perceived environment, ignoring non-geometric fea tures such as surface colors. As a result, in a rectangular space, the y are misoriented half the time even when the two ends of the space di ffer strikingly in their appearance. In searching for a hidden object after becoming reoriented, both kinds of subjects search on the basis of the object's mapped position in the space rather than on the basis of its relationship to a goal sign (e.g. a distinctive container or ne arby marker), even though they have demonstrably noted the relationshi p between the goal and the goal sign. When choosing a multidestination foraging route, vervet monkeys look at least three destinations ahead , even though they are only capable of keeping a maximum of six destin ations in mind at once.