LEARNING TO RECALIBRATE THE ROLE OF DEAD RECKONING AND VISUAL CUES INSPATIAL NAVIGATION

In Experiment 1, hamsters started from their permanent home at the per iphery of a circular arena and headed to a food source at the center. They then returned, fully laden with food, along a direct path to thei r home. On control trials, in which no manipulation takes place, visua l cues outside the arena and dead reckoning (i.e., updated internal re ferences generated during the outward journey to the food source) cont rolled the return journey. On experimental trials, the arena, with the hamster in its nest, was rotated by 90-degrees, putting dead reckonin g at variance with the distal visual environment. The animals were rew arded for going with dead reckoning. At first, they favored the distal cues, but later most of the subjects switched to using dead reckoning . Thus, hamsters are flexible enough to recalibrate the relative weigh t that they normally attribute to different sets of spatial cues. In E xperiment 2, the reliance on dead reckoning was greatly enhanced when a cue card at the nest entrance was rotated along with the arena, pitt ing one proximal cue plus dead reckoning against distal cues. Hence, d ead reckoning and external cues seem to reinforce each other through t heir mutual correlation.