UPDATING THE PATH INTEGRATOR THROUGH A VISUAL FIX

Mammals can navigate through path integration (dead reckoning) by upda ting their position on the basis of internal signals generated during locomotion, without using any external references. however, being open to cumulative errors, path integration remains functional over short excursions only, unless corrected by familiar landmarks. That such a c orrective process may occur was examined in golden hamsters during hoa rding excursions occurring in darkness, within a large open arena. The subjects proceeded from their peripheral nest to a feeding site on a platform. If the animals were rotated during food pouching, their subs equent homing behavior was disoriented, self-generated positional info rmation having been disrupted. By contrast, when the subjects were rot ated at the food source and then briefly presented with the familiar v isual environment, they returned homeward, albeit not very precisely. Thus, the animals may have taken an approximate positional fix, or res et their internal compass only.