Geometry and Local Feature Cues

MUZIO, R. N. SOTELO, M. I & BINGMAN, V. P.

Bogotá

Congreso; XVIIth Biannual Meeting of the International Society for Comparative Psychology (ISCP); 2014

International Society for Comparative Psychology

Although of crucial importance in vertebrate evolution, amphibians are rarely considered in studies of comparative cognition. Previously, we demonstrated that toads can use both geometry and a large boundary-feature cue to navigate, and that they prefer the former when locating a goal. Geometric navigation appeared to be dependent on the hippocampus, generally agreeing with findings in other vertebrate species. Using water as reward, we now studied spatial memory in the terrestrial toad, Rhinella arenarum, when geometric and feature information provided by local environmental cues could be used for goal navigation. Experimental toads, partially dehydrated, were trained in a white rectangular arena with one of each, four local features of different shape and color present at each corner of the arena. Four water containers, also located in the corners of the arena, were used, but only one had water accessible to the test animals. After learning to successfully locate the water reward, probe trials were carried out by changing the shape of the arena and removing or changing the location of the local-feature cues. Probe tests revealed that under the experimental conditions used, toads can use both geometry and local features to locate the goal, and that both sources are equally important for navigation. The results highlight again the importance of boundary geometry for goal navigation, and its seemingly conserved properties across vertebrates. However, in contrast to a large boundary-feature cue, local-feature cues seem to be equally potent in controlling the goal localization behavior of toads.