Geometric orientation in amphibians: Evolutionary conserved spatial navigation?

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

Donostia, San Sebastián

Congreso; XXV International Meeting of the Spanish Society for Comparative Psychology (SEPC); 2013

Spanish Society for Comparative Psychology (SEPC)

Although of crucial importance in vertebrate evolution, amphibians are rarely considered in studies of comparative cognition. Geometric orientation has been demonstrated in a variety of vertebrate species and appears dependent on the hippocampus. Using water as reward, we studied whether the terrestrial toad, Rhinella arenarum, is also capable of encoding geometric and feature information to navigate to a goal location. Experimental toads, partially dehydrated, were trained in either a white rectangular box (Geometry-only group) or in the same box with a removable colored panel (Geometry-Feature group) covering one wall. Four water containers were used, but only one (Geometry-Feature) or two in geometrically equivalent corners (Geometry-only) 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 or the location of the feature cue. Probe tests revealed that, under the experimental conditions used, toads can use both geometry and feature to locate a goal location, but geometry is more potent as a navigational cue. The results generally agree with findings from other vertebrates, and support the idea that at the behavioral level geometric orientation is a conserved feature shared by all vertebrates.