Spatial Learning: Blocking and Overshadowing between visual cues on the toad Bufo arenarum.

DANERI, M.F.; CASANAVE E.B.; MUZIO, R.N.

Buenos Aires, Argentina, 9 al 11/10

Congreso; 14th Biennial Meeting of the International Society for Comparative Psychology-; 2008

International Society for Comparative Psychology

Spatial learning allows amphibia, as well as other vertebrates, to localize shelter and food, remember this information and return to those places months later. Now we are analyzing the biological mechanisms that rule this learning, looking for common patterns with other vertebrates, potentially present in a common ancestor. The objective of this work is to determine if the blocking and overshadowing effects, well documented in mammals and birds, are present during spatial learning in amphibia (common toad Bufo arenarum). Two experiments were conducted where animals were trained to localize a reinforcement (water) using visual cues placed on the wall of an open field. On the first experiment we observed that the presence of a second visual cue can cause animals to use less a first one than they would have used if trained on it alone (overshadowing). On the second one a blocking effect was observed, the prior presentation of one element of a compounded visual cue reduces or blocks the learning about the second component of the cue. This results are demonstrating that blocking and overshadowing are generalized basic phenomena present in a wide variety of vertebrates, including mammals, birds and amphibians.