PIGEONS (COLUMBA-LIVIA) ENCODING OF GEOMETRIC AND FEATURAL PROPERTIESOF A SPATIAL ENVIRONMENT

Pigeons (Columba livia) searched for hidden food in a rectangular envi ronment constructed to eliminate external orientation cues. A feature group was initially trained with distinct features in each corner. A g eometric group was initially trained with no featural information. Tes ts revealed that both groups encoded the geometry of the apparatus. Th e geometric group was then retrained with features, and a series of te sts was administered to both groups. Transformation tests revealed tha t the groups differed in reliance on features versus geometry. Pigeons in the feature group followed the positive feature even when it was p laced in a geometrically incorrect corner, whereas pigeons in the geom etric group showed shared control by features and geometry. Both group s were able to use features in corners distant to the goal to orient t hemselves, and both groups relied more on the color than on the shape of the features.