1. The Relationship Between Geometric Shape and Slope for the Representation of a Goal Location in Pigeons (Columba livia) Daniele Nardi Bowling Green State University

2. Platform surrounded by curtains Feeder Arena 50cm Pigeon Floor Platform 20º Arena Top viewLateral view Apparatus

3. Arena on a flat surfaceArena on a slope (20º) Apparatus

4. Acquisition * Slope-related cues added a considerably salient orienting cue to the geometric shape of the arena → The task was significantly easier on a slope Possible factors: shape of the arena, slope inclination. * Experiment 1

5. Geometry test Training UPHILL DOWNHILL Goal Mirror Image NearFar Mirror Image NearFar FLAT Geom correct Subjects in the slope condition encoded geometric shape just like subjects in the flat condition. Training on a slope did not prevent learning geometric shape information. Experiment 1 *

6. Training UPHILL DOWNHILL Goal Mirror Image NearFar Conflict test UPHILL DOWNHILL Slope correct Geom correct Mirror Image Conflict test Pigeons encoded shape geometry but they were primarily relying on a slope-based representation to solve the task. Possible factors affecting the salience of geometry/slope: slope inclination, arena shape. Two modular output representations in guiding behavior Cheng & Newcombe, 2005 Experiment 1 * Other

7. FLAT Mirror Image NearFar Geom correct Geometry test uphill downhill uphill downhill flat FLAT CONDITION N = 5 SLOPE-HORIZONTAL CONDITION N = 5 SLOPE-VERTICAL CONDITION N = 5 GEOMTERY + SLOPE Experiment 2 Goal 2: test if the salience of vertical information influences geometric shape learning GEOMETRY

8. Experiment 3 Rotation test Pigeons do not generalize the task to a novel orientation (replication of Kelly & Spetch, 2004) Systematic error to the mirror image corner… Why? Rotation test The novel orientation is COUNTERBALANCED * Training uphill downhill uphill downhill uphill downhill uphill downhill Geometric correct Mirror image Near Far

9. CONCLUSIONS Salience of slope information - first study showing that birds can locate a goal using a slope gradient - redundant multimodal sensory activations - implications against the primacy of geometry for navigation - implications against view-based strategy for solving geometric tasks Lack of cue competition between slope and geometric learning - many indications of an independent learning of geometry from feature cues - here geometry is not overshadowed by a cue that is more salient - new evidence in support of the “geometric module” Interactions between two spatial cues can go beyond overshadowing and can produce unexpected effects – lack of generalization. Study of associative learning applied to spatial memory should not be confined to the “usual” spatial cues.