Spatial Contiguity Facilitates Pavlovian Conditioning

The spatial contiguity between Pavlovian conditioned and unconditioned stimuli was examined using a chamber designed to prevent the usual confounding with delay of reinforcement. Eight ring doves were autoshaped in this apparatus. For half of the trials, a conditioned stimulus (CS) was presented 11 cm from the unconditioned stimulus (US); for the other trials, another CS was presented 74 cm away. After extended training, the stimuli were presented in nonreinforced test trials at a common, intermediate (42 cm) position. The CS that had been nearer the US was approached more closely, indicating that higher spatial contiguity facilitates Pavlovian conditioning. This research was funded by a grant from the National Science and Engineering Research Council to B. R. Moore, who also assisted in designing the apparatus. Thanks are extended to Tracy Taylor, Billy Schmidt, and B. R. Moore for suffering through drafts of this manuscript and providing helpful insights to improve the writing. Thanks are also extended to Bob Barnet for help in clarifying this paper and inspiring some of the ideas for future research.