Comparative cognition of spatial orientation

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All mobile species must orient, yet we know surprisingly little about how this process is achieved. My general objective is to study how animals orient within their environments. Spatial information can be classified as features or geometry. Features are objects (e.g., trees or rocks); whereas geometry is the metric relationship between objects or surfaces, (e.g., distances or directions). The relative reliance on these cues may be influenced by development. One testable hypothesis is that with maturity, cue encoding shifts from local cues to include more distant cues. To examine this hypothesis, I will rear birds in my laboratory and through tests which systematically alter their environment, examine how spatial cue use changes with development. Ecological pressures may also influence how spatial cues are used. In this case, the testable hypothesis is that animals which rely on their spatial memories for survival will encode stable cues that are robust to environmental change - i.e., geometry, whereas animals which rely on their spatial memory for short time periods will use cues that are very distinctive but not as stable - i.e., features. To test this hypothesis, I will investigate spatial cue use in three species of related birds. Two of these species are food-storing birds, each relying on their ability to store food to differing degrees, whereas the third species does not store food at all. By examining how these birds use spatial cues I can determine whether the ecological pressure of food-storing influences which spatial cues are encoded. Finally, birds allow for a unique opportunity to examine how each brain hemisphere encodes spatial cues. Birds lack a corpus callosum, the major source of interhemispheric connections in humans. This results in a "natural split-brain" like situation; visual information coming into the right eye is processed by the left hemisphere and vice versa for the left eye. Using a non-invasive eye capping technique, I will investigate how each hemisphere works independently, as well as how the two hemispheres work together to encode spatial cues. The novelty of my research program will take the field of spatial cognition in new directions, with implications for basic science, clinical neuropsychology and neuroscience.