My interests within cognition are fuzzy at this point, but I hope to incorporate spatial cognition and visualization in my research. I have tentative plans to study cognitive ecology of glossophagine bats (and the flowers they forage from) in York Winter's lab at the University of Bielefeld.

With Jody Lewis (who is now at UW Stevens Point), I am currently running a study involving Clark's Nutcrackers. We are testing whether interference involving contextual information (background spatial patterns) affects memory of cache locations. We are testing whether interference influences nutcrackers’ memory of spatial lists. Birds are tested in an open room (photo below) in which there are about 150 holes drilled in the floor. Each hole contains a sand filled cup in which a seed can be buried. Nutcrackers are first given a serial list of five locations, by allowing them to probe for seeds in five different holes. After a retention interval, nutcrackers are tested on their memory of each of those five locations. For each correct, and seeded location, a cluster of possible holes is opened and the bird is allowed to probe for the seed. Error is measured by how many tries it takes the bird to locate the seed.

We tested interference effects by giving nutcrackers either one or two lists a day. The interfering list either came before (proactive) the target information, or after (retroactive). Birds perform more poorly when they are given two lists a day versus one. Furthermore, performance was the worst when one of the incorrect alternatives in the choice test was a rewarded location from the interfering list. We are the first to demonstrate that although nutcrackers have incredible memory performance they are still susceptible to the effects of proactive and retroactive interference. These findings have important implications for understanding what specific cognitive processes are involved in the evolution of food storing.

Furthermore, previous laboratory experiments have found that nutcrackers are extremely accurate in locating their caches, however, they still make many errors by revisiting depleted cache sites. Our results suggest that Clark’s nutcrackers are susceptible to interference from depleted locations when recalling spatial information. We are hoping that these controlled experiments will suggest reasons for why nutcrackers tend to revisit caches in the laboratory and how they possibly minimize this type of interference in their natural environment.