My Dissertation is finally available online!
Due to some unforeseen circumstances, Texas State University never uploaded my dissertation online in 2025. I am glad I was able to get this sorted out and it is now finally online in the TXTS Digital Repository: https://digital.library.txst.edu/items/5162d292-7336-4f8f-a5a3-20c9530230bd
ABSTRACT: This dissertation project explores the cognitive and welfare aspects of touchscreen-based tasks in captive ruffed lemurs (Varecia spp.) using a custom-built apparatus, Subject-Mediated Automatic Remote Testing Apparatus 2 (SMARTA2). Across three interrelated studies, we assessed the utility of SMARTA2 in cognitive testing, SMARTA2’s effects on stress physiology and behavior, and the lemurs' willingness to engage in effortful tasks (contrafreeloading) using SMARTA2. In the first study, we developed and validated SMARTA2 as a low-cost, Android-based touchscreen system capable of administering visual discrimination tasks and contrafreeloading paradigms. In the second study, we measured salivary cortisol levels and recorded behaviors before and after cognitive testing to assess welfare impacts. Results showed cortisol increases after testing without corresponding behavioral signs of distress, suggesting that cognitive tasks were experienced as eustress and may serve as enrichment. In the third study, we employed a binary choice paradigm to test whether lemurs would contrafreeload, that is, opting to work for food using SMARTA2 instead of consuming freely available food. While most subjects showed no clear preference, two individuals consistently contrafreeloaded, and several exhibited increasing preference over time. These findings support the use of cognitive testing as behavioral enrichment in captive settings and demonstrate individual variability in motivation and enrichment value associated with touchscreen-based task. CITATION: Vagell, R. (2025). Touchscreen-based cognitive testing as enrichment in ruffed lemurs (Varecia spp.): SMARTA2 apparatus design, welfare implications, and contrafreeloading. [Doctoral dissertation, Texas State University].
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