Cognitive approaches to mating decisions -- models and experiments in túngara frogs. Decisions about whether to mate with a particular individual -- whether the subject is a monogamous rodent or a promiscuous frog -- require an animal to begin by classifying stimuli. As a graduate student working with Drs. Michael J. Ryan and Walter Wilczynski, and as Smithsonian postdoctoral fellow working with Dr. A. Stanley Rand, I studied how mechanisms of signal recognition can shape mate choice. The work applied artificial neural network simulations inspired by cognitive psychology and linguistics, and signal detection theory appropriated from psychophysics, to mating decisions made by the túngara frog, Physalaemus pustulosus. We used neural network models to investigate how contemporary or historical selection for species recognition could shape current female preferences. More recently we used signal detection theory to assess the relationship between species recognition and mate choice, and how such decisions vary under different ecological conditions. This work combined theoretical, lab and field approaches to reproductive decisions - a strategy we plan to continue in our work on Alston's singing mouse. Social cognition in Alston's singing mouse. Alston's singing mouse, Scotinomys teguina, is a small, social rodent that lives in cloud-forests distributed from Panama into southern Mexico. Perhaps the most interesting of its traits is that it makes advertisement calls. Both males and females call, but males call more often. The calls seem to be recruiting conspecifics and do not seem to be particularly aggressive. Surprisingly little is known about the functions of calls or the mechanisms of call perception. We hope to develop this species as a new model for studying how genes coordinate the perceptual processes that function in species recognition and mate choice. This work will combine field studies in Monteverde, Costa Rica, with behavioral and neuroanatomical studies in the lab.