by Raymond Vagell, PhD candidate at Texas State University
Cognitive research using nonhuman primates is common, yet little is known about the effects of cognitive research on the animals themselves. This project, funded by an AWI Refinement Research Award, sought to understand whether cognitive testing induced an arousal response in lemurs by measuring cortisol before and after a cognitive testing condition or a control condition.
Cortisol is secreted to regulate the body’s arousal response, and increased cortisol levels can be an indicator of stress or excitement. Here, the cortisol levels of seven black-and-white ruffed and red ruffed lemurs from the Duke Lemur Center were measured noninvasively by having the lemurs chew on cotton swabs covered in dried fig pulp. Samples were taken before and after interaction with a cognitive touchscreen, and before and after a control condition without a cognitive touchscreen.
We found that interaction with a cognitive touchscreen induced higher secretion of salivary cortisol. We cannot say, however, whether this increase in salivary cortisol is indicative of a positive response (excitement) or a negative response (stress). More research is needed in order to distinguish between these possibilities.