Data from: The use of preferred social stimuli as rewards for rhesus macaques in behavioural neuroscience

Macaques are often motivated to perform in neuroscientific experiments by
implementing fluid restriction protocols. Daily access to water is
controlled and the monkeys are rewarded with droplets of fluid for
performing correct trials in the laboratory. Although these protocols are
widely used and highly effective, it is important from a 3Rs perspective
to investigate refinements that may help to lessen the severity of the
fluid restriction applied. We assessed the use of social stimuli (images
of conspecifics) as rewards for four rhesus macaques performing simple
cognitive tasks. We found that individual preferences for images of male
faces, female perinea and control stimuli could be identified in each
monkey. However, using preferred images did not translate into effective
motivators on a trial-by-trial basis: animals preferred fluid rewards,
even when fluid restriction was relaxed. There was no difference in the
monkeys’ performance of a task when using greyscale versus colour images.
Based on our findings, we cannot recommend the use of social stimuli, in
this form, as a refinement to current fluid restriction protocols. We
discuss the potential alternatives and possibilities for future research.