Martin, A. L., Franklin, A. N., Bloomsmith, M. A. 2010. Improving the efficiency of positive reinforcement training by testing food item preference. American Journal of Primatology 72(S1), 27. (33rd Meeting of the American Society of Primatologists Scientific Program, Abstract #6)

Positive reinforcement training relies on identifying an effective reinforcing consequence, often food, to be presented contingent on the performance of the desired behavior. Prior to training sessions, we used a multiple stimulus without replacement (MSWO) preference test to identify the food preference of 24 rhesus macaques (Macaca mulatta). The monkeys showed significant preferences among five food items [Friedman’s Test: χ2(4)=43.04, P<0.01]. Food rankings were moderately stable across individuals [Kendall’s W=0.49], and the stability of individuals’ preferences across time ranged from very low [Kendall’s W=0.04] to quite high [W=0.90]. To evaluate the effect of food preference on training, monkeys were given their high preference food, their low preference food, or a food chosen randomly from the five foods tested. An engagement score based on the animal’s compliance was recorded for each training session. Engagement during training of the first behavior differed significantly by food preference assignment [ANOVA: F(2, 23)=7.02, P<0.01], with those receiving their high preference food demonstrating higher levels of engagement than those given their low preference food. Engagement scores did not differ for later training tasks, perhaps indicating that food preference is most important early in the process. The MSWO technique was useful in determining food item preferences, and using the preference information improved the efficiency of training sessions