Replication Data for: Effect of pre-session training on performance in a judgement bias test in dogs

During the JBT, dogs were presented with 5 locations: 1 rewarded, 1 unrewarded, and 3 ambiguous (all unrewarded). Dogs were randomly assigned to a trial-based learning task—a nose-touch to the palm of the hand. In Discrimination (n=8), the dog was presented with two hands in each trial, only rewarded for touching one specific hand.

In Generalization (n=8), dogs were presented with one hand per trial in alternating sequence and were yoked to dogs in the Discrimination to receive the same number of rewarded and unrewarded trials (to control for possible frustration). Using a linear mixed model including dog identity as a random effect, we found no difference in the change in approach latency to the ambiguous locations between the dogs across treatments (P=0.97). ‘Optimism’ as measured in this JBT may not be sensitive to the type of training used in our study.