Gabriele Schino was awarded a Leakey Foundation research grant during our fall 2014 cycle for his project entitled “The emotional basis of primate reciprocity.” He and his collaborator Elsa Addessi are from the Institute for Cognitive Sciences and Technologies, National Research Council in Rome, Italy.
Earlier this year we featured a short summary of his team’s work on our blog. Click here to read the article. Now he has been kind enough to provide an update on their progress.
Our research addresses the emotional consequences of social interactions in capuchin monkeys using two different cognitive bias tests.
We are currently running our first experiment in which we carry out judgment bias tests in order to evaluate the emotional consequences of receiving grooming (a common cooperative behavior). We test monkeys under two different conditions: after receiving grooming and in the absence of received grooming. We have almost completed data collection for this experiment, and we will soon start data analysis.
Figure 1 shows the experimental apparatus used in Experiment 1, and attached is a video of a subject during an “ambiguous trial”.
Figure: During the judgment bias test, each capuchin monkey is presented with a visual conditional discrimination task. A striped rectangle acts as a discriminative stimulus, and monkeys are trained to choose one of two differently colored cups when the striped rectangle is nearby. The magnitude of the reward differs between conditions (when near the striped rectangle, the white cup yields one food item, while the black cup yields two food items; the “wrong” cup is always unrewarded). Once the monkeys can reliably make the correct choice under both conditions, they are tested under a third, “ambiguous” condition (the rectangle is placed midway between the two cups). Their choice reflects their “optimistic” or “pessimistic” interpretation of the ambiguous stimulus.
In our second experiment, we will run attention bias tests in order to evaluate the emotional consequences of receiving aggression.
We have started with the preliminary work needed to run Experiment 2. We have completed the metal work needed in our experimental cages, and are at the moment building the experimental apparatus. We have also started training some of the monkeys to enter the experimental cages (several of our subjects are in fact already trained because of previous experiments run in our lab).
Summarizing, our work is proceeding as planned, with no unexpected problems. At this stage, we have no results to report.