MARMOSET (CALLITHRIX-JACCHUS-JACCHUS) SPATIAL MEMORY IN A FORAGING TASK - WIN-STAY VERSUS WIN-SHIFT STRATEGIES

The spatial memory of common marmosets (Callithrix jacchus jacchus) was explored in 3 experiments with a simulated foraging task. In Experiment 1, individual monkeys foraged among 8 baited food sites. They appeared to use spatial memory to accurately avoid revisiting previously depleted sites. There was no difference in accuracy between the adult monkeys and a juvenile monkey tested on the same task. In Experiment 2, a win-stay paradigm was used. The adult monkey subject very accurately remembered locations that had previously contained food. The monkey tended to visit adjacent correct sites when retrieving food and thus minimized the total distance travelled. In Experiment 3, a win-shift paradigm was used with 2 adult monkeys. Although both monkeys performed at above-chance levels of accuracy on the win-shift task, they made many errors. These results suggest that marmosets may prefer tasks that require a win-stay strategy.