Morgan et al. (2014) investigated whether rhesus macaques can make both retrospective and prospective metacognitive judgments on the same memory task. Risk choices were introduced to assess the monkey’s confidence about their memories. Two male rhesus monkeys ("Macaca mulatta") were trained in a computerized token economy task first in which they can accumulate tokens to exchange food rewards. Monkeys were presented with multiple images of common objects simultaneously and then a moving border appearing on the screen indicating the target. Immediately following the presentation, the target images and some distractors were shown in the test. During the training phase, monkeys received immediate feedback after they made responses. They can earn two tokens if they make correct choices but lost two tokens if they were wrong.