In Experiment 1, the confidence rating was introduced after they completed their responses in order to test the retrospective metamemory judgments. After each response, a high-risk and a low-risk choice were provided to the monkeys. They could earn one token regardless of their accuracy if they choose the low-risk option. When they chose high-risk, they were rewarded with three tokens if their memory response was correct on that trial but lost three tokens if they made incorrect responses. Morgan and colleagues (2014) found a significant positive correlation between memory accuracy and risk choice in two rhesus monkeys. That is, they were more likely to select the high-risk option if they answered correctly in the working memory task but select the low-risk option if they were failed in the memory task.