Rhesus monkeys (Macaca mulatta) adaptively adjust information seeking in response to information accumulated

Metacognition consists of monitoring and control processes. Monitoring has been inferred when nonhumans use a "decline test" response to selectively escape difficult test trials. Cognitive control has been inferred from selective information-seeking behavior by nonhumans ignorant of needed knowledge. Here we describe a computerized paradigm that extends previous work and assesses dynamic interactions between monitoring and control. Monkeys classified images as containing birds, fish, flowers, or people. To-be-classified images were initially masked, and monkeys were trained to gradually reveal the images by touching a "reveal button." Monkeys could choose to classify images at any time or to reveal more of the images. Thus, they had the opportunity to assess when enough of an image had been revealed to support accurate classification. In Experiment 1, monkeys made more reveal responses before classifying when smaller amounts of the image were revealed by each button touch. In Experiment 2, to-be-classified images were shrunk and covered by 1 critical blocker among other blockers that did not provide information when removed. Monkeys made more reveal responses as the critical blocker was removed later in the trial. In Experiment 3, monkeys were presented with previously classified images with either more or fewer blockers obscuring the image than was the case when they chose to classify that image previously. Monkeys made more reveal responses when information was insufficient than when it was excessive. These results indicate that monkeys dynamically monitor evolving decision processes and adaptively collect information as necessary to maintain accuracy.