Prospective and concurrent metamemory of familiarity and working memory by rhesus monkeys

Monkeys sometimes accurately predict their memory accuracy, a form of metamemory. The memory signals that support this ability may differ between memory systems and depend on when memory judgments are made. Working memory requires active maintenance through the delay interval. Familiarity allows recognition without active maintenance and is triggered by representation of memoranda at test. We measured metamemory prospectively, during delay intervals, and concurrently, at the time of tests, while six male rhesus monkeys performed tasks that favored working memory or familiarity. Metamemory was accurate at both times in both tasks, and highest for concurrent judgments in the familiarity task.