Metacognitive monkeys or associative animals? Simple reinforcement learning explains uncertainty in nonhuman animals

Monkeys will selectively and adaptively learn to avoid the most difficult trials of a perceptual discrimination learning task. Couchman, Coutinho, Beran, and Smith (2010) have recently demonstrated that this pattern of responding does not depend on animals receiving trial-by-trial feedback for their responses; it also obtains if experience of the most difficult trials occurs only under conditions of deferred feedback. Couchman et al. argued that this ruled out accounts based on low-level processes of associative learning and instead required explanation in terms of metacognitive processes of decision monitoring. Contrary to this argument, a simple associative model of reinforcement learning is shown to account for the key findings of Couchman et al.'s empirical study, along with several other findings that have previously been claimed to challenge associative models.