Change in the relative contributions of habit and working memory facilitates serial reversal learning expertise in rhesus monkeys

Abstract

Functionally distinct memory systems likely evolved in response to incompatible demands placed on learning by distinct environmental conditions. Working memory appears adapted, in part, for conditions that change frequently, making rapid acquisition and brief retention of information appropriate. In contrast, habits form gradually over many experiences, adapting organisms to contingencies of reinforcement that are stable over relatively long intervals. Serial reversal learning provides an opportunity to simultaneously examine the processes involved in adapting to rapidly changing and relatively stable contingencies. In serial reversal learning, selecting one of the two simultaneously presented stimuli is positively reinforced, while selection of the other is not. After a preference for the positive stimulus develops, the contingencies of reinforcement reverse. Naïve subjects adapt to such reversals gradually, perseverating in selection of the previously rewarded stimulus. Experts reverse rapidly according to a win-stay, lose-shift response pattern. We assessed whether a change in the relative control of choice by habit and working memory accounts for the development of serial reversal learning expertise. Across three experiments, we applied manipulations intended to attenuate the contribution of working memory but leave the contribution of habit intact. We contrasted performance following long and short intervals in Experiments 1 and 2, and we interposed a competing cognitive load between trials in Experiment 3. These manipulations slowed the acquisition of reversals in expert subjects, but not naïve subjects, indicating that serial reversal learning expertise is facilitated by a shift in the control of choice from passively acquired habit to actively maintained working memory.

Cognitive flexibility in the wild: Individual differences in reversal learning are explained primarily by proactive interference, not by sampling strategies, in two passerine bird species

“…Here, we have identified proactive interference as a repeatable trait that underlies most of the among-individual variation in reversal-learning performance, at least for one of two species, and probably the other. This suggests that other processes that may contribute to variation in reversallearning performance, such as the formation of an excitatory association with the currently rewarded feeder and of inhibitory associations with the non-rewarded feeders, or the utilization of working memory (Hassett & Hampton, 2017), do not do so at the among-individual level, although they could be repeatable traits in other test contexts (e.g., discrimination tests; Cauchoix et al, 2018). A natural extension of this work would examine whether proactive interference errors can themselves be decomposed into further constituents with significant among-individual variation (e.g., perseveration vs. learned non-reward; Nilsson et al, 2015), as well as their covariation with other phenotypic and life-history traits.…”

The face of animal cognition

“…Although there has been a flurry of attention directed especially at the functional aspects of cognition, work on its mechanistic basis (to which most effort in cognition is addressed) has calmly proceeded, again with an increasing diversity of species, contexts and experimental paradigms. Some of the work keeps much to traditional lines, such as mechanisms underlying decision-making in rats (Zentall et al 2017), processing of words and nonwords in pigeons (Scarf et al 2016), and serial reversal learning in monkeys (Hassett & Hampton 2017).…”

Behavioral Research on Captive Animals: Scientific and Ethical Concerns

“…Much of the behavioral research at Yerkes takes place in "sound attenuating booths" with computer touch screens, as well as a "foraging room" where monkeys "explore and learn in a large area where food can be hidden and puzzles presented" (Laboratory of Comparative Primate Cognition, n.d.). Recent behavioral research at Yerkes involves monkeys (e.g., Brown, Templer, and Hampton, 2017;Hassett and Hampton 2017), orangutans (e.g., Diamond et al, 2016), and chimpanzees (e.g., Krachun et al, 2016). What is more, the Comparative Intelligence and Cognition Laboratory at the Language Research Center at Georgia State University conducts a wide range of comparative experiments on chimpanzees, capuchin monkeys, rhesus monkeys, and human infants and adults.…”