Capuchin monkeys (Cebus apella) modulate their use of an uncertainty response depending on risk.

Abstract

Metacognition refers to thinking about thinking, and there has been a great deal of interest in how this ability manifests across primates. Based on much of the work to date, a tentative division has been drawn with New World monkeys on one side and Old World monkeys and apes on the other. Specifically, Old World monkeys, apes and humans often show patterns reflecting metacognition, but New World monkeys typically fail to do so, or show less convincing behavioral patterns. However, recent data suggests that this difference may relate to other aspects of some experimental tasks. For example, one possibility is that risk tolerance affects how capuchin monkeys, a New World primate species, tend to perform. Specifically, it has recently been argued that on tasks in which there are two or three options, the ‘risk’ of guessing is tolerable for capuchins since there is a high probability of being correct even if they ‘know they do not know’ or feel something akin to uncertainty. The current study investigated this possibility by manipulating the degree of risk (2-choices versus 6-choices) and found that capuchin monkeys used the uncertainty response more on 6-choice trials than on 2-choice trials. We also found that rate of reward does not appear to underlie these patterns of performance, and propose that the degree of risk is modulating the use of the uncertainty response in capuchin monkeys. Thus, the apparent differences between New and Old world monkeys in metacognition may reflect differences in risk tolerance rather than access to metacognitive states.

Not knowing what one knows: A Meaningful failure of metacognition in capuchin monkeys.

“…However, capuchin monkeys did appropriately use the UR more frequently than they had in Beran et al (2009). Beran, Perdue, Church, and Smith (2016) tested the hypothesis that the capuchin monkeys' failure at using the UR in Beran et al (2009) was due to their greater tolerance-compared to macaques-for receiving the punitive timeout for making an incorrect response. Whereas the contingencies granted a 0.50 probability of obtaining a pellet with random selections in Beran et al (2009 the contingency only granted a .166 probability of receiving a pellet for guessing.…”

“…Every human would "phone a friend" to seek information if their life were on the line. So perhaps the data from Beran et al (2014Beran et al ( , 2016 show that the degree of risk is a crucial factor for inducing control processes within a metacognitive but risk-tolerant system. The "glimmerings" of metacognitive-like patterns shown by capuchin monkeys by different teams with different tasks that were outlined earlier all appear also to support this possibility, given that in nearly all of those tasks, the costs for failure were not high relative to normal research methods in comparative cognition research.…”

“…Existing data may reflect this possibility. Beran et al (2014Beran et al ( , 2016 showed that capuchin monkeys may be more risk tolerant than other species given discrimination tasks with a 50% chance level, and therefore may not engage control mechanisms even in the presence of some form of monitoring process unless the likelihood of failure is too high. Capuchin monkeys are known to be highly manipulative and engage in a variety of foraging behaviors, suggesting perhaps that ecological pressures have selected for a certain degree of risk tolerance in that species.…”

“…Perhaps this explained why capuchin monkeys now used the UR more effectively. Accordingly, Beran et al (2016) had capuchin monkeys engage a shape-size discrimination task with an escape response (similar to Beran et al, 2014), but in blocks of 1,500 trials the number of foils alternated between one foil (0.50 probability of a successful guess) and five foils (0.166 probability of a successful guess). The capuchin monkey did not use the UR in the 1-foil trials, but did use it more with the 5-foil trials.…”

Rats know when they remember: transfer of metacognitive responding across odor-based delayed match-to-sample tests

“…Demonstrations of some aspects of metacognitive behavior in pigeons (Adams & Santi, 2011; Zentall and Stagner, 2010) and capuchin monkeys (Beran, Perdue, Church, & Smith, 2016) have been more convincing, but certainly not as substantial as those in macaque monkeys (Beran et al, 2016). In the few studies that exist, evidence for metacognition in rats is also mixed (Foote & Crystal, 2017; 2012; Kirk et al, 2014; Yuki & Okanoya, 2017).…”