Don't look back on failure: spontaneous uncertainty monitoring in chimpanzees.

During computer-controlled cognitive tasks, chimpanzees often look up at the food dispenser, which activates at the same time as feedback for the correct choice but not for feedback for the incorrect choice. Do these "looking back" behaviors also indicate signs of spontaneous monitoring of their confidence in their choices? To address this question, we delayed the feedback for 1 s after their choice responses and observed their look-back behaviors during the delay period. Two chimpanzees looked up at the food dispenser significantly less frequently when their choice was incorrect (but the feedback was not given) than when it was correct. These look-back behaviors have not been explicitly trained under experimental contexts. Therefore, these results indicate that chimpanzees spontaneously change the frequency of their look-back behaviors in response to the correctness or incorrectness of their own choices, even without external feedback, suggesting that their look-back behaviors may reflect the level of "confidence" or "uncertainty" of their responses immediately before.

Learning to recognize uncertainty vs. recognizing uncertainty to learn: Confidence judgments and exploration decisions in preschoolers.

During exploration, young children often show an intuitive sensitivity to uncertainty, despite their strong tendency towards overconfidence in their explicit judgments. Here, we examine the development of children's explicit and implicit recognition of uncertainty using the same stimuli. We presented 4- and 5-year-olds with objects that varied in their amount of perceptual occlusion, and assessed their ability to distinguish among them using two types of measures. Experiment 1 used a traditional 3-point confidence scale to examine children's explicit uncertainty judgments. We compared these confidence judgments before and after they observed disconfirming evidence, to assess the impact of this experience on their acknowledgement of uncertainty in later trials. Experiment 2 examined children's exploration preference as a measure of implicit sensitivity to uncertainty. Our results indicate that children intuitively recognize gaps in their knowledge, and that this implicit recognition may be leveraged to support their explicit judgments. Specifically, we found that children's baseline confidence judgments improved significantly following the presentation of disconfirming evidence. Furthermore, when asked to make exploration decisions about the same set of objects, children showed a spontaneous sensitivity to uncertainty, prior to any evidence. Taken together, these results suggest that children's exploration behavior may be used as an early developing measure of uncertainty control and raise the intriguing possibility that the experience of unexpected outcomes may play a role in the development of metacognition.

Relationships between implicit and explicit uncertainty monitoring and mindreading: Evidence from autism spectrum disorder.

We examined performance on implicit (non-verbal) and explicit (verbal) uncertainty-monitoring tasks among neurotypical participants and participants with autism, while also testing mindreading abilities in both groups. We found that: (i) performance of autistic participants was unimpaired on the implicit uncertainty-monitoring task, while being significantly impaired on the explicit task; (ii) performance on the explicit task was correlated with performance on mindreading tasks in both groups, whereas performance on the implicit uncertainty-monitoring task was not; and (iii) performance on implicit and explicit uncertainty-monitoring tasks was not correlated. The results support the view that (a) explicit uncertainty-monitoring draws on the same cognitive faculty as mindreading whereas (b) implicit uncertainty-monitoring only test first-order decision making. These findings support the theory that metacognition and mindreading are underpinned by the same meta-representational faculty/resources, and that the implicit uncertainty-monitoring tasks that are frequently used with non-human animals fail to demonstrate the presence of metacognitive abilities.

A metacognitive illusion in monkeys.

Like humans, monkeys can make accurate judgements about their own memory by reporting their confidence during cognitive tasks. Some have suggested that animals use associative learning to make accurate confidence judgements, while others have suggested animals directly access and estimate the strength of their memories. Here we test a third, non-exclusive possibility: perhaps monkeys, like humans, base metacognitive inferences on heuristic cues. Humans are known to use cues like perceptual fluency (e.g. how easy something is to see) when making metacognitive judgements. We tested monkeys using a match-to-sample task in which the perceptual fluency of the stimuli was manipulated. The monkeys made confidence wagers on their accuracy before or after each trial. We found that monkeys' wagers were affected by perceptual fluency even when their accuracy was not. This is novel evidence that animals are susceptible to metacognitive illusions similar to those experienced by humans.

Assessment of metacognitive monitoring and control in baboons (Papio papio).

Metacognition refers to the ability of an organism to evaluate its states of knowledge (metacognitive monitoring) and engage in appropriate information-seeking behaviors when a lack of knowledge is detected (metacognitive control). This study assessed metacognitive monitoring and control in three Guinea baboons (Papio papio). Monkeys were required to report on a touchscreen the location of two target stimuli that had previously appeared briefly on a grid. They could either respond directly or use a "Repeat" key providing an opportunity to repeat the target stimuli. In Experiment 1, the baboons used the Repeat key more frequently in difficult trials and transferred this use of the key to novel conditions. Two baboons showed higher accuracy when they declined using the key compared to Baseline trials in which the key was not available, suggesting accurate metacognitive monitoring judgments. The same two baboons were consistently faster at reporting the targets' locations after a repetition of the stimulus. In Experiment 2, the baboons had to choose between two Repeat keys, one for each target. Two baboons showed a preference for repeating the presentation of the less visible target, suggesting that they identified what information they lack. Overall, results support the hypothesis of metacognitive monitoring in baboons, and also provide limited evidence for metacognitive control. We propose that tests requiring subjects to choose between several metacognitive responses in computerized tasks provide a suitable new approach for studying targeted information-seeking behaviors in animals.

Children weigh the number of informants and perceptual uncertainty when identifying objects.

The aim of this study was to evaluate how 3- to 5-year-old children (N = 150) identify an object when they are confronted with conflicting evidence, notably when the available perceptual evidence is contradicted by the testimony of either a lone informant or a three-informant consensus. Results showed that (a) 5-year-olds were more likely than 3- or 4-year-olds to rely on the perceptual evidence, ignoring claims made by the informants; (b) the three-informant consensus had more impact than a single informant for all age groups; and (c) children were more likely to make a perception-based response if the stimulus was perceptually unambiguous rather than equivocal with respect to its identity. Moreover, when children's task was to identify equivocal stimuli, they endorsed the three-informant consensus more than the lone informant. In contrast, when they needed to identify unambiguous stimuli, the number of informants did not influence children's responses. Taken together, the results show that the tendency to resist testimony on the basis of perceptual evidence increases with age. Moreover, preschoolers monitor both the characteristics of their informants and the relative ambiguity of the perceptual stimuli when they need to weigh verbal testimony against perceptual evidence.

The interplay between uncertainty monitoring and working memory: Can metacognition become automatic?

The uncertainty response has grounded the study of metacognition in nonhuman animals. Recent research has explored the processes supporting uncertainty monitoring in monkeys. It has revealed that uncertainty responding, in contrast to perceptual responding, depends on significant working memory resources. The aim of the present study was to expand this research by examining whether uncertainty monitoring is also working memory demanding in humans. To explore this issue, human participants were tested with or without a cognitive load on a psychophysical discrimination task that included either an uncertainty response (allowing the participant to decline difficult trials) or a middle-perceptual response (labeling the same intermediate trial levels). The results demonstrated that cognitive load reduced uncertainty responding, but increased middle responding. However, this dissociation between uncertainty and middle responding was only observed when participants either lacked training or had very little training with the uncertainty response. If more training was provided, the effect of load was small. These results suggest that uncertainty responding is resource demanding, but with sufficient training, human participants can respond to uncertainty either by using minimal working memory resources or by effectively sharing resources. These results are discussed in relation to the literature on animal and human metacognition.

Capuchin monkeys (sometimes) go when they know: Confidence movements in Sapajus apella.

To test for evidence of metacognition in capuchin monkeys (Sapajus apella), we analyzed confidence movements using a paradigm adapted from research with chimpanzees. Capuchin monkeys provide an interesting model species for the comparative assessment of metacognition as they show limited evidence of such cognitive-monitoring processes in a variety of metacognition paradigms. Here, monkeys were presented with a computerized delayed matching-to-sample (DMTS) memory test in one location but were rewarded for correct responses in a separate location. Movements could be made from one location to the other at any time, but movements between a response and reward feedback may reflect confidence in the accuracy of the response. Critically, DMTS tests included occasional "no sample" trials where monkeys' performance was at chance when the trial started without a sample and a 1-s interval to the response options. We predicted that monkeys would (1) perform less accurately (and less confidently) at longer retention intervals, (2) move to the dispenser early more often on trials completed correctly than incorrectly, and (3) show a relation between faster response latency and early movements. Analyses of response times and "go" or "no go" confidence movements before feedback to the reward location suggested that the monkeys were capable of monitoring confidence in their responses. However, their confidence movements were less precise and less flexible than chimpanzees. Overall, this paradigm can reveal potential metacognitive abilities in nonhuman animals that otherwise demonstrate these abilities inconsistently.

Divide and Conquer.

We assessed the ability of preschool children to assign the most difficult tasks to a symbolic helper. First, children were taught that a toy "helper" could aid them in remembering the location of a hidden item. Children preferentially assigned the helper to the objectively most difficult locations to remember. Each child then completed eight more tests, assessing a range of different skills such as counting, object identification, and word reading. Children again could assign some stimuli in each task to the helper, leaving the remaining stimuli for themselves to respond to in the given tasks. They were not explicitly told to assign the hardest stimulus to the helper. However, children consistently still did so in most tasks, although some tasks showed an effect of age where older children were more proficient in assigning the objectively more difficult stimuli to the helper. These results highlight a potential form of metacognition in young children in which they can monitor difficulty across varied kinds of assessments and use a generalized tool for asking for help that does not require verbal responding.

Exploring Potential Mechanisms Underlying the Lack of Uncertainty Monitoring in Capuchin Monkeys.

In a widely used animal-metacognition paradigm, monkeys are positively reinforced with food for correct classifications of stimuli as sparse or dense and punished with timeouts for incorrect responses, but they also have access to an "uncertainty" response that moves them to the next trial without either of these forms of feedback. Rhesus monkeys use this uncertainty response most often for trials on which they are at greatest risk for making an error, suggesting that they are monitoring their ability to make these classifications. Capuchin monkeys do not succeed to the same degree on these tasks-conceivably as a result of differential contingencies in place in all existing studies between the sparse/dense responses (food delivery or timeout) and the uncertainty response (avoidance of a timeout but also no chance for food reward). Here, we used a novel variation of this task in which the outcomes of the three response classes (sparse, dense, uncertain) were functionally equivalent. All responses simply determined the delay interval before presentation of a second task (matching-to-sample), and that task yielded potential food rewards. Overall, capuchin monkeys used the dense and sparse responses appropriately, including some animals that had no prior experience in performing this classification task. However, none used the uncertainty response appropriately even when it was placed on the same contingency plane as the dense and sparse responses. This suggests that the failure of capuchin monkeys to use an uncertainty response is not the result of that response producing a qualitatively different outcome compared to the dense and sparse responses.

Inaugurating the Study of Animal Metacognition.

Metacognition-the ability to monitor and control one's own cognition-is a sophisticated ability that reveals humans' reflective mind and consciousness. Researchers have begun to explore whether animals share humans' metacognitive capacity. This article reprises the original study that explored metacognition across species. A captive dolphin performed an auditory pitch-discrimination task using High/Low discrimination responses and an Uncertainty response with which he could decline to complete any trials he chose. He selectively declined the difficult trials near his discriminative threshold-just as humans do. This comparative exploration of metacognition required a trial-intensive titration of perceptual threshold and the training of a distinctive behavioral response. It could not have been conducted in the wild, though the naturalistic observation of dolphin uncertainty behaviors and risk-management strategies would no doubt yield complementary insights. The dolphin study inaugurated a new area of cross-species research. This research area opens a new window on reflective mind in animals, illuminates the phylogenetic emergence of metacognition, and may reveal the antecedents of human consciousness.

Metacognition in animals: Trends and challenges.

There is widespread agreement that metacognition is not demonstrated if alternative explanations account for putative meta-cognition data. However, there is less agreement on which studies are protected from alternative explanations. We have argued that existing experiments on uncertainty monitoring can be explained by low-level explanations without assuming metacognition (Crystal & Foote, 2009). The field would benefit from the development of accepted standards for what is required to produce a convincing example of metacognition in animals.

Metacognition in animals.

Metacognition is thinking about thinking. There is considerable interest in developing animal models of metacognition to provide insight about the evolution of mind and a basis for investigating neurobiological mechanisms of cognitive impairments in people. Formal modeling of low-level (i.e., alternative) mechanisms has recently demonstrated that prevailing standards for documenting metacognition are inadequate. Indeed, low-level mechanisms are sufficient to explain data from existing methods. Consequently, an assessment of what is 'lost' (in terms of existing methods and data) necessitates the development of new, innovative methods for metacognition. Development of new methods may prompt the establishment of new standards for documenting metacognition.