Behavioral and Neural Indices of Metacognitive Sensitivity in Preverbal Infants

Abstract

SummaryHumans adapt their behavior not only by observing the consequences of their actions but also by internally monitoring their performance. This capacity, termed metacognitive sensitivity [1, 2], has traditionally been denied to young children because they have poor capacities in verbally reporting their own mental states [3, 4, 5]. Yet, these observations might reflect children’s limited capacities for explicit self-reports, rather than limitations in metacognition per se. Indeed, metacognitive sensitivity has been shown to reflect simple computational mechanisms [1, 6, 7, 8], and can be found in various non-verbal species [7, 8, 9, 10]. Thus, it might be that this faculty is present early in development, although it would be discernible through implicit behaviors and neural indices rather than explicit self-reports. Here, by relying on such non-verbal indices, we show that 12- and 18-month-old infants internally monitor the accuracy of their own decisions. At the behavioral level, infants showed increased persistence in their initial choice after making a correct as compared to an incorrect response, evidencing an appropriate evaluation of decision confidence. Moreover, infants were able to use decision confidence adaptively to either confirm their initial choice or change their mind. At the neural level, we found that a well-established electrophysiological signature of error monitoring in adults, the error-related negativity, is similarly elicited when infants make an incorrect choice. Hence, although explicit forms of metacognition mature later during childhood, infants already estimate decision confidence, monitor their errors, and use these metacognitive evaluations to regulate subsequent behavior.

Metacognition: Pre-verbal Infants Adapt Their Behaviour to Their Knowledge States

“…But let's say that Goupil and Kouider's [4] demonstration really does provide convincing evidence for early metarepresentational abilities. After all, perhaps this is the most plausible interpretation given that infants of the same age are seemingly able to metarepresent the knowledge states of others [9].…”

“…Goupil and Kouider [4] have thus provided much needed new data on this difficult topic. Developmental psychologists' avoidance of this topic is not at all surprising given the on-going debate about what constitutes satisfying non-verbal evidence for metacognition.…”

“…Finally, a more direct measure of acknowledging a wrong decision was captured using electroencephalography (EEG): a particular EEG component, the error related negativity (ERN), is observed in adults when they make an incorrect decision. Goupil and Kouider [4] measured an ERN-like response when infants oriented towards the incorrect side of the screen after the other side had been primed by the appearance of a face, when that face had been on the screen for long enough to be visible.…”

“…For their first study, Goupil and Kouider [4] adapted this paradigm for use with 18-month old infants ( Figure 1). Response uncertainty was induced by asking children to indicate the location where they had seen a toy hidden after a variable delay.…”

“…More importantly, many non-human species, including rats [3], have been shown to adapt their behaviour when faced with uncertainty, in ways that suggest they are able to access their knowledge states. It is therefore more reassuring than surprising that human infants are capable of no less: in this issue of Current Biology, Goupil and Kouider [4] report how they adapted paradigms previously used in animal studies to show that 12-month old and 18-month-old human infants persist in their choices only when they are likely to have been correct (suggesting that they know that they know) and change their mind when they are likely to have been be wrong (an index of error detection). …”