Belief-based action prediction in preverbal infants

Meaning as mentalization

The way we establish meaning has been a profound question not only in language research but in developmental science as well. The relation between linguistic form and content has been loosened up in recent pragmatic approaches to communication, showing that code-based models of language comprehension must be augmented by context-sensitive, pragmatic-inferential mechanisms to recover the speaker's intended meaning. Language acquisition has traditionally been thought to involve building a mental lexicon and extracting syntactic rules from noisy linguistic input, while communicative-pragmatic inferences have also been argued to be indispensable. Recent research findings exploring the electrophysiological indicator of semantic processing, the N400, have raised serious questions about the traditional separation between semantic decoding and pragmatic inferential processes. The N400 appears to be sensitive to mentalization-the ability to attribute beliefs to social partners-already from its developmental onset. This finding raises the possibility that mentalization may not simply contribute to pragmatic inferences that enrich linguistic decoding processes but that the semantic system may be functioning in a fundamentally mentalistic manner. The present review first summarizes the key contributions of pragmatic models of communication to language comprehension. Then, it provides an overview of how communicative intentions are interpreted in developmental theories of communication, with a special emphasis on mentalization. Next, it discusses the sensitivity of infants to the information-transmitting potential of language, their ability to pick up its code-like features, and their capacity to track language comprehension of social partners using mentalization. In conclusion, I argue that the recovery of meaning during linguistic communication is not adequately modeled as a process of code-based semantic retrieval complemented by pragmatic inferences. Instead, the semantic system may establish meaning, as intended, during language comprehension and acquisition through mentalistic attribution of content to communicative partners.

Is self-awareness necessary to have a theory of mind?

Forty years ago, Gallup proposed that theory of mind presupposes self-awareness. Following Humphrey, his hypothesis was that individuals can infer the mental states of others thanks to the ability to monitor their own mental states in similar circumstances. Since then, advances in several disciplines, such as comparative and developmental psychology, have provided empirical evidence to test Gallup's hypothesis. Herein, we review and discuss this evidence.

Selective Action Prediction in Infancy Depending on Linguistic Cues: An EEG and Eyetracker Study

Humans' capacity to predict actions and to socially categorize individuals is at the basis of social cognition. Such capacities emerge in early infancy. By 6 months of age, infants predict others' reaching actions considering others' epistemic state. At a similar age, infants are biased to attend to and interact with more familiar individuals, considering adult-like social categories such as the language people speak. We report that these two core processes are interrelated early on in infancy. In a belief-based action prediction task, 6-month-old infants (males and females) presented with a native speaker generated online predictions about the agent's actions, as revealed by the activation of participants' sensorimotor areas before the agent's movement. However, infants who were presented with a foreign speaker did not recruit their motor system before the agent's action. The eyetracker analysis provided further evidence that linguistic group familiarity influences how infants predict others' actions, as only infants presented with a native speaker modified their attention to the stimuli as a function of the agent's forthcoming behavior. The current findings suggest that infants' emerging capacity to predict others' actions is modulated by social cues, such as others' linguistic group. A facilitation to predict and encode the actions of native speakers relative to foreign speakers may explain, in part, why infants preferentially attend to, imitate, and learn from the actions of native speakers.

Talking About the Absent and the Abstract: Referential Communication in Language and Gesture

Human language permits us to call to mind objects, events, and ideas that we cannot witness directly, either because they are absent or because they have no physical form (e.g., people we have not met, concepts like justice). What enables language to transmit such knowledge? We propose that a referential link between words, referents, and mental representations of those referents is key. This link enables us to form, access, and modify mental representations even when the referents themselves are absent ("absent reference"). In this review we consider the developmental and evolutionary origins of absent reference, integrating previously disparate literatures on absent reference in language and gesture in very young humans and gesture in nonhuman primates. We first evaluate when and how infants acquire absent reference during the process of language acquisition. With this as a foundation, we consider the evidence for absent reference in gesture in infants and in nonhuman primates. Finally, having woven these literatures together, we highlight new lines of research that promise to sharpen our understanding of the development of reference and its role in learning about the absent and the abstract.

Objects in a social world: Infants' object representational capacity limits are shaped by objects' social relevance

Several decades of research have revealed consistent signature limits on infants' ability to represent objects. However, these signature representational limits were established with methods that often removed objects from their most common context. In infants' everyday lives, objects are very often social artifacts: they are the targets of agents' goal-directed actions, communications, and beliefs, and may have social content or relevance themselves. In this chapter, we explore the relationship between infants' object representational capacity limits and their processing of the social world. We review evidence that the social content and context of objects can shift infants' object representational limits. We discuss how taking the social world into account can yield more robust and ecologically valid estimates of infants' early representational capacities.

Extending the use of the Belief Action Outcome model during COVID-19 pandemic: Technology access review on locational disparities and inequalities for knowledge workers

Remote working has played an increasingly important role in accelerating alternative workplaces. In the wake of the COVID-19 pandemic emergency demands, this paper seek to demonstrate the resilience of knowledge workers and their ability to work remotely, despite the uneven distribution of enabling infrastructure during the COVID-19 lockdown restrictions. The Belief Action Outcome (BAO) model for information systems was used to support the study as this underexplored theory was found to be worthy of further testing in real-world situations. This qualitative study used a range of sources consisting largely of search data from major online journal databases. The findings highlight that knowledge workers can successfully work from alternative workplaces and still deliver the required outputs, despite socio-economic problems such as locational disparities and inequalities in access to technology. The same technologies that empowered knowledge workers to transform their work locations during the COVID-19 crisis, however, are the same to enable certain sectors of society whilst hindering other cohorts residing in under resourced locations. Therefore, the benefits of working remotely cannot favour everyone because of the existing inequalities and disparities. Applying the BAO model in this context implies environmental issues are likely to play a growing important role in future when decisions are made around alternative workplace and adoption of IS/IT systems. Although the COVID-19 pandemic has disrupted working patterns and accelerated the trend towards working in alternative workplaces than the traditional office/factory premises, there are notable implications around this shift. The study confirmed the related behaviours, opportunities, and barriers (social systems and organisations), as well as the structures (both societal and organisational) of the BAO model. In addition, certain aspects of both the remote workers’ and organisations’ adoption behaviour were changed to a greater extent and more rapidly because of the COVID-19 pandemic. As a contribution, this qualitative study reveals in more detail the yet uncharted remote workers' beliefs.

Development of cool and hot theory of mind and cool and hot inhibitory control abilities from 3.5 to 6.5 years of age

Attributing affectively neutral mental states such as thoughts (i.e., cool theory of mind, cool ToM) to others appears to be rooted in different processes than the ones involved in attributing affectively charged mental states such as emotions (i.e., hot ToM) to others. However, no study has investigated the developmental pattern of hot and cool ToM abilities using a similar task and the relative contribution of cool and hot inhibitory control (IC) to cool and hot ToM development. To do so, we tested 112 children aged 3.5 to 6.5 years on a cool and a hot version of a ToM task and on a cool and hot version of an IC task. We found that hot ToM abilities developed more rapidly than cool ToM. Importantly, we found that hot IC abilities mediated the relation between age and hot ToM abilities. Taken together, our results suggest that the ability to attribute emotions to others develops more rapidly than the ability to attribute thoughts and that the growing efficiency of hot ToM with age is specifically rooted in the growing efficiency of hot IC abilities.

Seeing the World From Others' Perspective: 14-Month-Olds Show Altercentric Modulation Effects by Others' Beliefs

Humans have a propensity to readily adopt others' perspective, which often influences their behavior even when it seemingly should not. This altercentric influence has been widely studied in adults, yet we lack an understanding of its ontogenetic origins. The current studies investigated whether 14-month-olds' search in a box for potential objects is modulated by another person's belief about the box's content. We varied the person's potential belief such that in her presence/absence an object was removed, added, or exchanged for another, leading to her true/false belief about the object's presence (Experiment 1, n = 96); or transformed into another object, leading to her true/false belief about the object's identity (i.e., the objects represented under a specific aspect, Experiment 2, n = 32). Infants searched longer if the other person believed that an object remained in the box, showing an altercentric influence early in development. These results suggest that infants spontaneously represent others' beliefs involving multiple objects and raise the possibility that infants can appreciate that others encode the world under a unique aspect.

Sensorimotor Activity and Network Connectivity to Dynamic and Static Emotional Faces in 7-Month-Old Infants

The present study investigated whether, as in adults, 7-month-old infants’ sensorimotor brain areas are recruited in response to the observation of emotional facial expressions. Activity of the sensorimotor cortex, as indexed by µ rhythm suppression, was recorded using electroencephalography (EEG) while infants observed neutral, angry, and happy facial expressions either in a static (N = 19) or dynamic (N = 19) condition. Graph theory analysis was used to investigate to which extent neural activity was functionally localized in specific cortical areas. Happy facial expressions elicited greater sensorimotor activation compared to angry faces in the dynamic experimental condition, while no difference was found between the three expressions in the static condition. Results also revealed that happy but not angry nor neutral expressions elicited a significant right-lateralized activation in the dynamic condition. Furthermore, dynamic emotional faces generated more efficient processing as they elicited higher global efficiency and lower networks’ diameter compared to static faces. Overall, current results suggest that, contrarily to neutral and angry faces, happy expressions elicit sensorimotor activity at 7 months and dynamic emotional faces are more efficiently processed by functional brain networks. Finally, current data provide evidence of the existence of a right-lateralized activity for the processing of happy facial expressions.

The Developmental Differences of Implicit Theory of Mind in Infants Using Anticipatory Looking Paradigm

Objectives: This study examined the developmental differences of implicit theory of mind in infants aged 12 to 24 months according to two types of tasks within the anticipatory looking paradigm, as well as the interaction between age group and type of task.Methods: In all, 69 infants participated in this study aged 12, 18, and 24 months. Two types of implicit false-belief tasks using an anticipatory looking paradigm were administered to all the infants for about 4 minutes 20 seconds. While all of the infants watched two types of computerized video clips (FB1, FB2) through the computer screen, an eye-tracker (TobiiX120) recorded the traces of anticipatory looking of infants. The anticipatory looking of infants in test trials was then analyzed.Results: Results showed that the differences between the 12-month-olds and the other age groups (18-month-olds, 24-month-olds) were significant, but even some of the 12-month-olds showed evidence of an implicit theory of mind. The level of implicit theory of mind of 18-month infants did not significantly differ from that of 24-month infants. In addition, a difference by type of implicit false-belief task was significant. Infants showed a higher level of implicit theory of mind in Task1 (FB1) than in Task2 (FB2). However, the interaction effect between age and type of task was not significant.Conclusion: The findings of this study hold implications for the development of implicit theory of mind early in life, and indicate the validity of the anticipatory looking paradigm with two types of tasks. Several limitations and suggestions for future study are also presented.

Acquiring verbal reference: The interplay of cognitive, linguistic, and general learning capacities

Verbal reference is the ability to use language to communicate about objects, events, or ideas, even if they are not witnessed directly, such as past events or faraway places. It rests on a three-way link between words, their referents, and mental representations of those referents. A foundational human capacity, verbal reference extends the communicative power of language beyond the here-and-now, enabling access to language-mediated learning and thus fueling cognitive development. In the current review, we consider how and when verbal reference develops. The existing literature suggests that verbal reference emerges around infants' first birthdays and becomes increasingly robust by their second. In discussing the powerful developmental advantages of acquiring verbal reference we propose that this achievement requires a dynamic interplay among infants' cognitive and language development, fueled by general learning capacities. We close by describing new research directions, aimed at advancing our understanding of how verbal reference emerges.

Stopping at nothing: Two-year-olds differentiate between interrupted and abandoned goals

Previous research has established that goal tracking emerges early in the first year of life and rapidly becomes increasingly sophisticated. However, it has not yet been shown whether young children continue to update their representations of others' goals over time. The current study investigated this by probing young children's (24- to 30-month-olds; N = 24) ability to differentiate between goal-directed actions that have been halted because the goal was interrupted and those that have been halted because the goal was abandoned. To test whether children are sensitive to this distinction, we manipulated the experimenter's reason for not completing a goal-directed action; his initial goal was either interrupted by an obstacle or abandoned in favor of an alternative. We measured whether children's helping behavior was sensitive to the experimenter's reason for not completing his goal-directed action by recording whether children completed the experimenter's initial goal or the alternative goal. The results showed that children helped to complete the experimenter's initial goal significantly more often after this goal had been interrupted than after it had been abandoned. These results support the hypothesis that children continue to update their representations of others' goals over time by 2 years of age and specifically that they differentiate between abandoned and interrupted goals.

Five-month-old infants attribute inferences based on general knowledge to agents

To make sense of others' actions, we generally consider what information is available to them. This information may come from different sources, including perception and inference. Like adults, young infants track what information agents can obtain through perception: If an agent directly observes an event, for example, young infants expect the agent to have information about it. However, no investigation has yet examined whether young infants also track what information agents can obtain through inference, by bringing to bear relevant general knowledge. Building on the finding that by 4 months of age most infants have acquired the physical rule that wide objects can fit into wide containers but not narrow containers, we asked whether 5-month-olds would expect an agent who was searching for a wide toy hidden in her absence to reach for a wide box as opposed to a narrow box. Infants looked significantly longer when the agent selected the narrow box, suggesting that they expected her (a) to share the physical knowledge that wide objects can fit only into wide containers and (b) to infer that the wide toy must be hidden in the wide box. Three additional conditions supported this interpretation. Together, these results cast doubt on two-system accounts of early psychological reasoning, which claim that infants' early-developing system is too inflexible and encapsulated to integrate inputs from other cognitive processes, such as physical reasoning. Instead, the results support one-system accounts and provide new evidence that young infants' burgeoning psychological-reasoning system is qualitatively similar to that of older children and adults.

Can infants adopt underspecified contents into attributed beliefs? Representational prerequisites of theory of mind

Recent evidence suggests that young infants, as well as nonhuman apes, can anticipate others' behavior based on their false beliefs. While such behaviors have been proposed to be accounted by simple associations between agents, objects, and locations, human adults are undoubtedly endowed with sophisticated theory of mind abilities. For example, they can attribute mental contents about abstract or non-existing entities, or beliefs whose content is poorly specified. While such endeavors may be human specific, it is unclear whether the representational apparatus that allows for encoding such beliefs is present early in development. In four experiments we asked whether 15-month-old infants are able to attribute beliefs with underspecified content, update their content later, and maintain attributed beliefs that are unknown to be true or false. In Experiment 1, infants observed as an agent hid an object to an unspecified location. This location was later revealed in the absence or presence of the agent, and the object was then hidden again to an unspecified location. Then the infants could search for the object while the agent was away. Their search was biased to the revealed location (that could be represented as the potential content of the agent's belief when she had not witnessed the re-hiding), suggesting that they (1) first attributed an underspecified belief to the agent, (2) later updated the content of this belief, and (3) were primed by this content in their own action even though its validity was unknown. This priming effect was absent when the agent witnessed the re-hiding of the object, and thus her belief about the earlier location of the object did not have to be sustained. The same effect was observed when infants searched for a different toy (Experiment 2) or when an additional spatial transformation was introduced (Experiment 4), but not when the spatial transformation disrupted belief updating (Experiment 3). These data suggest that infants' representational apparatus is prepared to efficiently track other agents' beliefs online, encode underspecified beliefs and define their content later, possibly reflecting a crucial characteristic of mature theory of mind: using a metarepresentational format for ascribed beliefs.

Inferring hidden objects from still and communicative onlookers at 8, 14, and 36 months of age

The current study investigated across five eye-tracking experiments children's developing skill of adopting others' referential perspective (Level 1 perspective taking) and to what extent it involves automatic processes or requires ostensive communicative cues. Three age groups (8-, 14-, and 36-month-olds) were tested on their expectation of an object appearing behind one of two peripheral occluders. A centrally presented person in profile either provided an ostensive communicative pointing cue or sat still, oriented to one of the two occluders. The 14-month-olds anticipated the hidden object when the onlooker had communicatively pointed to the location, as revealed by faster target detection in congruent trials (latency effect) and longer dwell times to the empty side in incongruent trials (violation-of-expectation effect). This was not the case when a still person was only oriented to one side. Adding emotional expressions to the still person (Experiment 2) did not help to produce the effects. However, at 36 months of age (Experiment 3), children showed both effects for the still person. The 8-month-olds did not show the violation-of-expectation effect for communicative pointing (Experiment 4) or for a matched abbreviated reach (Experiment 5b), showing it only for a complete reach behind the occluder (Experiment 5a), although they were faster to detect the congruent object in Experiment 4 and 5a. Findings reveal that automatic perspective taking develops after communicative perspective taking and that communicative perspective taking is a developmental outcome of the first year of life. The developmental pattern suggests a continuous social construction process of perspective-taking skills.

Altercentric Cognition: How Others Influence Our Cognitive Processing

Humans are ultrasocial, yet, theories of cognition have often been occupied with the solitary mind. Over the past decade, an increasing volume of work has revealed how individual cognition is influenced by the presence of others. Not only do we rapidly identify others in our environment, but we also align our attention with their attention, which influences what we perceive, represent, and remember, even when our immediate goals do not involve coordination. Here, we refer to the human sensitivity to others and to the targets and content of their attention as 'altercentrism'; and aim to bring seemingly disparate findings together, suggesting that they are all reflections of the altercentric nature of human cognition.

Electrophysiological investigation of infants' understanding of understanding

Social cognition might play a critical role in language acquisition and comprehension, as mindreading may be necessary to infer the intended meaning of linguistic expressions uttered by communicative partners. In three electrophysiological experiments, we explored the interplay between belief attribution and language comprehension of 14-month-old infants. First, we replicated our earlier finding: infants produced an N400 effect to correctly labelled objects when the labels did not match a communicative partner's beliefs about the referents. Second, we observed no N400 when we replaced the object with another category member. Third, when we named the objects incorrectly for infants, but congruently with the partner's false belief, we observed large N400 responses, suggesting that infants retained their own perspective in addition to that of the partner. We thus interpret the observed social N400 effect as a communicational expectancy indicator because it was contingent not on the attribution of false beliefs but on semantic expectations by both the self and the communicative partner. Additional exploratory analyses revealed an early, frontal, positive-going electrophysiological response in all three experiments, which was contingent on infants' computing the comprehension of the social partner based on attributed beliefs.

On the domain specificity of the mechanisms underpinning spontaneous anticipatory looks in false-belief tasks

Many studies proposed that infants' and adults' looking behavior suggest a spontaneous and implicit ability to reason about others' beliefs. It has been argued, however, that these successes are false positives due to domain-general processes, such as retroactive interference. In this study, we investigated the domain specificity of mechanisms underpinning participants' looking behavior by manipulating the dynamic cues in the event stimuli. Infants aged 15 and 20 months and adults saw animation events in which either a self-moving triangle, or a hand holding an identical inert triangle, chased an animated disk. Most 20-month-olds and adults showed belief congruent anticipatory looks in the agent-triangle condition, whereas they showed no bias in the inert triangle control condition. These results are not consistent with submentalizing accounts based on domain-general low-level processes and provide further support for domain-specific explanations positing an early-emerging mentalistic reasoning.

Mistaken max befriends Duplo girl: No difference between a standard and an acted-out false belief task

With their Duplo task, Rubio-Fernández and Geurts (2013) challenged the assumption that children under 4 years of age cannot pass the standard false belief test. In an attempt to replicate this task on a sample of 73 children aged 32–51 months, we added a standard change of location false belief task as well as a Duplo true belief task. Performance on the latter is crucial for interpreting answers in the Duplo false belief task as to whether they reflect evidence for understanding or merely exhibit a difference in guessing rate. We found (a) a greater variability of response types in both Duplo tasks, (b) no evidence that responses in the Duplo tasks reveal earlier competence than those in the standard false belief test, and (c) a reassuring correlation between false belief tasks, suggesting that the Duplo task does pick up understanding of belief in light of the standard test.

The social foundation of executive function

In this study, we propose that infant social cognition may 'bootstrap' the successive development of domain-general cognition in line with the cultural intelligence hypothesis. Using a longitudinal design, 6-month-old infants (N = 118) were assessed on two basic social cognitive tasks targeting the abilities to share attention with others and understanding other peoples' actions. At 10 months, we measured the quality of the child's social learning environment, indexed by parent's abilities to provide scaffolding behaviors during a problem-solving task. Eight months later, the children were followed up with a cognitive test-battery, including tasks of inhibitory control and working memory. Our results showed that better infant social action understanding interacted with better parental scaffolding skills in predicting simple inhibitory control in toddlerhood. This suggests that infants' who are better at understanding other's actions are also better equipped to make the most of existing social learning opportunities, which in turn may benefit future non-social cognitive outcomes.

Fourteen-month-old infants track the language comprehension of communicative partners

Infants employ sophisticated mechanisms to acquire their first language, including some that rely on taking the perspective of adults as speakers or listeners. When do infants first show awareness of what other people understand? We tested 14‐month‐old infants in two experiments measuring event‐related potentials. In Experiment 1, we established that infants produce the N400 effect, a brain signature of semantic violations, in a live object naming paradigm in the presence of an adult observer. In Experiment 2, we induced false beliefs about the labeled objects in the adult observer to test whether infants keep track of the other person's comprehension. The results revealed that infants reacted to the semantic incongruity heard by the other as if they encountered it themselves: they exhibited an N400‐like response, even though labels were congruous from their perspective. This finding demonstrates that infants track the linguistic understanding of social partners.

The relationship between parental mental-state language and 2.5-year-olds' performance on a nontraditional false-belief task

A growing body of evidence suggests that children succeed in nontraditional false-belief tasks in the first years of life. However, few studies have examined individual differences in infants' and toddlers' performance on these tasks. Here we investigated whether parental use of mental-state language (i.e. think, understand), which predicts children's performance on elicited-response false-belief tasks at older ages, also predicts toddlers' performance on a nontraditional task. We tested 2.5-year-old children in a verbal nontraditional false-belief task that included two looking time measures, anticipatory looking and preferential looking, and measured parents' use of mental-state language during a picture-book task. Parents' use of mental-state language positively predicted children's performance on the anticipatory-looking measure of the nontraditional task. These results provide the first evidence that social factors relate to children's false-belief understanding prior to age 3 and that this association extends to performance on nontraditional tasks. These findings add to a growing number of studies suggesting that mental-state language supports mental-state understanding across the lifespan.

How do 3-month-old infants attribute preferences to a human agent?

The current study showed that 3-month-old infants attributed a preference to a human agent, with her face and upper body visible, when she consistently reached for and grasped one of two objects with her bare hand. In contrast, infants did not appear to interpret the agent's same actions of grasping the object as indicative of her preference when it was the only object present or when it hid the other object from her but not from the infants. These results suggest that even from an early age, infants interpret human agents' actions in terms of mental states such as goals and preferences. In light of the current results, mechanisms for early psychological understanding are discussed.

Helping as an early indicator of a theory of mind: Mentalism or Teleology?

This article challenges the claim that young children's helping responses in Buttelmann, Carpenter, and Tomasello's (2009) task are based on ascribing a false belief to a mistaken agent. In our first Study 18- to 32-month old children (N = 28) were more likely to help find a toy in the false belief than in the true belief condition. In Study 2, with 54 children of the same age, we assessed the authors' mentalist interpretation of this result against an alternative teleological interpretation that does not make the assumption of belief ascription. The data speak in favor of our alternative. Children's social competency is based more on inferences about what is likely to happen in a particular situation and on objective reasons for action than on inferences about agents' mental states. We also discuss the need for testing serious alternative interpretations of claims about early belief understanding.

Functional Organization of the Temporal-Parietal Junction for Theory of Mind in Preverbal Infants: A Near-Infrared Spectroscopy Study

Successful human social life requires imagining what others believe or think to understand and predict behavior. This ability, often referred to as theory of mind (ToM), reliably engages a specialized network of temporal and prefrontal brain regions in older children and adults, including selective recruitment of the temporal-parietal junction (TPJ). To date, how and when this specialized brain organization for ToM arises is unknown due to limitations in functional neuroimaging at younger ages. Here, we used the emerging technique of functional near-infrared spectroscopy to measure the functional brain response across parietal, temporal, and prefrontal regions in 7-month-old male and female infants as they viewed different video scenarios of a person searching for a hidden object. Over different conditions, we manipulated whether the person held an accurate (true) or inaccurate (false) belief about the location of the hidden object in the videos. In two separate experiments, we observed that activity from the TPJ, but not other temporal and prefrontal regions, spontaneously tracked with the beliefs of the other person, responding more during scenarios when the other person's belief regarding the location of the object was false compared with scenarios when her belief was true. These results mirror those obtained with adults to show that the TPJ already shows some functional organization relevant to high-level social cognition by around 7 months of age. Furthermore, these results suggest that infants may draw on similar core mechanisms to implicitly track beliefs, as adults do when reasoning explicitly about them.SIGNIFICANCE STATEMENT Humans selectively engage a network of brain regions, including the temporal-parietal junction (TPJ), to track what others think, an ability referred to as theory of mind. How and when this specialized brain organization for high-level social cognition arises is unknown. Using the emerging technique of near-infrared spectroscopy with 7-month-old infants, we observed that activity of the TPJ, but not other temporal and frontal regions, distinguished between scenarios when another person's belief about the location of the object was false compared with scenarios when the belief was true. These results suggest that a basic neural architecture to understand and predict the actions of others based on their beliefs may be present from the first year of life.

Turning the tide: A plea for cognitively lean interpretations of infant behaviour

Keven & Akins (K&A) revisit the controversial subject of neonatal imitation through analysing the physiological foundations of neonatal spontaneous behaviour. Consequently, they regard imitative capacities in neonates as unlikely. We welcome this approach as an overdue encouragement to refuse cognitively rich interpretations as far as cognitively lean interpretations are conceivable, and apply this rationale to other phenomena in early childhood development.

Revisiting Young Children's Understanding of the Psychological Causes of Behavior

In 1989, Miller and Aloise challenged the prevailing belief that preschoolers tend to explain others' behavior in terms of external events or a person's physical attributes and have little understanding of psychological causes. That review documented preschoolers' understanding of, and even preference for, psychological causes as part of an emerging renaissance in developmental social-cognitive research. The present, updated review (97 articles, participant ages 3 months to 6 years) suggests the emergence of a transformative new perspective in which social-cognition is balanced between social and cognitive aspects rather than tilted toward cognition. Recent research on infants' awareness of mental states, young children's understanding of social categories and their judgments of the trustworthiness of informants, and cultural context reveals various ways in which preschoolers' social-causal reasoning is social.

The Developmental Origins of False-Belief Understanding

Understanding that individuals can be mistaken, or hold false beliefs, about the world is an important human ability that plays a vital role in social interactions. When and how does this ability develop? Traditional investigations using elicited-response tasks suggested that false-belief understanding did not emerge until at least age 4. However, more recent studies have shown that children demonstrate false-belief understanding much earlier when tested via other means. In the present article, I summarize recent evidence that a robust, flexible understanding of false belief emerges in infancy and discuss why older children fail elicited-response tasks despite their ability to represent beliefs.

Reaction time profiles of adults' action prediction reveal two mindreading systems

Human beings are able to quickly step into others' shoes to predict peoples' actions. There is little consensus over how this cognitive feat might be accomplished. We tested the hypotheses that an efficient, but inflexible, mindreading system gives rise to appropriate reaction time facilitation in a standard unexpected transfer task, but not in a task involving an identity component. We created a new behavioural paradigm where adults had to quickly select whether an actor would reach, or not reach, for an object based on the actor's false belief about the object's location. By manipulating the type of object we compared participants' responding behaviour when they did and did not have to take the actor's perspective into account. While the overall accuracy reflected a high level of flexible belief reasoning across both tasks, the pattern of response times across conditions revealed a limit in the processing scope of an efficient mindreading system. Thus, we show, for the first time, that there are indeed different profiles of reaction times for object-location scenarios and for object-identity scenarios. The results elevate growing evidence that adult humans have not one, but two mindreading systems for dealing with mental states that underlie action.

Surprise! 20-month-old infants understand the emotional consequences of false beliefs

Recent studies suggest that by the second year of life, infants can attribute false beliefs to agents. However, prior studies have largely focused on infants' ability to predict a mistaken agent's physical actions on objects. The present research investigated whether 20-month-old infants could also reason about belief-based emotional displays. In Experiments 1 and 2, infants viewed an agent who shook two objects: one rattled and the other was silent. Infants expected the agent to express surprise at the silent object if she had a false belief that both objects rattled, but not if she was merely ignorant about the objects' properties. Experiment 3 replicated and extended these findings: if an agent falsely believed that two containers held toy bears (when only one did so), infants expected the agent to express surprise at the empty, but not the full, container. Together, these results provide the first evidence that infants in the second year of life understand the causal relationship between beliefs and emotional displays. These findings thus provide new evidence for false-belief understanding in infancy and suggest that infants, like older children, possess a robust understanding of belief that applies to a broad range of belief-based responses.

Two-and-a-half-year-olds succeed at a traditional false-belief task with reduced processing demands

When tested with traditional false-belief tasks, which require answering a standard question about the likely behavior of an agent with a false belief, children perform below chance until age 4 y or later. When tested without such questions, however, children give evidence of false-belief understanding much earlier. Are traditional tasks difficult because they tap a more advanced form of false-belief understanding (fundamental-change view) or because they impose greater processing demands (processing-demands view)? Evidence that young children succeed at traditional false-belief tasks when processing demands are reduced would support the latter view. In prior research, reductions in inhibitory-control demands led to improvements in young children's performance, but often only to chance (instead of below-chance) levels. Here we examined whether further reductions in processing demands might lead to success. We speculated that: (i) young children could respond randomly in a traditional low-inhibition task because their limited information-processing resources are overwhelmed by the total concurrent processing demands in the task; and (ii) these demands include those from the response-generation process activated by the standard question. This analysis suggested that 2.5-y-old toddlers might succeed at a traditional low-inhibition task if response-generation demands were also reduced via practice trials. As predicted, toddlers performed above chance following two response-generation practice trials; toddlers failed when these trials either were rendered less effective or were used in a high-inhibition task. These results support the processing-demands view: Even toddlers succeed at a traditional false-belief task when overall processing demands are reduced.

Predictive action tracking without motor experience in 8-month-old infants

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Can infants predictively track the kinematics of actions outside their motor repertoire?

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Pre-walking infants predictively tracked upright, but not inverted stepping actions.

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Sensorimotor cortex was activated more when infants observed upright stepping actions.

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Motor experience is not necessary for predictive tracking of action kinematics.

A popular idea in cognitive neuroscience is that to predict others’ actions, observers need to map those actions onto their own motor repertoire. If this is true, infants with a relatively limited motor repertoire should be unable to predict actions with which they have no previous motor experience. We investigated this idea by presenting pre-walking infants with videos of upright and inverted stepping actions that were briefly occluded from view, followed by either a correct (time-coherent) or an incorrect (time-incoherent) continuation of the action (Experiment 1). Pre-walking infants looked significantly longer to the still frame after the incorrect compared to the correct continuations of the upright, but not the inverted stepping actions. This demonstrates that motor experience is not necessary for predictive tracking of action kinematics. In a follow-up study (Experiment 2), we investigated sensorimotor cortex activation as a neural indication of predictive action tracking in another group of pre-walking infants. Infants showed significantly more sensorimotor cortex activation during the occlusion of the upright stepping actions that the infants in Experiment 1 could predictively track, than during the occlusion of the inverted stepping actions that the infants in Experiment 1 could not predictively track. Taken together, these findings are inconsistent with the idea that motor experience is necessary for the predictive tracking of action kinematics, and suggest that infants may be able to use their extensive experience with observing others’ actions to generate real-time action predictions.