Three-month-old infants attribute goals to a non-human agent

The present research examined whether 3-month-old infants, the youngest found so far to engage in goal-related reasoning about human agents, would also act as if they attribute goals to a novel non-human agent, a self-propelled box. In two experiments, the infants seemed to have interpreted the box’s actions as goal-directed after seeing the box approach object A as opposed to object B during familiarization. They thus acted as though they expected the box to maintain this goal and responded with increased attention when the box approached object B during test. In contrast, when object B was absent during familiarization and introduced afterwards, the infants’ responses were consistent with their having recognized that they had no information to predict which of the two objects the box should choose during test and therefore responded similarly when the box approached either object. However, if object B was absent during familiarization and object A was in different positions but the box persistently approached it, thus demonstrating equifinal variations in its actions, the infants again acted as though they attributed to the box a goal directed towards object A and expected the box to maintain this goal even when object B was introduced and hence responded with prolonged looking when the box failed to do so during test. These results are consistent with the notion that (a) infants as young as 3 months appear to attribute goals to both human and non-human agents, and (b) even young infants can use certain behavioral cues, e.g. equifinal variations in agents’ actions, to make inferences about agents’ goals.     

Actors and actions: The role of agent behavior in infants' attribution of goals

Twelve-month-old infants attribute goals to both familiar, human agents and unfamiliar, non-human agents. They also attribute goal-directedness to both familiar actions and unfamiliar ones. Four conditions examined information 12-month-olds use to determine which actions of an unfamiliar agent are goal-directed. Infants who witnessed the agent interact contingently with a human confederate encoded the agent's actions as goal-directed; infants who saw a human confederate model an intentional stance toward the agent without the agent's participation, did not. Infants who witnessed the agent align itself with one of two potential targets before approaching that target encoded the approach as goal-directed; infants who did not observe the self-alignment did not encode the approach as goal-directed. A possible common underpinning of these two seemingly independent sources of information is discussed.     

Beyond the information given: Infants’ transfer of actions learned through imitation

Five experiments were conducted to investigate infants’ ability to transfer actions learned via imitation to new objects and to examine what components of the original context are critical to such transfer. Infants of 15 months observed an experimenter perform an action with one or two toys and then were offered a novel toy that was not demonstrated for them. In all experiments, infants performed target actions with the novel toy more frequently than infants who were offered the same toy but had seen no prior demonstrations. Infants exhibited transfer even when the specific part to be manipulated looked different across the toys, even when they had not performed the actions with the demonstration toys themselves, even when the actions produced no effects on the demonstrations, and even when the actions were demonstrated with only a single exemplar toy. Transfer was especially robust when infants not only observed but also practiced the target actions on the demonstration trials. Learning action affordances (“means”) seems to be a central aspect of human imitation, and the propensity to apply these learned action affordances in new object contexts may be an important basis for technological innovation and invention.     

Goal saliency boosts infants’ action prediction for human manual actions,but not for mechanical claws

Previous research indicates that infants’ prediction of the goals of observed actions is influenced by own experience with the type of agent performing the action (i.e., human hand vs. non-human agent) as well as by action-relevant features of goal objects (e.g., object size). The present study investigated the combined effects of these factors on 12-month-olds’ action prediction. Infants’ (N = 49) goal-directed gaze shifts were recorded as they observed 14 trials in which either a human hand or a mechanical claw reached for a small goal area (low-saliency goal) or a large goal area (high-saliency goal). Only infants who had observed the human hand reaching for a high-saliency goal fixated the goal object ahead of time, and they rapidly learned to predict the action goal across trials. By contrast, infants in all other conditions did not track the observed action in a predictive manner, and their gaze shifts to the action goal did not change systematically across trials. Thus, high-saliency goals seem to boost infants’ predictive gaze shifts during the observation of human manual actions, but not of actions performed by a mechanical device. This supports the assumption that infants’ action predictions are based on interactive effects of action-relevant object features (e.g., size) and own action experience.     

Calculating the attentional orientation of an unfamiliar agent in infancy

By the end of the first year, infants are able to recognize both goal-directed and perceptually guided behavior in the actions of non-human agents, even faceless ones. How infants derive the relevant orientation of an unfamiliar agent in the absence of familiar markers such as eyes, ears, or face is unknown. The current studies tested the hypothesis that infants’ calculate an agent's “front” from the geometry of its behavior in the spatial environment. In the first study, 14–15-month-old infants observed a symmetrical, faceless agent either interact contingently with a confederate or act randomly. It then turn toward one of two target objects. Infants were more likely to look in the direction the agent turned than the opposite direction, but only in the contingent condition. In the second study, the location of the confederate and target objects was varied, which in turn influenced which end of the agent infants interpreted as the front. Finally, implications for infants’ early gaze-following behaviors with humans are tested and implications for theory of mind development more broadly are discussed.     

The attribution of attention: 9-month-olds' interpretation of gaze as goal-directed action

The current study distinguishes between attributions of goal-directed perception (i.e. attention) and non-goal-directed perception to examine 9-month-olds' interpretation of others' head and eye turns. In a looking time task, 9-month-olds encoded the relationship between an actor's head and eye turns and a target object if the head and eye turns were embedded in a sequence of multiple, variable actions with equifinal outcomes, but not otherwise. This evidence supports the claim that infants of this age may attribute perception, at least goal-directed perception, to others and undermines arguments that gaze-following at this age consists only of uninterpreted reflexes. The evidence also suggests alternative interpretations of the typical errors infants make in standard gaze-following procedures. Implications for infants' understanding of perception and attention in both human and non-human agents are discussed.     

Deferred imitation in 18-month-olds from two cultural contexts: The case of Cameroonian Nso farmer and German-middle class infants

Imitative learning has been described in naturalistic studies for different cultures, but lab-based research studying imitative learning across different cultural contexts is almost missing. Therefore, imitative learning was assessed with 18-month-old German middle-class and Cameroonian Nso farmer infants – representing two highly different eco-cultural contexts associated with different cultural models, the psychological autonomy and the hierarchical relatedness – by using the deferred imitation paradigm. Study 1 revealed that the infants from both cultural contexts performed a higher number of target actions in the deferred imitation than in the baseline phase. Moreover, it was found that German middle-class infants showed a higher mean imitation rate as they performed more target actions in the deferred imitation phase compared with Cameroonian Nso farmer infants. It was speculated that the opportunity to manipulate the test objects directly after the demonstration of the target actions could enhance the mean deferred imitation rate of the Cameroonian Nso farmer infants which was confirmed in Study 2. Possible explanations for the differences in the amount of imitated target actions of German middle-class and Cameroonian Nso farmer infants are discussed considering the object-related, dyadic setting of the imitation paradigm with respect to the different learning contexts underlying the different cultural models of learning.     

TOWARD A MENTALISTIC ACCOUNT OF EARLY PSYCHOLOGICAL REASONING

Recent investigations of early psychological understanding have revealed three key findings. First, young infants attribute goals and dispositions to any entity they perceive as an agent, whether human or non-human. Second, when interpreting an agent's actions in a scene, young infants take into account the agent's representation of the scene, even if this representation is less complete than their own. Third, at least by the second year of life, infants recognize that agents can hold false beliefs about a scene. Together, these findings support a system-based, mentalistic account of early psychological reasoning.     

The reliability of a model influences 14-month-olds’ imitation

Human infants have an enormous amount to learn from others to become full-fledged members of their culture. Thus, it is important that they learn from reliable, rather than unreliable, models. In two experiments, we investigated whether 14-month-olds (a) imitate instrumental actions and (b) adopt the individual preferences of a model differently depending on the model’s previous reliability. Infants were shown a series of videos in which a model acted on familiar objects either competently or incompetently. They then watched as the same model demonstrated a novel action on an object (imitation task) and preferentially chose one of two novel objects (preference task). Infants’ imitation of the novel action was influenced by the model’s previous reliability; they copied the action more often when the model had been reliable. However, their preference for one of the novel objects was not influenced by the model’s previous reliability. We conclude that already by 14 months of age, infants discriminate between reliable and unreliable models when learning novel actions.     

Let’s get it together: Infants generate visual predictions based on collaborative goals

Infants engage in social interactions that include multiple partners from very early in development. A growing body of research shows that infants visually predict the outcomes of an individual’s intentional actions, such as a person reaching towards an object (e.g., Krogh-Jespersen & Woodward, 2014), and even show sophistication in their predictions regarding failed actions (e.g., Brandone, Horwitz, Aslin, & Wellman, 2014). Less is known about infants’ understanding of actions involving more than one individual (e.g., collaborative actions), which require representing each partners’ actions in light of the shared goal. Using eye-tracking, Study 1 examined whether 14-month-old infants visually predict the actions of an individual based on her previously shared goal. Infants viewed videos of two women engaged in either a collaborative or noncollaborative interaction. At test, only one woman was present and infants’ visual predictions regarding her future actions were measured. Fourteen-month-olds anticipated an individual’s future actions based on her past collaborative behavior. Study 2 revealed that 11-month-old infants only visually predict higher-order shared goals after engaging in a collaborative intervention. Together, our results indicate that by the second year after birth, infants perceive others’ collaborative actions as structured by shared goals and that active engagement in collaboration strengthens this understanding in young infants.     

Mediated imitation in 6-month-olds: remembering by association

In two experiments with 72 6-month-olds, we examined whether associating an imitation task with an operant task affects infants' memory for either task. In Experiment 1, infants who imitated target actions that were modeled for 60 s on a hand puppet remembered them for only 1 day. We hypothesized that if infants associated the puppet imitation task with a longer-remembered operant task, then they might remember it longer too. In Experiment 2, infants learned to press a lever to activate a miniature train-a task 6-month-olds remember for 2 weeks-and saw the target actions modeled immediately afterward. These infants successfully imitated for up to 2 weeks, but only if the train memory was retrieved first. A follow-up experiment revealed that the learned association was bidirectional. This is the first demonstration of mediated imitation in 6-month-olds across two very different paradigms and reveals that associations are an important means of protracting memories.     

Does texting interrupt imitation learning in 19-month-old infants?

Observed disruptions to parent-child interactions during parental media use, such as texting, have been termed technoference. For example, when a language learning interaction was disrupted by a phone call, toddlers were less likely to acquire the word. Other studies demonstrated that parents often exhibit a still face while silently reading information on their cell phones. In the present study, the effect of a text interruption on infant imitation learning was examined. Parents demonstrated three target actions to their infants and then infants were given the opportunity to repeat those interactions. The actions were demonstrated four times. Text interruptions occurred before or between demonstrations. Performance of these groups was compared to a baseline control group where the infant did not see a demonstration of the target actions and a no-interruption group where the parents demonstrated the target actions four times without interruption. Parents were randomly assigned to three conditions, interruption-first condition, one-interruption condition, or three-interruptions condition. Infant behavior was measured during the interruptions. Across text interruption groups parents exhibited high levels of still face during the interruptions (77 %). However, infants in all 3 interruption groups performed significantly above the baseline control indicating learning despite the interruptions. Higher reported maternal reliance on the smartphone was related to poorer imitation performance overall. In contrast, when parents reported that they found it easier to multi-task infant imitation rates were higher. These findings indicate that infants can learn under conditions of brief technoference and that individual differences in family media ecology are associated with learning.     

When do we simulate non-human agents? Dissociating communicative and non-communicative actions

There is strong evidence that we automatically simulate observed behavior in our motor system. Previous research suggests that this simulation process depends on whether we observe a human or a non-human agent. Measuring a motor priming effect, this study investigated the question of whether agent-sensitivity of motor simulation depends on the specific action observed. Participants saw pictures depicting end positions of different actions on a screen. All postures featured either a human or non-human agent. Participants had to produce the matching action with their left or right hand depending on the hand presented on the screen. Three different actions were displayed: a communicative action (emblem), a transitive (goal-directed) action and an intransitive action. We found motor priming effects of similar size for human and non-human agents for transitive and intransitive actions. However, the motor priming effect for communicative actions was present for the human agent, but absent for the non-human agent. These findings suggest that biological tuning of motor simulation is highly action-selective and depends on whether the observed behavior appears to be driven by a reasonable goal.     

The Influence of Visually Dangerous Information on Imitation in Children

Abstract

Previous studies have demonstrated that when perceiving the actions of another agent, individuals will automatically imitate those observed actions. This study investigated how children’s imitation of physical actions was influenced by either visually neutral or visually dangerous information. Participants were presented with a series of pictures in which an agent was reaching towards either a neutral object or a dangerous object. Results showed that the imitation effect occurred when the agent was observed reaching and grasping a neutral object. However, this effect was not present when the agent’s hand was observed reaching towards or grasping, the non-handle side of a dangerous object. These results suggest children can predict potential behavioral consequences and adjust their imitative action depending on the perceived danger of the action.     

I don't get you. Action observation effects inverted by kinematic variation

Recent studies have reported an intricate interplay between affordance and mirror effects (the imitation of another agent) when participants attend to the concurrent presentation of an object and another agent interacting with it. In the present paper, we compare two experimental settings in which an observed action was presented as a prime for a task involving the categorization of a graspable object. In experiment 1a, the action depicted a reach and grasp gesture whereas in experiment 1b, only the reach phase was presented. This modification led to very different outcomes. Experiment 1a reflected the traditional imitation effect elicited by human motion. Conversely, experiment 1b showed the facilitation of contralateral responses. Affordance effects were found in experiment 1a only for the RVF. Our results support the view that motor simulation processes underlying imitation or joint actions are extremely sensitive to specific phase kinematics.     

Infants’ perception of goal-directed actions: A multi-lab replication reveals that infants anticipate paths and not goals

Influential developmental theories claim that infants rely on goals when visually anticipating actions. A widely noticed study suggested that 11-month-olds anticipate that a hand continues to grasp the same object even when it swapped position with another object (Cannon, E., & Woodward, A. L. (2012). Infants generate goal-based action predictions. Developmental Science, 15, 292–298.). Yet, other studies found such flexible goal-directed anticipations only from later ages on. Given the theoretical relevance of this phenomenon and given these contradicting findings, the current work investigated in two different studies and labs, whether infants indeed flexibly anticipate an action goal. Study 1 (N = 144) investigated by means of five experiments, under which circumstances (e.g., animated agent, human agent) 12-month-olds show flexible goal anticipation abilities. Study 2 (N = 104) presented 11-, 32-month-olds and adults both a human grasping action as well as a non-human action. In none of the experiments did infants flexibly anticipate the action based on the goal, but rather on the movement path, irrespective of the type of agent. Although one experiment contained a direct replication of Cannon and Woodward (2012), we were not able to replicate their findings. Overall our work challenges the view that infants are able to flexibly anticipate action goals from early on, but rather rely on movement patterns when processing other’s actions.     

Relations between 18-month-olds’ gaze pattern and target action performance: A deferred imitation study with eye tracking

Deferred imitation studies are used to assess infants’ declarative memory performance. These studies have found that deferred imitation performance improves with age, which is usually attributed to advancing memory capabilities. Imitation studies, however, are also used to assess infants’ action understanding. In this second research program it has been observed that infants around the age of one year imitate selectively, i.e., they imitate certain kinds of target actions and omit others. In contrast to this, two-year-olds usually imitate the model's exact actions. 18-month-olds imitate more exactly than one-year-olds, but more selectively than two-year-olds, a fact which makes this age group especially interesting, since the processes underlying selective vs. exact imitation are largely debated. The question, for example, if selective attention to certain kinds of target actions accounts for preferential imitation of these actions in young infants is still open. Additionally, relations between memory capabilities and selective imitation processes, as well as their role in shaping 18-month-olds’ neither completely selective, nor completely exact imitation have not been thoroughly investigated yet. The present study, therefore, assessed 18-month-olds’ gaze toward two types of actions (functional vs. arbitrary target actions) and the model's face during target action demonstration, as well as infants’ deferred imitation performance. Although infants’ fixation times to functional target actions were not longer than to arbitrary target actions, they imitated the functional target actions more frequently than the arbitrary ones. This suggests that selective imitation does not rely on selective gaze toward functional target actions during the demonstration phase. In addition, a post hoc analysis of interindividual differences suggested that infants’ attention to the model's social-communicative cues might play an important role in exact imitation, meaning the imitation of both functional and arbitrary target actions.     

Can 9.5-month-old infants attribute to an agent a disposition to perform a particular action on objects?

The present research examined whether 9.5-month-old infants can attribute to an agent a disposition to perform a particular action on objects, and can then use this disposition to predict which of two new objects - one that can be used to perform the action and one that cannot - the agent is likely to reach for next. The infants first received familiarization trials in which they watched an agent slide either three (Experiments 1 and 3) or six (Experiment 2) different objects forward and backward on an apparatus floor. During test, the infants saw two new identical objects placed side by side: one stood inside a short frame that left little room for sliding, and the other stood inside a longer frame that left ample room for sliding. The infants who saw the agent slide six different objects attributed to her a disposition to slide objects: they expected her to select the "slidable" as opposed to the "unslidable" test object, and they looked reliably longer when she did not. In contrast, the infants who saw the agent slide only three different objects looked about equally when she selected either test object. These results add to recent evidence that infants in the first year of life can attribute dispositions to agents, and can use these dispositions to help predict agents' actions in new contexts.     

Age-related changes in deferred imitation between 6 and 9 months of age

Six- and 9-month-old human infants were tested in a deferred imitation paradigm in which an experimenter performed a single action with a novel object. Although infants of both ages imitated the action when tested immediately, only the 9-month-olds exhibited imitation after a 24-h delay.     

The origins of belief representation: Monkeys fail to automatically represent others’ beliefs

Young infants’ successful performance on false belief tasks has led several researchers to argue that there may be a core knowledge system for representing the beliefs of other agents, emerging early in human development and constraining automatic belief processing into adulthood. One way to investigate this purported core belief representation system is to examine whether non-human primates share such a system. Although non-human primates have historically performed poorly on false belief tasks that require executive function capacities, little work has explored how primates perform on more automatic measures of belief processing. To get at this issue, we modified Kovács et al. (2010)’s test of automatic belief representation to examine whether one non-human primate species—the rhesus macaque (Macaca mulatta)—is automatically influenced by another agent’s beliefs when tracking an object’s location. Monkeys saw an event in which a human agent watched an apple move back and forth between two boxes and an outcome in which one box was revealed to be empty. By occluding segments of the apple’s movement from either the monkey or the agent, we manipulated both the monkeys’ belief (true or false) and agent’s belief (true or false) about the final location of the apple. We found that monkeys looked longer at events that violated their own beliefs than at events that were consistent with their beliefs. In contrast to human infants, however, monkeys’ expectations were not influenced by another agent’s beliefs, suggesting that belief representation may be an aspect of core knowledge unique to humans.