One‐year‐old infants use teleological representations of actions productively

Two experiments investigated whether infants represent goal‐directed actions of others in a way that allows them to draw inferences to unobserved states of affairs (such as unseen goal states or occluded obstacles). We measured looking times to assess violation of infants' expectations upon perceiving either a change in the actions of computer‐animated figures or in the context of such actions. The first experiment tested whether infants would attribute a goal to an action that they had not seen completed. The second experiment tested whether infants would infer from an observed action the presence of an occluded object that functions as an obstacle. The looking time patterns of 12‐month‐olds indicated that they were able to make both types of inferences, while 9‐month‐olds failed in both tasks. These results demonstrate that, by the end of the first year of life, infants use the principle of rational action not only for the interpretation and prediction of goal‐directed actions, but also for making productive inferences about unseen aspects of their context. We discuss the underlying mechanisms that may be involved in the developmental change from 9 to 12 months of age in the ability to infer hypothetical (unseen) states of affairs in teleological action representations.     

Outcome producing potential influences twelve-month-olds’ interpretation of a novel action as goal-directed

Learning about a novel, goal-directed action is a complex process. It requires identifying the outcome of the action and linking the action to its outcome for later use in new situations to predict the action or to anticipate its outcome. We investigated the hypothesis that linking a novel action to a salient change in the environment is critical for infants to assign a goal to the novel action. We report a study in which we show that 12-month-old infants, who were provided with prior experience with a novel action accompanied with a salient visible outcome in one context, can interpret the same action as goal-directed even in the absence of the outcome in another context. Our control condition shows that prior experience with the action, but without the salient effect, does not lead to goal-directed interpretation of the novel action. We also found that, for the case of 9-month-olds infants, prior experience with the outcome producing potential of the novel action does not facilitate a goal-directed interpretation of the action. However, this failure was possibly due to difficulties with generalizing the learnt association to another context rather than with linking the action to its outcome.     

Infants’ understanding of everyday social interactions: A dual process account

Six- and 12-month-old infant’s eye movements were recorded as they observed feeding actions being performed in a rational or non-rational manner. Twelve-month-olds fixated the goal of these actions before the food arrived (anticipation); the latency of these gaze shifts being dependent (r = .69) on infants life experience being feed. In addition, 6- and 12-month-olds dilated their pupil during observation of non-rational feeding actions. This effect could not be attributed to light differences or differences in familiarity, but was interpreted to reflect sympathetic-like activity and arousal caused by a violation of infant’s expectations about rationality. We argue that evaluation of rationality requires less experience than anticipations of action goals, suggesting a dual process account of preverbal infants’ everyday action understanding.     

Understanding the experimenter's intention improves 16-month-olds’ observational learning of the use of a novel tool

Our aim was to investigate why 16-month-old infants fail to master a novel tool-use action via observational learning. We hypothesized that 16-month-olds’ difficulties may be due to not understanding the goal of the observed action. To test this hypothesis, we investigated whether showing infants an explicit demonstration of the goal of the action before demonstrating the action would improve observational learning compared with a classic demonstration of the target action. We examined 16-month-old infants who observed a tool-use action consisting of grasping a rake-like tool to retrieve an out-of-reach toy, under five conditions. Only when infants were shown the goal of the action before demonstration did they show some success.     

Twelve-month-old infants interpret action in context

Two experiments assessed infants' understanding that actions that occur in sequence may be related to an overarching goal. Experiment 1 tested whether embedding an ambiguous action (touching the lid of a box) in a sequence that culminated with an action infants readily construe as goal-directed (grasping a toy inside the box) would alter infants' construal of the ambiguous action. Having seen the ambiguous action in this context, infants later construed this action in isolation as being directed at the toy within the box. Experiment 2 tested whether infants related the two actions on the basis of the temporal or the causal relation between them. When the causal relation was disrupted but the temporal relation was preserved, infants no longer related the two actions. These findings indicate that 12-month-old infants relate single actions to overarching goals and that they do so by construing goal-directed action in a causal framework.     

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.     

Preverbal infants identify emotional reactions that are incongruent with goal outcomes

Identifying the goal of another agent’s action allows an observer to make inferences not only about the outcomes the agent will pursue in the future and the means to be deployed in a given context, but also about the emotional consequences of goal-related outcomes. While numerous studies have characterized the former abilities in infancy, expectations about emotions have gone relatively unexplored. Using a violation of expectation paradigm, we present infants with an agent who attains or fails to attain a demonstrated goal, and reacts with positive or negative affect. Across several studies, we find that infants’ attention to a given emotional display differs depending on whether that reaction is congruent with the preceding goal outcome. Specifically, infants look longer at a negative emotional display when it follows a completed goal compared to when it follows a failed goal. The present results suggest that infants’ goal representations support expectations not only about future actions but also about emotional reactions, and that infants in the first year of life can relate different emotional reactions to conditions that elicit them.     

Triadic interactions support infants’ emerging understanding of intentional actions

Infants’ understanding of the intentional nature of human action develops gradually across the first year of life. A key question is what mechanisms drive changes in this foundational social‐cognitive ability. The current studies explored the hypothesis that triadic interactions in which infants coordinate attention between a social partner and an object of mutual interest promote infants’ developing understanding of others as intentional agents. Infants’ spontaneous tendency to participate in triadic engagement was assessed in a semi‐structured play session with a researcher. Intentional action understanding was assessed by evaluating infants’ ability to visually predict the goal of an intentional reaching action. Study 1 (N = 88) revealed that 8‐ to 9‐month‐olds who displayed more bouts of triadic engagement showed better concurrent reasoning about the goal of an intentional reaching action. Study 2 (N = 114) confirmed these findings using a longitudinal design and demonstrated that infants who displayed more bouts of triadic engagement at 6–7 months were better at prospectively reasoning about the goal of an intentional reaching action 3 months later. Cross‐lagged path analyses revealed that intentional action understanding at 6–7 months did not predict later triadic engagement, suggesting that early triadic engagement supports later intentional action processing and not the other way around. Finally, evidence from both studies revealed the unique contribution of triadic over dyadic forms of engagement. These results highlight the importance of social interaction as a developmental mechanism and suggest that infants enrich their understanding of intentionality through triadic interactions with social partners.     

You Can't Always Get What You Want: Infants Understand Failed Goal-Directed Actions

ABSTRACT— At what age do infants understand that goals exist independently of the actions that result from them? Exploring infants' understanding of failed intentional actions—when the goal of the action is unfulfilled and thus not apparent in the actor's movements—is a critical step in answering this question. Using a visual habituation paradigm, we assessed when infants understand that a failed intentional action is goal directed and whether an understanding of successful intentional actions (actions that do overtly attain their goals) precedes an understanding of failed intentional actions. Results demonstrated that 10- and 12-month-olds recognized the goal directedness of both successful and failed reaching actions. Eight-month-olds also recognized the goal directedness of successful actions, but not of unsuccessful attempts. Thus, by the end of the 1st year of life, infants possess an impressive understanding of intentional action, and an understanding of failed intentional actions follows an earlier understanding of successful ones.     

The link between maternal interaction style and infant action understanding

The present study investigates whether the maternal interaction style is related to 6-month-old infants' action interpretation. We tested 6-month-olds ability to interpret an unfamiliar human action as goal-directed using a modified version of the paradigm used by Woodward, A. L. (1999). Infant's ability to distinguish between purposeful and non-purposeful behaviours. Infant Behavior & Development, 22, 145-160 and Király, I., Jovanovic, B., Prinz, W., Aschersleben, G., & Gergely, G. (2003). The early origins of goal attribution in infancy. Consciousness & Cognition, 12, 732-751. Additionally, all infants and their mothers participated in a free play situation to assess maternal interaction styles as measured by the CARE-Index. According to mothers' distinct interaction styles, infants were divided into three groups. Results suggest that at 6 months of age infants of mothers with a modestly controlling interaction style are better at interpreting a human action as goal-directed than infants of sensitive and relative unresponsive mothers. The ability to understand human action as goal-directed might be a corollary of an adaptive strategy in infancy.     

Ten‐month‐old infants use prior information to identify an actor's goal

For adults, prior information about an individual's likely goals, preferences or dispositions plays a powerful role in interpreting ambiguous behavior and predicting and interpreting behavior in novel contexts. Across two studies, we investigated whether 10‐month‐old infants’ ability to identify the goal of an ambiguous action sequence was facilitated by seeing prior instances in which the actor directly pursued and obtained her goal, and whether infants could use this prior information to understand the actor's behavior in a new context. Experiment 1 demonstrated that the goal preview impacted infants’ subsequent action understanding, but only if the preview was delivered in the same room as the subsequent action sequence. Experiment 2 demonstrated that infants’ failure to transfer prior goal information across situations arose from a change in the room per se and not other features of the task. Our results suggest that infants may use their understanding of simple actions as a leverage point for understanding novel or ambiguous actions, but that their ability to do so is limited to certain types of contextual changes.     

Six-and-a-half-month-old children positively attribute goals to human action and to humanoid-robot motion

Recent infant studies indicate that goal attribution (understanding of goal-directed action) is present very early in infancy. We examined whether 6.5-month-olds attribute goals to agents and whether infants change the interpretation of goal-directed action according to the kind of agent. We conducted three experiments using the visual habituation paradigm. In Experiment 1, we investigated whether 6.5-month-olds attribute goals to human action. In Experiment 2, we investigated whether 6.5-month-olds attribute goals to humanoid-robot motion. In Experiment 3, we tested whether infants attribute goals to a moving box. The agent used in Experiment 3 had no human-like appearance. The results of the three experiments show that infants positively attribute goals to both human action (Experiment 1) and humanoid motion (Experiment 2) but not to a moving box (Experiment 3). These results suggest that 6.5-month-olds tend to interpret certain actions in terms of goals, their reasoning about these actions is based on a sophisticated teleological representation, and that human-like appearance of agents may influence this teleological reasoning in early infancy.     

Eighteen- and 24-month-old infants correct others in anticipation of action mistakes

Much of human communication and collaboration is predicated on making predictions about others' actions. Humans frequently use predictions about others' action mistakes to correct others and spare them mistakes. Such anticipatory correcting reveals a social motivation for unsolicited helping. Cognitively, it requires forward inferences about others' actions through mental attributions of goal and reality representations. The current study shows that infants spontaneously intervene when an adult is mistaken about the location of an object she is about to retrieve. Infants pointed out a correct location for an adult before she was about to commit a mistake. Infants did not intervene in control conditions when the adult had witnessed the misplacement, or when she did not intend to retrieve the misplaced object. Results suggest that preverbal infants anticipate a person's mistaken action through mental attributions of both her goal and reality representations, and correct her proactively by spontaneously providing unsolicited information.     

Action experience alters 3-month-old infants' perception of others' actions

An intervention facilitated 3-month-old infants' apprehension of objects either prior to (reach first), or after (watch first) viewing another person grasp similar objects in a visual habituation procedure. Action experience facilitated action perception: reach-first infants focused on the relation between the actor and her goal, but watch-first infants did not. Infants' sensitivity to the actor's goal was correlated with their engagement in object-directed contact with the toys. These findings indicate that infants can rapidly form goal-based action representations and suggest a developmental link between infants' goal directed actions and their ability to detect goals in the actions of others.     

Infants' perception of goal‐directed actions on video

Imitation studies and object search studies show that infants have difficulties using action information presented on video to guide their own behaviour. The present study investigated whether infants also have problems interpreting information shown on video relative to real live information. It was examined whether 6‐month‐olds interpret an action with a salient action effect as goal‐directed when it is performed by an actor on a video‐screen and when it is performed by a live actor. A video presentation of a goal‐directed action display was presented to one group of infants, and another group received the same action display, matched in all details, live on a stage. Results indicate that 6‐month‐olds in the video group as well as in the live group interpreted the human action as goal‐directed. Moreover, comparison across both groups revealed no difference in the overall looking pattern between the video and the live presentation group. Thus, our findings show that infants as young as 6 months of age can take important information from video clips and interpret televised actions in meaningful ways that is equivalent to their interpretation of live actions.     

Emergent Goal-Anticipatory Gaze in Infants via Event-Predictive Learning and Inference

From about 7 months of age onward, infants start to reliably fixate the goal of an observed action, such as a grasp, before the action is complete. The available research has identified a variety of factors that influence such goal-anticipatory gaze shifts, including the experience with the shown action events and familiarity with the observed agents. However, the underlying cognitive processes are still heavily debated. We propose that our minds (i) tend to structure sensorimotor dynamics into probabilistic, generative event-predictive, and event boundary predictive models, and, meanwhile, (ii) choose actions with the objective to minimize predicted uncertainty. We implement this proposition by means of event-predictive learning and active inference. The implemented learning mechanism induces an inductive, event-predictive bias, thus developing schematic encodings of experienced events and event boundaries. The implemented active inference principle chooses actions by aiming at minimizing expected future uncertainty. We train our system on multiple object-manipulation events. As a result, the generation of goal-anticipatory gaze shifts emerges while learning about object manipulations: the model starts fixating the inferred goal already at the start of an observed event after having sampled some experience with possible events and when a familiar agent (i.e., a hand) is involved. Meanwhile, the model keeps reactively tracking an unfamiliar agent (i.e., a mechanical claw) that is performing the same movement. We qualitatively compare these modeling results to behavioral data of infants and conclude that event-predictive learning combined with active inference may be critical for eliciting goal-anticipatory gaze behavior in infants.     

Primacy of information about means selection over outcome selection in goal attribution by infants

It has been shown that, when observing an action, infants can rely on either outcome selection information (i.e., actions that express a choice between potential outcomes) or means selection information (i.e., actions that are causally efficient toward the outcome) in their goal attribution. However, no research has investigated the relationship between these two types of information when they are present simultaneously. In an experiment that addressed this question directly, we found that when outcome selection information could disambiguate the goal of the action (e.g., the action is directed toward one of two potential targets), but means selection information could not (i.e., the action is not efficiently adjusted to the situational constraints), 7- and 9-month-old infants did not attribute a goal to an observed action. This finding suggests that means selection information takes primacy over outcome selection information. The early presence of this bias sheds light on the nature of the notion of goal in action understanding.     

Infants Anticipate Others' Social Preferences

In the current eye‐tracking study, we explored whether 12‐month‐old infants can predict others' social preferences. We showed infants scenes in which two characters alternately helped or hindered an agent in his goal of climbing a hill. In a control condition, the two characters moved up and down the hill in identical ways to the helper and hinderer but did not make contact with the agent; thus, they did not cause him to reach or not reach his goal. Following six alternating familiarization trials of helping and hindering interactions (help–hinder condition) or up and down interactions (up–down condition), infants were shown one test trial in which they could visually anticipate the agent approaching one of the two characters. As predicted, infants in the help–hinder condition made significantly more visual anticipations toward the helping than hindering character, suggesting that they predicted the agent to approach the helping character. In contrast, infants revealed no difference in visual anticipations between the up and down characters. The up–down condition served to control for low‐level perceptual explanations of the results for the help–hinder condition. Thus, together the results reveal that 12‐month‐old infants make predictions about others' behaviour and social preferences from a third‐party perspective. Copyright © 2012 John Wiley & Sons, Ltd.     

Eighteen-month-olds integrate verbal cues into their action processing: Evidence from ERPs and mu power

Behavioral research has shown that infants use both behavioral cues and verbal cues when processing the goals of others’ actions. For instance, 18-month-olds selectively imitate an observed goal-directed action depending on its (in)congruence with a model’s previous verbal announcement of a desired action goal. This EEG-study analyzed the electrophysiological underpinnings of these behavioral findings on the two functional levels of conceptual action processing and motor activation. Mid-latency mean negative ERP amplitude and mu-frequency band power were analyzed while 18-month-olds (N = 38) watched videos of an adult who performed one out of two potential actions on a novel object. In a within-subjects design, the action demonstration was preceded by either a congruent or an incongruent verbally announced action goal (e.g., “up” or “down” and upward movement). Overall, ERP negativity did not differ between conditions, but a closer inspection revealed that in two subgroups, about half of the infants showed a broadly distributed increased mid-latency ERP negativity (indicating enhanced conceptual action processing) for either the congruent or the incongruent stimuli, respectively. As expected, mu power at sensorimotor sites was reduced (indicating enhanced motor activation) for congruent relative to incongruent stimuli in the entire sample. Both EEG correlates were related to infants’ language skills. Hence, 18-month-olds integrate action-goal-related verbal cues into their processing of others’ actions, at the functional levels of both conceptual processing and motor activation. Further, cue integration when inferring others’ action goals is related to infants’ language proficiency.     

Pulling out the intentional structure of action: the relation between action processing and action production in infancy

Adults and children readily construct action representations organized with respect to an ultimate goal. These representations allow one to predict the consequences of action, interpret and describe actions, and categorize action sequences. In this paper, we explore the ontogeny of hierarchically organized action representations, and its relation to infants' ability to produce similar sequences. To do so, we examine infants' perception and performance of a means-end sequence: pulling a cloth to retrieve a toy. Using a visual habituation paradigm, we demonstrate that 12-month-old infants understand that the initial step of the cloth-pulling sequence is directed toward the ultimate goal of attaining the toy, and use their knowledge of the causal constraints of the sequence to make this goal attribution. Ten-month-olds, however, appear transitional with respect to this understanding: their ability to identify the goal of the cloth-pulling sequence is related to their own ability to planfully solve a similar sequence. These findings are consistent with a burgeoning body of literature suggesting an intimate link between action production and perception, and suggest that this link is in place by at least 10 months of age.