How and why do infants imitate? An ideomotor approach to social and imitative learning in infancy (and beyond)

Spontaneous bodily coordination varies across affective and intellectual child-adult interactions

Research on child-adult interactions has identified that the morphology of bodily coordination seems to be sensitive to age and type of interaction. Mirror-like imitation emerges earlier in life and is more common during emotionally laden interactions, while anatomical imitation is acquired later and associated with cognitive tasks. However, it remains unclear whether these morphologies also vary with age and type of interaction during spontaneous coordination. Here we report a motion capture study comparing the spontaneous coordination patterns of thirty-five 3-year-old (20 girls; Mage = 3.15 years) and forty 6-year-old children (20 girls; Mage = 6.13 years) interacting with unacquainted adults during two storytelling sessions. The stories narrated the search of a character for her mother (Predominantly Affective Condition) or an object (Predominantly Intellectual Condition) inside a supermarket. Results show that children of both ages consistently coordinated their spontaneous movements towards adult storytellers, both in symmetric and asymmetric ways. However, symmetric coordination was more prominent in 3-year-old children and during predominantly emotional interactions, whereas asymmetric coordination prevailed in 6-year-old children and during predominantly intellectual interactions. These results add evidence from spontaneous interactions in favor of the hypothesis that symmetric coordination is associated with affective interactions and asymmetric coordination with intellectual ones.

Longitudinal evidence that infants develop their imitation abilities by being imitated

Humans are widely considered the most socially sophisticated species on the planet. Their remarkable abilities in navigating the social world have given rise to complex societies and the advancement of cultural intelligence.1,2,3,4,5 But what characterizes us as ultra-social beings? Theoretical advances in social sciences over the last century purport imitation as a central mechanism for the emergence of humans' unique social-cognitive abilities.6,7,8 Uncovering the ontogeny of imitation is therefore paramount for understanding human cultural evolution. Yet how humans become able to imitate is unclear and intensely debated. Recently, multidisciplinary findings have challenged long-standing assumptions that imitation is inborn.9,10,11,12 So what are the underlying processes supporting the development of imitation? One fascinating possibility is that infants become able to imitate by being imitated.13,14,15 Cognitive theories have suggested that by perceiving others imitating one's own behavior, visual and motor representations of that behavior are coactivated and associated, leading to the emergence of imitation abilities.14,15 Here, we show that being imitated by sensitive caregivers in infancy constitutes a psychological process giving rise to infants' imitation abilities. Results demonstrated (1) that maternal imitation at 14 months positively predicted infants' imitation abilities at 18 months and (2) that maternal imitation at 14 months mediated the positive effect of maternal sensitivity at 6 months on infants' imitation abilities at 18 months. This offers substantial evidence for the role of social interactions in the emergence of imitation as a key factor for human cultural learning.

3-4-year-old children’s memory flexibility allows adaptation to an altered context

Imitation provides a reliable method to investigate the developing memory functions in childhood. The present study explored whether 3-4-year-old children are able to revise their previous experiences after a 1 week delay in order to adapt to an altered context. We used a combined short-term (Session 1) and delayed (Session 2) imitation paradigm based on a previous study with 2-year-olds. The constraints (target object close/far) and relatedly the relevance of using a tool in a goal attainment task (irrelevant/relevant, respectively) changed between the sessions. We found that children in Session 1 used the tool only when it was needed (relevant/object far context). After the 1 week delay when the tool was previously irrelevant and then became relevant, children remembered the irrelevant act and applied it in the altered context. When the tool lost its relevance after 1 week, children used the tool less than before, but did not fully omit it, despite its reduced efficiency. The present data with 3-year-olds was compared to a pattern of results with 2-year-olds (from a similar previous study), that allowed to discuss possible developmental transitions in memory and imitation. We propose that the flexible restoration of a formerly irrelevant act and the maintenance of a formerly successful solution indicate flexibility of preschooler’s memory when guiding imitation. This flexibility, however, interacts with children’s tendency to remain faithful to strategies that were previously ostensively demonstrated to them.

Preschool children's use of perceptual-motor knowledge and hierarchical representational skills for tool making

Although other animals can make simple tools, the expanded and complex material culture of humans is unprecedented in the animal kingdom. Tool making is a slow and late-developing ability in humans, and preschool children find making tools to solve problems very challenging. This difficulty in tool making might be related to the lack of familiarity with the tools and may be overcome by children's long term perceptual-motor knowledge. Thus, in this study, the effect of tool familiarity on tool making was investigated with a task in which 5-to-6-year-old children (n = 75) were asked to remove a small bucket from a vertical tube. The results show that children are better at tool making if the tool and its relation to the task are familiar to them (e.g., soda straw). Moreover, we also replicated the finding that hierarchical complexity and tool making were significantly related. Results are discussed in light of the ideomotor approach.

The Embodied Crossmodal Self Forms Language and Interaction: A Computational Cognitive Review

Human language is inherently embodied and grounded in sensorimotor representations of the self and the world around it. This suggests that the body schema and ideomotor action-effect associations play an important role in language understanding, language generation, and verbal/physical interaction with others. There are computational models that focus purely on non-verbal interaction between humans and robots, and there are computational models for dialog systems that focus only on verbal interaction. However, there is a lack of research that integrates these approaches. We hypothesize that the development of computational models of the self is very appropriate for considering joint verbal and physical interaction. Therefore, they provide the substantial potential to foster the psychological and cognitive understanding of language grounding, and they have significant potential to improve human-robot interaction methods and applications. This review is a first step toward developing models of the self that integrate verbal and non-verbal communication. To this end, we first analyze the relevant findings and mechanisms for language grounding in the psychological and cognitive literature on ideomotor theory. Second, we identify the existing computational methods that implement physical decision-making and verbal interaction. As a result, we outline how the current computational methods can be used to create advanced computational interaction models that integrate language grounding with body schemas and self-representations.

Social learning of action-effect associations: Modulation of action control following observation of virtual action's effects

A core assumption of ideomotor theory is that learned bidirectional associations between actions and their effects enable agents to select and initiate actions by anticipating their sensory consequences. Although the acquisition of bidirectional action-effect (A-E) associations built on the experience of one's own movements has received considerable empirical support, the available evidence for A-E learning through the observation of others' actions and their effects remains limited. In two experiments, we tested whether A-E associations could be acquired through social learning in an experimental setup involving observation of virtual actions. In an acquisition phase, participants repeatedly observed finger movements on a screen, and each movement was consistently followed by a specific effect tone. In the subsequent test phase, tones were presented as imperative stimuli in a reaction-time task. In both experiments, reaction times were shorter when tones required the same response with which they had been linked in the preceding observation phase, compared with when they required a different response, revealing the impact of A-E associations acquired through observation. Similar results were obtained whether the movements observed during the acquisition phase were spatially aligned (Experiment 1) or not (Experiment 2) with participants' responses in the test phase, ruling out the possibility that the results merely reflect spatial compatibility effects. Our findings add new evidence for an acquisition of A-E associations through observation. Importantly, we generalize this acquisition process to the observation of virtual actions. These findings further confirm effect-based action control, as proposed by ideomotor theory.

Paying it back and forward: The impact of experiencing and observing others' sharing and stinginess on preschoolers' own sharing behavior and expectations

Recent research suggests that children's sharing behavior is affected by experiencing or observing others' sharing. These effects have been studied within research on the development of reciprocity and the effects of social modeling. In the current study, direct and indirect types of reciprocity and social modeling were assessed in 3- to 6-year-old children in three experiments (overall N = 382). In each experiment, we explored whether negative and positive social behavior were similarly paid back and forward in each of the different types of reciprocity. Moreover, we assessed the extent to which children reciprocated toward the protagonist who had performed the actual behavior and toward a neutral other. In Experiment 1, children experienced another's sharing behavior as recipients and could then allocate resources to this character and a neutral other. In Experiment 2, children observed another's sharing behavior and could then allocate resources to this character and a neutral other. In Experiment 3, children were asked to predict another protagonist's sharing in the same context as in Experiment 1. Overall, children treated the protagonist and the neutral other similarly and predicted others to do the same. Yet, they were more likely to reciprocate negative acts in indirect types of reciprocity. The results are interpreted with respect to the impact of observational learning and representational development on children's social behavior.

Enabling New Articulatory Gestures in Children With Persistent Speech Sound Disorders Using Ultrasound Visual Biofeedback

Purpose This study evaluated ultrasound visual biofeedback treatment for teaching new articulations to children with a wide variety of speech sound disorders. It was hypothesized that motor-based intervention incorporating ultrasound would lead to rapid acquisition of a range of target lingual gestures with generalization to untreated words. Method Twenty children aged 6-15 years with a range of mild to severe speech disorders affecting a variety of lingual targets enrolled in a case series with replication. Of these, 15 children completed the intervention. All of the children presented with a variety of errors. We therefore employed a target selection strategy to treat the most frequent lingual error. These individual speech targets were treated using ultrasound visual biofeedback as part of ten to twelve 1-hr intervention sessions. The primary outcome measure was percentage of target segments correct in untreated wordlists. Results Six children were treated for velar fronting; 3 children, for postalveolar fronting; 2 children, for backing alveolars to pharyngeal or glottal place; 1 child, for debuccalization (production of all onsets as [h]); 1 child, for vowel merger; and 2 children, for lateralized sibilants. Ten achieved the new articulation in the 1st or 2nd session of intervention, despite no children being readily stimulable for their target articulation before intervention. In terms of generalization, effect sizes for percentage of target segments correct ranged from no effect (5 children), small effect (1 child), medium effect (4 children), and large effect (5 children). Conclusions Ultrasound visual biofeedback can be used to treat a wide range of lingual errors in children with various speech sound disorders, from mild to severe. Visual feedback may be useful for establishing new articulations; however, generalization is more variable.

Entwicklung des Gedächtnisses bei präverbalen Kindern

Zusammenfassung. Gedächtnis ist eine elementare Fähigkeit, deren Entwicklungsverlauf insbesondere für das präverbale Alter bisher nicht eindeutig beschrieben ist. Zur Erfassung von Gedächtnisleistungen im präverbalen Alter werden verschiedene Verhaltensmaße herangezogen. Früheste Beobachtungen von Leistungen des impliziten Gedächtnisses sind über Präferenzverhalten in Paarvergleichs- und Habituationsaufgaben möglich und basieren auf einem Reizinformationsvergleich. Auch operant konditioniertes Verhalten in der Mobile- und Zug-Aufgabe indiziert eine implizite Gedächtnisleistung und basiert auf dem Lernen aus Konsequenzen. Imitationsverhalten als Leistung des expliziten Gedächtnissystems beruht auf Modelllernen in Aufgaben zur verzögerten Imitation. Sowohl im impliziten als auch im expliziten System sind im Entwicklungsverlauf Zuwächse der Gedächtnisleistungen hinsichtlich Kapazität, Behaltensdauer, Enkodiergeschwindigkeit und Flexibilität im Abruf beobachtbar. Die den Aufgaben zur Erfassung von Gedächtnisleistungen zugrundeliegenden Mechanismen deuten auf eine sukzessive Entwicklung zuerst des impliziten, dann des expliziten Systems hin.

Young Children's Motor Interference Is Influenced by Novel Group Membership

From early childhood onward, individuals use behavior copying to communicate liking and belonging. This non-verbal signal of affiliation is especially relevant in the context of social groups and indeed both children and adults copy in-group more than out-group members. Given the societal importance of inter-group interactions, it is imperative to understand the mechanistic level at which group modulations of copying occur early in development. The current study was designed to investigate the effect of novel group membership on young children’s motor behavior during a simultaneous movement-observation and -execution task. Four- to six-year-olds (n = 65) first gained membership to one of two novel groups based on their color preference and put on a vest in their chosen color. Subsequently, they were instructed to draw a straight line back-and-forth on a tablet computer that was concurrently displaying a stimulus video in which a model moved her arm congruently or incongruently to the child’s instructed direction. In half of the stimulus videos the model belonged to the in-group, while in the other half the model belonged to the out-group, as identified by the color of her dress. The deviations into the uninstructed direction of the children’s drawings were quantified as a measure of how much observing the models’ behaviors interfered with executing their own behaviors. The motor interference effect, namely higher deviations in the incongruent trials than in the congruent trials, was found only for the out-group condition. An additional manipulation of whether the models’ arms followed a biological or non-biological velocity profile had little effect on children’s motor interference. The results are interpreted in the context of the explicit coordinative nature of the task as an effect of heightened attention toward interacting with an out-group member. This study demonstrates that already during early childhood, novel group membership dynamically influences behavior processing as a function of interaction context.

Practicing Novel, Praxis-Like Movements: Physiological Effects of Repetition

Our primary goal was to develop and validate a task that could provide evidence about how humans learn praxis gestures, such as those involving the use of tools. To that end, we created a video-based task in which subjects view a model performing novel, meaningless one-handed actions with kinematics similar to praxis gestures. Subjects then imitated the movements with their right hand. Trials were repeated six times to examine practice effects. EEG was recorded during the task. As a control, subjects watched videos of a model performing a well-established (over learned) tool-use gesture. These gestures were also imitated six times. Demonstrating convergent validity, EEG measures of task-related cortical activation were similar in topography and frequency between the novel gesture task and the overlearned, praxis gesture task. As in studies assessing motor skill learning with simpler tasks, cortical activation during novel gesture learning decreased as the same gestures were repeated. In the control condition, repetition of overlearned tool-use gestures were also associated with reductions in activation, though to a lesser degree. Given that even overlearned, praxis gestures show constriction of EEG activity with repetition, it is possible that that attentional effects drive some of the repetition effects seen in EEG measures of activation during novel gesture repetition.

Clarifying the range of social-cognitive processes subserving human teaching

An evolutionary framework on human teaching is not well equipped to explain the nature of human teaching unless it specifies the subserving cognitive and motivational mechanisms. Only a theory that speculates on the psychological processes provides testable predictions and stimulates further empirical research.