Goals influence memory and imitation for dynamic human action in 36-month-old children

The role of semantic similarity in verb learning events: Vocabulary-related changes across early development

Verb meaning is challenging for children to learn across varied events. This study examined how the taxonomic semantic similarity of the nouns in novel verb learning events in a progressive alignment learning condition differed from the taxonomic dissimilarity of nouns in a dissimilar learning condition in supporting near (similar) and far (dissimilar) verb generalization to novel objects in an eye-tracking task. A total of 48 children in two age groups (23 girls; younger: 21-24 months, Mage = 22.1 months; older: 27-30 months: Mage = 28.3 months) who differed in taxonomic vocabulary size were tested. There were no group or learning condition differences in near generalization. The younger group demonstrated better far generalization of verbs learned with semantically dissimilar nouns. The older group demonstrated the opposite pattern, with better far generalization of verbs learned with semantically similar nouns in the progressive alignment condition. These patterns were associated with children's in-category vocabulary knowledge more than other vocabulary measures, including verb vocabulary size. Taxonomic vocabulary knowledge differentially affects verb learning and generalization across development.

The Development of Learning, Performing, and Controlling Repeated Sequential Actions in Young Children

Our daily lives are composed of several sequential actions that we perform routinely, such as making breakfast, taking a train, and changing clothes. Previous research has demonstrated that a routine system plays a role in performing and controlling repeated sequential actions in familiar situations, and a top-down control system involves the control of the routine system in novel situations. Specifically, most developmental studies have focused on the top-down control system (e.g., executive functions) as a factor enabling the control of goal-directed actions in novel situations. Yet, it has not been thoroughly examined how young children learn, perform, and control repeated sequential actions in familiar contexts. In this review, based on recent computational accounts for adults, we highlight two critical aspects of the routine system from a developmental perspective: (1) automatic flexible changes of contextual representations, which enables humans to select context-dependent actions appropriately; and (2) detection of deviant situations, which signals the need for control to avoid errors. In addition, we propose the developmental mechanism underlying the routine system and its potential driving factors such as statistical regularities and executive functions. Finally, we suggest that an investigation into the interplay between routine and executive functions can form foundations for understanding learning, performing, and controlling repeated sequential actions in young children and discuss future directions in this area.

Science with Duplo: Multilevel goal management in preschoolers' toy house constructions

Executing goal-directed action sequences is fundamental to our behavior. Planning and controlling these action sequences improves greatly over the preschool years. In this study, we examined preschoolers' ability to plan action sequences. A total of 69 3- to 5-year-olds were assessed on an action sequence planning task with a hierarchical goal structure and on several executive function tasks. Planning abilities improved with age. Improvements in inhibition were related to avoidance of actions irrelevant to the goal hierarchy. Updating skill appears to be associated with executing actions relevant to different subgoals. Using optical motion capture, we showed that children who followed the subgoals displayed less movement with their nonreaching hand within a subgoal. This effect was enhanced in children with better inhibitory skills, suggesting that such skills allow greater focus on executing the current subgoal. Thus, we provide evidence that structuring of subgoals in action sequence planning emerges during the preschool years and that improvements in performance in action sequence planning are related to executive functions.

Contribution of Executive Functions to Learning Sequential Actions in Young Children

This study examined whether executive functions impact how flexibly children represent task context in performing repeated sequential actions. Japanese children in Experiments 1 (N = 52; 3-6 years) and 2 (N = 50, 4-6 years) performed sequential actions repeatedly; one group received reminders. Experiment 1 indicated that reminders promote flexible changes in contextual representations. Experiment 2 observed such effects in younger children and showed executive functions were associated with the flexible representation of task context. Reminders did not perfectly compensate for the role of executive functions but wiped out individual differences in executive functions that contribute to children's acquisition of routines. Therefore, setting goals before context-dependent actions is necessary, but not sufficient, to modulate contextual representations in routines.

The flexibility of early memories: Limited reevaluation of action steps in 2-year-old infants

This study investigated the flexibility of 2-year-old infants' retrieval and reenactment processes. In a delayed imitation paradigm, children were exposed to a constraint change (implemented by the distance of a target object) affecting the relevance of using a tool to obtain a goal (reach the object). In Experiment 1, during demonstration in the first session the tool was either relevant or irrelevant for reaching the goal, and 1 week later it either lost or gained its relevance, respectively. We found that when the tool became unnecessary (relevant to irrelevant change), children used it somewhat less than before and used it less compared with when the tool's relevance remained the same (relevant to relevant, no change). When the tool became necessary after a constraint change (irrelevant to relevant change), children used the tool more than before, but not as much as in the Relevant-Relevant control condition. In Experiment 2, the timing of the constraint change (immediate or delayed) was varied in a modified version of the Irrelevant-Relevant condition, where practice before the constraint change was omitted. Children were not significantly more flexible in the immediate condition than in the delayed condition, and comparisons with Experiment 1 showed that performance did not change if we omitted the practice before the change. These results indicate that although 2-year-olds show considerable mnemonic performance, they face difficulties in adapting to constraint changes. We propose that this inflexibility may stem from infants' inability to revise their evaluations formed in previous events due to their immature episodic memory capacities.

Specialization in the vicarious learning of novel arbitrary sequences in humans but not orangutans

Sequence learning underlies many uniquely human behaviours, from complex tool use to language and ritual. To understand whether this fundamental cognitive feature is uniquely derived in humans requires a comparative approach. We propose that the vicarious (but not individual) learning of novel arbitrary sequences represents a human cognitive specialization. To test this hypothesis, we compared the abilities of human children aged 3-5 years and orangutans to learn different types of arbitrary sequences (item-based and spatial-based). Sequences could be learned individually (by trial and error) or vicariously from a human (social) demonstrator or a computer (ghost control). We found that both children and orangutans recalled both types of sequence following trial-and-error learning; older children also learned both types of sequence following social and ghost demonstrations. Orangutans' success individually learning arbitrary sequences shows that their failure to do so in some vicarious learning conditions is not owing to general representational problems. These results provide new insights into some of the most persistent discontinuities observed between humans and other great apes in terms of complex tool use, language and ritual, all of which involve the cultural learning of novel arbitrary sequences. This article is part of the theme issue 'Ritual renaissance: new insights into the most human of behaviours'.

Learning From Others: The Effects of Agency on Event Memory in Young Children

Little is known about the influence of social context on children's event memory. Across four studies, we examined whether learning that could occur in the absence of a person was more robust when a person was present. Three-year-old children (N = 125) viewed sequential events that either included or excluded an acting agent. In Experiment 1, children who viewed an agent recalled more than children who did not. Experiments 2a and 2b utilized an eye tracker to demonstrate this effect was not due to differences in attention. Experiment 3 used a combined behavioral and event-related potential paradigm to show that condition effects were present in memory-related components. These converging results indicate a particular role for social knowledge in supporting memory for events.

Can Young Children Ignore Irrelevant Events, or Subevents, During Verb Learning?

Children learning a verb may benefit from hearing it across situations (e.g., Behrend, 1995; Childers, 2011; Fisher et al, 1994; Pinker, 1989). At the same time, in everyday contexts, situations in which a verb is heard will be interrupted by distracting events. Using Structural Alignment theory as a framework (e.g., Gentner & Namy, 2006), Study 1 asks whether children can learn a verb when irrelevant, interleaved events are present. Two½- and 3½-year-old children saw dynamic events and were randomly assigned to one of three experimental conditions (differing in orders of events), or one of two control conditions. They extended the verbs in the experimental conditions, and not the control conditions. Three ½-year-olds were more successful than 2½-year-olds, though the younger children could extend verbs. A more difficult task is segmenting dynamic action into subevents that could be relevant for a verb (e.g., finding "chopping" in a cooking scene). In Study 2, 2½-, 3½- and 4½-year-old children were assigned to experimental conditions in which relevant events flowed into irrelevant events (or vice versa), or to a control. Two½-year-olds failed to extend the verbs at test, differing from the older children; children in experimental conditions extended the verbs while children in the control condition did not. Altogether, these results show children can ignore irrelevant events (and subevents), and extend new verbs by 3½ years. Results are important to understand learning in everyday contexts in which verbs are heard in varied situations over time.

A safety mechanism for observational learning

This empirical article presents the first evidence of a "safety mechanism" based on an observational-learning paradigm. It is accepted that during observational learning, a person can use different strategies to learn a motor skill, but it is unknown whether the learner is able to circumvent the encoding of an uncompleted observed skill. In this study, participants were tested in a dyadic protocol in which an observer watched a participant practicing two different motor sequences during a learning phase. During this phase, one of the two motor sequences was interrupted by a stop signal that precluded motor learning. The results of the subsequent retention test revealed that both groups learned the two motor sequences, but only the physical practice group showed worse performance for the interrupted sequence. The observers were consequently able to use a safety strategy to learn both sequences equally. Our findings are discussed in light of the implications of the action observation network for sequence learning and the cognitive mechanisms of error-based observation.

Children's Representation and Imitation of Events: How Goal Organization Influences 3-Year-Old Children's Memory for Action Sequences

Children's imitation of adults plays a prominent role in human cognitive development. However, few studies have investigated how children represent the complex structure of observed actions which underlies their imitation. We integrate theories of action segmentation, memory, and imitation to investigate whether children's event representation is organized according to veridical serial order or a higher level goal structure. Children were randomly assigned to learn novel event sequences either through interactive hands-on experience (Study 1) or via storybook (Study 2). Results demonstrate that children's representation of observed actions is organized according to higher level goals, even at the cost of representing the veridical temporal ordering of the sequence. We argue that prioritizing goal structure enhances event memory, and that this mental organization is a key mechanism of social-cognitive development in real-world, dynamic environments. It supports cultural learning and imitation in ecologically valid settings when social agents are multitasking and not demonstrating one isolated goal at a time.

Imitation by combination: preschool age children evidence summative imitation in a novel problem-solving task

Children are exceptional, even ‘super,’ imitators but comparatively poor independent problem-solvers or innovators. Yet, imitation and innovation are both necessary components of cumulative cultural evolution. Here, we explored the relationship between imitation and innovation by assessing children’s ability to generate a solution to a novel problem by imitating two different action sequences demonstrated by two different models, an example of imitation by combination, which we refer to as “summative imitation.” Children (N = 181) from 3 to 5 years of age and across three experiments were tested in a baseline condition or in one of six demonstration conditions, varying in the number of models and opening techniques demonstrated. Across experiments, more than 75% of children evidenced summative imitation, opening both compartments of the problem box and retrieving the reward hidden in each. Generally, learning different actions from two different models was as good (and in some cases, better) than learning from 1 model, but the underlying representations appear to be the same in both demonstration conditions. These results show that summative imitation not only facilitates imitation learning but can also result in new solutions to problems, an essential feature of innovation and cumulative culture.

Imitation as a mechanism in cognitive development: a cross-cultural investigation of 4-year-old children's rule learning

Children learn about the social and physical world by observing other people's acts. This experiment tests both Chinese and American children's learning of a rule. For theoretical reasons we chose the rule of categorizing objects by the weight. Children, age 4 years, saw an adult heft four visually-identical objects and sort them into two bins based on an invisible property-the object's weight. Children who saw this categorization behavior were more likely to sort those objects by weight than were children who saw control actions using the same objects and the same bins. Crucially, children also generalized to a novel set of objects with no further demonstration, suggesting rule learning. We also report that high-fidelity imitation of the adult's "hefting" acts may give children crucial experience with the objects' weights, which could then be used to infer the more abstract rule. The connection of perception, action, and cognition was found in children from both cultures, which leads to broad implications for how the imitation of adults' acts functions as a lever in cognitive development.

Becoming a high-fidelity - super - imitator: what are the contributions of social and individual learning?

In contrast to other primates, human children's imitation performance goes from low to high fidelity soon after infancy. Are such changes associated with the development of other forms of learning? We addressed this question by testing 215 children (26-59 months) on two social conditions (imitation, emulation) - involving a demonstration - and two asocial conditions (trial-and-error, recall) - involving individual learning - using two touchscreen tasks. The tasks required responding to either three different pictures in a specific picture order (Cognitive: Airplane→Ball→Cow) or three identical pictures in a specific spatial order (Motor-Spatial: Up→Down→Right). There were age-related improvements across all conditions and imitation, emulation and recall performance were significantly better than trial-and-error learning. Generalized linear models demonstrated that motor-spatial imitation fidelity was associated with age and motor-spatial emulation performance, but cognitive imitation fidelity was only associated with age. While this study provides evidence for multiple imitation mechanisms, the development of one of those mechanisms - motor-spatial imitation - may be bootstrapped by the development of another social learning skill - motor-spatial emulation. Together, these findings provide important clues about the development of imitation, which is arguably a distinctive feature of the human species.

Infant and adult visual attention during an imitation demonstration

Deferred imitation tasks have shown that manipulations at encoding can enhance infant learning and memory performance within an age, suggesting that brain maturation alone cannot fully account for all developmental changes in early memory abilities. The present study investigated whether changes in the focus of attention during learning might contribute to improving memory abilities during infancy. Infants aged 6, 9, and 12 months, and an adult comparison group, watched a video of a puppet imitation demonstration while visual behavior was recorded on an eye tracker. Overall, infants spent less time attending to the video than adults, and distributed their gaze more equally across the demonstrator and puppet stimulus. In contrast, adults directed their gaze primarily to the puppet. When infants were tested for their behavioral recall of the target actions, "imitators" were shown to have increased attention to the person and decreased attention to the background compared to "non-imitators." These results suggest that attention during learning is related to memory outcome and that changes in attention may be one mechanism by which manipulations to the learning event may enhance infant recall memory.

Infants segment continuous events using transitional probabilities

Throughout their 1st year, infants adeptly detect statistical structure in their environment. However, little is known about whether statistical learning is a primary mechanism for event segmentation. This study directly tests whether statistical learning alone is sufficient to segment continuous events. Twenty-eight 7- to 9-month-old infants viewed a sequence of continuous actions performed by a novel agent in which there were no transitional movements that could have constrained the possible upcoming actions. At test, infants distinguished statistically intact units from less predictable ones. The ability to segment events using statistical structure may help infants discover other cues to event boundaries, such as intentions, and carve up the world of continuous motion in meaningful ways.