The development of the object sequencing imitation task to measure working memory in preschoolers.

We developed a new object sequencing imitation (OSI) task for preschoolers. We parameterized the task to test the effects of working memory load in 56 3- to 5-year-old children in a museum. We tested individual groups of 3-, 4-, and 5-year-olds on both "low" (2- to 4-step) and "high" (3- to 5-step) memory load sequences on two variants of the task. The experimenter demonstrated each sequence three times, and children were given 3 trials to imitate the sequence, receiving feedback from the experimenter following each trial. Children were tested on an object that was functionally the same but perceptually different. All preschoolers performed significantly above baseline. We found a significant load effect, showing that performance decreased with increasing steps per sequence. There was no effect of age on performance, showing that leveling of the task across age was successful. Overall, the newly developed OSI task can test age- and load-related changes in working memory in 3- to 5-year-old children. The new OSI task will have utility in longitudinal studies and in studies where multiple trials are needed such as neuroimaging.

Actions speak louder than words: Differences in memory flexibility between monolingual and bilingual 18-month-olds.

Bilingual infants from 6- to 24-months of age are more likely to generalize, flexibly reproducing actions on novel objects significantly more often than age-matched monolingual infants are. In the current study, we examine whether the addition of novel verbal labels enhances memory generalization in a perceptually complex imitation task. We hypothesized that labels would provide an additional retrieval cue and aid memory generalization for bilingual infants. Specifically, we hypothesized that bilinguals might be more likely than monolinguals to map multiple perceptual features onto a novel label and therefore show enhanced generalization. Eighty-seven 18-month-old monolingual and bilingual infants were randomly assigned to one of two experimental conditions or a baseline control condition. In the experimental conditions, either no label or a novel label was added during demonstration and again at the beginning of the test session. After a 24-hr delay, infants were tested with the same stimulus set to test cued recall and with a perceptually different but functionally equivalent stimulus set to test memory generalization. Bilinguals performed significantly above baseline on both cued recall and memory generalization in both experimental conditions, whereas monolinguals performed significantly above baseline only on cued recall in both experimental conditions. These findings show a difference between monolinguals and bilinguals in memory generalization and suggest that generalization differences between groups may arise from visual perceptual processing rather than linguistic processing. A video abstract of this article can be viewed at https://youtu.be/yXB4pM3fF2k.

How self-generated labelling shapes transfer of learning during early childhood: The role of individual differences.

Multiple factors influence imitation during toddlerhood, including task complexity, social contingency, and individual differences. We conducted a secondary data analysis of individual differences in self-generated labelling using data collected from a complex puzzle imitation task with 355 2- to 3-year-olds. This analysis indicated that toddlers' ability to label the completed puzzle (fish or boat) was associated with better imitation performance. Labelling occurs during social interactions; therefore, our second analysis tested how labelling differed as a function of the level of social scaffolding in each condition. This analysis revealed that self-generated labelling was lower when the social demonstrator was removed and the task was presented on a touchscreen. This study is one of the first to examine self-generated labelling during a complex imitation task in toddlers and increases our understanding of the complexity of memory processing needed for imitation learning. Statement of contribution What is already known on this subject? Toddlers exhibit a transfer of learning deficit from 2D media, including books, TV, and tablets. Self-generated labelling enhances children's learning, through attentional and cognitive mechanisms. Children are sensitive to reduced social cues in screen media contributing to the transfer deficit. What does this study add? Self-generated labelling is associated with better goal imitation performance. Self-generated labelling occurs more frequently under social conditions.