Gesture as a support for word learning: the case of under

Task effects in children's word recall: Expanding the reverse production effect

Words said aloud are typically recalled more than words studied under other techniques. In certain circumstances, production does not lead to this memory advantage. We investigated the nature of this effect by varying the task during learning. Children aged five to six years were trained on novel words which required no action (Heard) compared to Verbal-Speech (production), Non-Verbal-Speech (stick out tongue), and Non-Verbal-Non-Speech (touch nose). Eye-tracking showed successful learning of novel words in all training conditions, but no differences between conditions. Both non-verbal tasks disrupted recall, demonstrating that encoding can be disrupted when children perform different types of concurrent actions.

The roles of motion, gesture, and embodied action in the processing of mathematical concepts

This article discusses perspective and frame of reference in the metaphorical description of mathematical concepts in terms of motions, gestures, and embodied actions. When a mathematical concept is described metaphorically in terms of gestures, embodied actions, or fictive motions, the motor system comes into play to ground and understand that concept. Every motion, gesture, or embodied action involves a perspective and a frame of reference. The flexibility in taking perspective and frame of reference allows people to embody a mathematical concept or idea in various ways. Based on the findings of past studies, it is suggested that the graphical representation of a mathematical concept may activate those areas of the motor system that are involved in the production of that graphical representation. This is supported by studies showing that when observers look at a painting or handwritten letters, they simulate the painter's or writer's hand movements during painting or writing. Likewise, the motor system can contribute to the grounding of abstract mathematical concepts, such as functions, numbers, and arithmetic operations.

Prior experience with unlabeled actions promotes 3-year-old children's verb learning

[Correction Notice: An Erratum for this article was reported online in Journal of Experimental Psychology: General on Jan 6 2022 (see record 2022-20753-001). In the original article, acknowledgment of and formatting for Economic and Social Research Council funding was omitted. The author note and copyright line now reflect the standard acknowledgment of and formatting for the funding received for this article. All versions of this article have been corrected.] This study investigated what type of prior experience with unlabeled actions promotes 3-year-old children's verb learning. We designed a novel verb learning task in which we manipulated prior experience with unlabeled actions and the gesture type children saw with this prior experience. Experiment 1 showed that children (N = 96) successfully generalized more novel verbs when they had prior experience with unlabeled exemplars of the referent actions ("relevant exemplars"), but only if the referent actions were highlighted with iconic gestures during prior experience. Experiment 2 showed that children (N = 48) successfully generalized more novel verbs when they had prior experience with one relevant exemplar and an iconic gesture than with two relevant exemplars (i.e., the same referent action performed by different actors) shown simultaneously. However, children also successfully generalized verbs above chance in the two-relevant-exemplars condition (without the help of iconic gesture). Overall, these findings suggest that prior experience with unlabeled actions is an important first step in children's verb learning process, provided that children get a cue for focusing on the relevant information (i.e., actions) during prior experience so that they can create stable memory representations of the actions. Such stable action memory representations promote verb learning because they make the actions stand out when children later encounter labeled exemplars of the same actions. Adults can provide top-down cues (e.g., iconic gestures) and bottom-up cues (e.g., simultaneous exemplars) to focus children's attention on actions; however, iconic gesture is more beneficial for successful verb learning than simultaneous exemplars. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Do Shy Preschoolers Interact Differently When Learning Language With a Social Robot? An Analysis of Interactional Behavior and Word Learning

Temperamental traits can decisively influence how children enter into social interaction with their environment. Yet, in the field of child–robot interaction, little is known about how individual differences such as shyness impact on how children interact with social robots in educational settings. The present study systematically assessed the temperament of 28 preschool children aged 4–5 years in order to investigate the role of shyness within a dyadic child–robot interaction. Over the course of four consecutive sessions, we observed how shy compared to nonshy children interacted with a social robot during a word-learning educational setting and how shyness influenced children’s learning outcomes. Overall, results suggested that shy children not only interacted differently with a robot compared to nonshy children, but also changed their behavior over the course of the sessions. Critically, shy children interacted less expressively with the robot in general. With regard to children’s language learning outcomes, shy children scored lower on an initial posttest, but were able to close this gap on a later test, resulting in all children retrieving the learned words on a similar level. When intertest learning gain was considered, regression analyses even confirmed a positive predictive role of shyness on language learning gains. Findings are discussed with regard to the role of shyness in educational settings with social robots and the implications for future interaction design.

Progressive Reduction of Iconic Gestures Contributes to School-Aged Children's Increased Word Production

The economic principle of communication, according to which successful communication can be reached by least effort, has been studied for verbal communication. With respect to nonverbal behavior, it implies that forms of iconic gestures change over the course of communication and become reduced in the sense of less pronounced. These changes and their effects on learning are currently unexplored in relevant literature. Addressing this research gap, we conducted a word learning study to test the effects of changing gestures on children's slow mapping. We applied a within-subject design and tested 51 children, aged 6.7 years (SD = 0.4), who learned unknown words from a story. The storyteller acted on the basis of two conditions: In one condition, in which half of the target words were presented, the story presentation was enhanced with progressively reduced iconic gestures (PRG); in the other condition, half of the target words were accompanied by fully executed iconic gestures (FEG). To ensure a reliable gesture presentation, children were exposed to a recorded person telling a story in both conditions. We tested the slow mapping effects on children's productive and receptive word knowledge three minutes as well as two to three days after being presented the story. The results suggest that children's production of the target words, but not their understanding thereof, was enhanced by PRG.

Caregivers use gesture contingently to support word learning

Children learn words in environments where there is considerable variability, both in terms of the number of possible referents for novel words, and the availability of cues to support word-referent mappings. How caregivers adapt their gestural cues to referential uncertainty has not yet been explored. We tested a computational model of cross-situational word learning that examined the value of a variable gesture cue during training across conditions of varying referential uncertainty. We found that gesture had a greater benefit for referential uncertainty, but unexpectedly also found that learning was best when there was variability in both the environment (number of referents) and gestural cue use. We demonstrated that these results are reflected behaviourally in an experimental word-learning study involving children aged 18-24-month-olds and their caregivers. Under similar conditions to the computational model, caregivers not only used gesture more when there were more potential referents for novel words, but children also learned best when there was some referential ambiguity for words. Thus, caregivers are sensitive to referential uncertainty in the environment and adapt their gestures accordingly, and children are able to respond to environmental variability to learn more robustly. These results imply that training under variable circumstances may actually benefit learning, rather than hinder it.

Non-verbal Enrichment in Vocabulary Learning With a Virtual Pedagogical Agent

Non-verbal enrichment in the form of pictures or gesture can support word learning in first and foreign languages. The present study seeks to compare the effects of viewing pictures vs. imitating iconic gestures on learning second language (L2) vocabulary. In our study participants learned L2 words (nouns, verbs, and adjectives) together with a virtual, pedagogical agent. The to-be-learned items were either (i) enriched with pictures, or (ii) with gestures that had to be imitated, or (iii) without any non-verbal enrichment as control. Results showed that gesture imitation was particularly supportive for learning nouns, whereas pictures showed to be most beneficial for memorizing verbs. These findings, suggesting that the type of vocabulary learning strategy has to match with the type of linguistic material to be learned, have important educational implications for L2 classrooms and technology-enhanced tutoring systems.

Seeing Iconic Gesture Promotes First- and Second-Order Verb Generalization in Preschoolers

This study investigated whether seeing iconic gestures depicting verb referents promotes two types of generalization. We taught 3- to 4-year-olds novel locomotion verbs. Children who saw iconic manner gestures during training generalized more verbs to novel events (first-order generalization) than children who saw interactive gestures (Experiment 1, N = 48; Experiment 2, N = 48) and path-tracing gestures (Experiment 3, N = 48). Furthermore, immediately (Experiments 1 and 3) and after 1 week (Experiment 2), the iconic manner gesture group outperformed the control groups in subsequent generalization trials with different novel verbs (second-order generalization), although all groups saw interactive gestures. Thus, seeing iconic gestures that depict verb referents helps children (a) generalize individual verb meanings to novel events and (b) learn more verbs from the same subcategory.

Integrated Communication System: Gesture and Language Acquisition in Typically Developing Children and Children With LD and DLD

Gesture and language development are strongly connected to each other. Two types of gestures in particular are analyzed regarding their role for language acquisition: pointing and iconic gestures. With the present longitudinal study, the predictive values of index-finger pointing at 12 months and the comprehension of iconic gestures at 3;0 years for later language skills in typically developing (TD) children and in children with a language delay (LD) or developmental language disorder (DLD) are examined. Forty-two monolingual German children and their primary caregivers participated in the study and were followed longitudinally from 1;0 to 6;0 years. Within a total of 14 observation sessions, the gestural and language abilities of the children were measured using standardized as well as ad hoc tests, parent questionnaires and semi-natural interactions between the child and their caregivers. At the age of 2;0 years, 10 of the 42 children were identified as having a LD. The ability to point with the extended index finger at 1;0 year is predictive for language skills at 5;0 and 6;0 years. This predictive effect is mediated by the language skills of the children at 3;0 years. The comprehension of iconic gestures at 3;0 years correlates with index-finger pointing at 1;0 year and also with earlier and later language skills. It mediates the predictive value of index-finger pointing at 1;0 year for grammar skills at 5;0 and 6;0 years. Children with LD develop the ability to understand the iconicity in gestures later than TD children and score lower in language tests until the age of 6;0 years. The language differences between these two groups of children persist partially until the age of 5;0 years even when the two children with manifested DLD within the group of children with LD are excluded from analyses. Beyond that age, no differences in the language skills between children with and without a history of LD are found when children with a manifest DLD are excluded. The findings support the assumption of an integrated speech–gesture communication system, which functions similarly in TD children and children with LD or DLD, but with a time delay.

The effects of observing different gestures during storytelling on the recall of path and event information in 5-year-olds and adults

This study examined (a) how observing different types of gestures while listening to a story affected the recall of path and event information in 5-year-old children (n = 71) and adults (n = 55) and (b) whether the effects of gesture type on children's recall of information were related to individual differences such as working memory, language abilities, spontaneous gesture use, and gesture production during the recall task. Participants were asked four questions to measure their spontaneous gesture frequency. They then listened to a story that included different path and event information. Depending on the assigned condition, participants listened to the story with the narrator producing iconic gestures (gestures having semantic meaning), beat gestures (rhythmic hand movements), or no gesture. We then asked participants to relate what happened in the story and administered a recognition task about the story. Children were given standardized tests to assess their language and working memory skills. Children and adults best recalled the story after observing iconic gestures as compared with children and adults presented with beat gestures or no gestures. Children who were exposed to iconic gestures during encoding better recalled event information than children in the other conditions. Children's language abilities, but not working memory, were related to their recall performance. More important, children with better expressive language abilities benefitted more from seeing iconic gestures. These results suggest that observing iconic gestures at encoding facilitates recall and that children's language skills could play a role in encoding and using specific information provided by gestures.

Sound Symbolism Facilitates Long-Term Retention of the Semantic Representation of Novel Verbs in Three-Year-Olds

Previous research has shown that sound symbolism facilitates action label learning when the test trial used to assess learning immediately followed the training trial in which the (novel) verb was taught. The current study investigated whether sound symbolism benefits verb learning in the long term. Forty-nine children were taught either sound-symbolically matching or mismatching pairs made up of a novel verb and an action video. The following day, the children were asked whether a verb can be used for a scene shown in a video. They were tested with four videos for each word they had been taught. The four videos differed as to whether they contained the same or different actions and actors as in the training video: (1) same-action, same-actor; (2) same-action, different-actor; (3) different-action, same-actor; and (4) different-action, different-actor. The results showed that sound symbolism significantly improved the childrens’ ability to encode the semantic representation of the novel verb and correctly generalise it to a new event the following day. A control experiment ruled out the possibility that children were generalising to the “same-action, different-actor” video because they did not recognize the actor change due to the memory decay. Nineteen children were presented with the stimulus videos that had also been shown to children in the sound symbolic match condition in Experiment 1, but this time the videos were not labeled. In the test session the following day, the experimenter tested the children’s recognition memory for the videos. The results indicated that the children could detect the actor change from the original training video a day later. The results of the main experiment and the control experiment support the idea that a motivated (iconic) link between form and meaning facilitates the symbolic development in children. The current study, along with recent related studies, provided further evidence for an iconic advantage in symbol development in the domain of verb learning. A motivated form-meaning relationship can help children learn new words and store them long term in the mental lexicon.

Prosody in the Auditory and Visual Domains: A Developmental Perspective

The development of body movements such as hand or head gestures, or facial expressions, seems to go hand-in-hand with the development of speech abilities. We know that very young infants rely on the movements of their caregivers' mouth to segment the speech stream, that infants' canonical babbling is temporally related to rhythmic hand movements, that narrative abilities emerge at a similar time in speech and gestures, and that children make use of both modalities to access complex pragmatic intentions. Prosody has emerged as a key linguistic component in this speech-gesture relationship, yet its exact role in the development of multimodal communication is still not well understood. For example, it is not clear what the relative weights of speech prosody and body gestures are in language acquisition, or whether both modalities develop at the same time or whether one modality needs to be in place for the other to emerge. The present paper reviews existing literature on the interactions between speech prosody and body movements from a developmental perspective in order to shed some light on these issues.

With Some Help From Others' Hands: Iconic Gesture Helps Semantic Learning in Children With Specific Language Impairment

PURPOSE

Semantic learning under 2 co-speech gesture conditions was investigated in children with specific language impairment (SLI) and typically developing (TD) children. Learning was analyzed between conditions.

METHOD

Twenty children with SLI (aged 4 years), 20 TD children matched for age, and 20 TD children matched for language scores were taught rare nouns and verbs. Children heard the target words while seeing either iconic gestures illustrating a property of the referent or a control gesture focusing children's attention on the word. Following training, children were asked to define the words' meaning. Responses were coded for semantic information provided on each word.

RESULTS

Performance of the SLI and age-matched groups proved superior to that of the language-matched group. Overall, children defined more words taught with iconic gestures than words taught with attention-getting gestures. However, only children with SLI, but not TD children, provided more semantic information on each word taught with iconic gestures. Performance did not differ in terms of word class.

CONCLUSIONS

Results suggest that iconic co-speech gestures help both children with and without SLI learn new words but, in particular, assist children with SLI understand and reflect the words' meaning.

Observing iconic gestures enhances word learning in typically developing children and children with specific language impairment

Research has shown that observing iconic gestures helps typically developing children (TD) and children with specific language impairment (SLI) learn new words. So far, studies mostly compared word learning with and without gestures. The present study investigated word learning under two gesture conditions in children with and without language impairment. Twenty children with SLI (age four), twenty age-matched TD children, and twenty language-matched TD children were taught words that were presented with either iconic or non-iconic gestures. Results showed that children of all groups benefited more successfully from observing iconic gestures for word learning. The iconic gesture advantage was similar across groups. Thus, observing iconic gestures prompts richer encoding and makes word learning more efficient in TD and language impaired children.

From hands to minds: Gestures promote understanding

Gestures serve many roles in communication, learning and understanding both for those who view them and those who create them. Gestures are especially effective when they bear resemblance to the thought they represent, an advantage they have over words. Here, we examine the role of conceptually congruent gestures in deepening understanding of dynamic systems. Understanding the structure of dynamic systems is relatively easy, but understanding the actions of dynamic systems can be challenging. We found that seeing gestures representing actions enhanced understanding of the dynamics of a complex system as revealed in invented language, gestures and visual explanations. Gestures can map many meanings more directly than language, representing many concepts congruently. Designing and using gestures congruent with meaning can augment comprehension and learning.

Can 28-Month-Old Children Learn Spatial Prepositions Robustly from Pictures? Yes, When Narrative Input Is Provided

The learning of spatial prepositions is assumed to be based on experience in space. In a slow mapping study, we investigated whether 31 German 28-month-old children could robustly learn the German spatial prepositions hinter [behind] and neben [next to] from pictures, and whether a narrative input can compensate for a lack of immediate experience in space. One group of children received pictures with a narrative input as a training to understand spatial prepositions. In two further groups, we controlled (a) for the narrative input by providing unconnected speech during the training and (b) for the learning material by training the children on toys rather than pictures. We assessed children's understanding of spatial prepositions at three different time points: pretest, immediate test, and delayed posttest. Results showed improved word retention in children from the narrative but not the control group receiving unconnected speech. Neither of the trained groups succeeded in generalization to novel referents. Finally, all groups were instructed to deal with untrained material in the test to investigate the robustness of learning across tasks. None of the groups succeeded in this task transfer.

Gesture and speech during shared book reading with preschoolers with specific language impairment

This study examined (a) the relationship between gesture and speech produced by children with specific language impairment (SLI) and typically developing (TD) children, and their mothers, during shared book-reading, and (b) the potential effectiveness of gestures accompanying maternal speech on the conversational responsiveness of children. Fifteen preschoolers with expressive SLI were compared with fifteen age-matched and fifteen language-matched TD children. Child and maternal utterances were coded for modality, gesture type, gesture-speech informational relationship, and communicative function. Relative to TD peers, children with SLI used more bimodal utterances and gestures adding unique information to co-occurring speech. Some differences were mirrored in maternal communication. Sequential analysis revealed that only in the SLI group maternal reading accompanied by gestures was significantly followed by child's initiatives, and when maternal non-informative repairs were accompanied by gestures, they were more likely to elicit adequate answers from children. These findings support the 'gesture advantage' hypothesis in children with SLI, and have implications for educational and clinical practice.

Learning from gesture: How our hands change our minds

When people talk, they gesture, and those gestures often reveal information that cannot be found in speech. Learners are no exception. A learner's gestures can index moments of conceptual instability, and teachers can make use of those gestures to gain access into a student's thinking. Learners can also discover novel ideas from the gestures they produce during a lesson, or from the gestures they see their teachers produce. Gesture thus has the power not only to reflect a learner's understanding of a problem, but also to change that understanding. This review explores how gesture supports learning across development, and ends by offering suggestions for ways in which gesture can be recruited in educational settings.

The Development of the Ability to Semantically Integrate Information in Speech and Iconic Gesture in Comprehension

We examined whether children's ability to integrate speech and gesture follows the pattern of a broader developmental shift between 3- and 5-year-old children (Ramscar & Gitcho, 2007) regarding the ability to process two pieces of information simultaneously. In Experiment 1, 3-year-olds, 5-year-olds, and adults were presented with either an iconic gesture or a spoken sentence or a combination of the two on a computer screen, and they were instructed to select a photograph that best matched the message. The 3-year-olds did not integrate information in speech and gesture, but 5-year-olds and adults did. In Experiment 2, 3-year-old children were presented with the same speech and gesture as in Experiment 1 that were produced live by an experimenter. When presented live, 3-year-olds could integrate speech and gesture. We concluded that development of the integration ability is a part of the broader developmental shift; however, live-presentation facilitates the nascent integration ability in 3-year-olds.

Co-Speech Gesture Input as a Support for Language Learning in Children With and Without Early Language Delay

The current paper provides empirical support for adults using co-speech gesturing with children with and without early language delay. The discussion starts broad by showing that co-speech gestures are already in the child's language environment. We then show that encouraging co-speech gesturing by adults promotes language development and use in children. The discussion is then narrowed to the review of the finer aspects of word learning which sets the stage for how iconic gestures can be utilized in language therapy. Finally, we show that pairing iconic gestures with word models promotes word learning.

Learning, forgetting, and relearning: skill learning in children with language impairment

PURPOSE

The current study tested whether the difficulties of children with specific language impairment (SLI) in skill acquisition are related to learning processes that occur while practicing a new skill or to the passage of time between practice and later performance.

METHOD

The acquisition and retention of a new complex grapho-motor symbol were studied in 5-year-old children with SLI and peers matched for age and nonverbal IQ. The children practiced the production of the symbol for 4 consecutive days. Retention testing took place 10 days later.

RESULTS

Children with SLI began each practice day slower than their peers but attained similar levels of performance by its end. Although they increased their performance speed within sessions more than their peers, they did not retain their learning as well between sessions. The loss in speed was largest in the 10-day retention interval. They were also less accurate, but accuracy differences decreased over time. Between-session group differences in speed could not fully be accounted for based on fine motor skills.

CONCLUSIONS

In spite of effective within-session learning, children with SLI did not retain the new skill well. The deficit may be attributed to task forgetting in the presence of delayed consolidation processes.

Role of maternal gesture use in speech use by children with fragile X syndrome

PURPOSE

The purpose of this study was to investigate how maternal gesture relates to speech production by children with fragile X syndrome (FXS).

METHOD

Participants were 27 young children with FXS (23 boys, 4 girls) and their mothers. Videotaped home observations were conducted between the ages of 25 and 37 months (toddler period) and again between the ages of 60 and 71 months (child period). The videos were later coded for types of maternal utterances and maternal gestures that preceded child speech productions. Children were also assessed with the Mullen Scales of Early Learning at both ages.

RESULTS

Maternal gesture use in the toddler period was positively related to expressive language scores at both age periods and was related to receptive language scores in the child period. Maternal proximal pointing, in comparison to other gestures, evoked more speech responses from children during the mother-child interactions, particularly when combined with wh-questions.

CONCLUSION

This study adds to the growing body of research on the importance of contextual variables, such as maternal gestures, in child language development. Parental gesture use may be an easily added ingredient to parent-focused early language intervention programs.

Children use gesture to interpret novel verb meanings

Children often find it difficult to map verbs to specific referents within complex scenes, often believing that additional features are part of the referents. This study investigated whether 3-year-olds could use iconic gestures to map novel verbs to specific referents. One hundred and twenty children were taught verbs that could be interpreted as change-of-state or manner verbs while presented with manner, end-state, or no iconic gestures. Children were then presented with a choice that forced them to generalize either on the basis of manner or end state. Results showed that children who saw manner gestures showed a stronger manner bias compared to the other groups. Thus, the specific feature of an event encoded in gestures guides children's interpretations of novel words.

A story about a word: does narrative presentation promote learning of a spatial preposition in German two-year-olds?

We trained forty German-speaking children aged 1;8-2;0 in their comprehension of UNTER [UNDER]. The target word was presented within semantically organized input in the form of a 'narrative' to the experimental group and within 'unconnected speech' to the control group. We tested children's learning by asking them to perform an UNDER-relation before, immediately after, and again one day after the training using familiarized and unfamiliarized materials. Compared to controls, the experimental group learned better and retained more. Children with advanced expressive lexicons in particular were aided in generalizing to unfamiliarized materials by the narrative presentation. This study extends our understanding of how narrations scaffold young children's enrichment of nascent word knowledge.

Context and repetition in word learning

Young children learn words from a variety of situations, including shared storybook reading. A recent study by Horst et al. (2011a) demonstrates that children learned more new words during shared storybook reading if they were read the same stories repeatedly than if they were read different stories that had the same number of target words. The current paper reviews this study and further examines the effect of contextual repetition on children's word learning in both shared storybook reading and other situations, including fast mapping by mutual exclusivity. The studies reviewed here suggest that the same cognitive mechanisms support word learning in a variety of situations. Both practical considerations for experimental design and directions for future research are discussed.

The First Slow Step: Differential Effects of Object and Word-Form Familiarization on Retention of Fast-Mapped Words

Recent research demonstrated that although twenty-four month-old infants do well on the initial pairing of a novel word and novel object in fast-mapping tasks, they are unable to retain the mapping after a five-minute delay. The current study examines the role of familiarity with the objects and words on infants' ability to bridge between the initial fast mapping of a name and object, and later retention in the service of slow mapping. Twenty-four-month-old infants were familiarized with either novel objects or novel names prior to the referent selection portion of a fast-mapping task. When familiarized with the novel objects, infants retained the novel mapping after a delay, but not when familiarized with the novel words. This suggests familiarity with the object versus the word form leads to differential encoding of the name-object link. We discuss the implications of this finding for subsequent slow mapping.

Why Word Learning is not Fast

Upon fast mapping, children rarely retain new words even over intervals as short as 5 min. In this study, we asked whether the memory process of encoding or consolidation is the bottleneck to retention. Forty-nine children, mean age 33 months, were exposed to eight 2- or-3-syllable nonce neighbors of words in their existing lexicons. Didactic training consisted of six exposures to each word in the context of its referent, an unfamiliar toy. Productions were elicited four times: immediately following the examiner's model, and at 1-min-, 5-min-, and multiday retention intervals. At the final two intervals, the examiner said the first syllable and provided a beat gesture highlighting target word length in syllables as a cue following any erred production. The children were highly accurate at immediate posttest. Accuracy fell sharply over the 1-min retention interval and again after an additional 5 min. Performance then stabilized such that the 5-min and multiday posttests yielded comparable performance. Given this time course, we conclude that it was not the post-encoding process of consolidation but the process of encoding itself that presented the primary bottleneck to retention. Patterns of errors and responses to cueing upon error suggested that word forms were particularly vulnerable to partial decay during the time course of encoding.

Fast Mapping Across Time: Memory Processes Support Children's Retention of Learned Words

Children's remarkable ability to map linguistic labels to referents in the world is commonly called fast mapping. The current study examined children's (N = 216) and adults' (N = 54) retention of fast-mapped words over time (immediately, after a 1-week delay, and after a 1-month delay). The fast mapping literature often characterizes children's retention of words as consistently high across timescales. However, the current study demonstrates that learners forget word mappings at a rapid rate. Moreover, these patterns of forgetting parallel forgetting functions of domain-general memory processes. Memory processes are critical to children's word learning and the role of one such process, forgetting, is discussed in detail - forgetting supports extended mapping by promoting the memory and generalization of words and categories.

Gesture in the developing brain

Speakers convey meaning not only through words, but also through gestures. Although children are exposed to co-speech gestures from birth, we do not know how the developing brain comes to connect meaning conveyed in gesture with speech. We used functional magnetic resonance imaging (fMRI) to address this question and scanned 8- to 11-year-old children and adults listening to stories accompanied by hand movements, either meaningful co-speech gestures or meaningless self-adaptors. When listening to stories accompanied by both types of hand movement, both children and adults recruited inferior frontal, inferior parietal, and posterior temporal brain regions known to be involved in processing language not accompanied by hand movements. There were, however, age-related differences in activity in posterior superior temporal sulcus (STSp), inferior frontal gyrus, pars triangularis (IFGTr), and posterior middle temporal gyrus (MTGp) regions previously implicated in processing gesture. Both children and adults showed sensitivity to the meaning of hand movements in IFGTr and MTGp, but in different ways. Finally, we found that hand movement meaning modulates interactions between STSp and other posterior temporal and inferior parietal regions for adults, but not for children. These results shed light on the developing neural substrate for understanding meaning contributed by co-speech gesture.