Children learn words easier when they are interested in the category to which the word belongs

The overall pattern of vocabulary development is relatively similar across children learning different languages. However, there are considerable differences in the words known to individual children. Historically, this variability has been explained in terms of differences in the input. Here, we examine the alternate possibility that children's individual interest in specific natural categories shapes the words they are likely to learn – a child who is more interested in animals will learn a new animal name easier relative to a new vehicle name. Two‐year‐old German‐learning children (N = 39) were exposed to four novel word–object associations for objects from four different categories. Prior to the word learning task, we measured their interest in the categories that the objects belonged to. Our measure was pupillary change following exposure to familiar objects from these four categories, with increased pupillary change interpreted as increased interest in that category. Children showed more robust learning of word–object associations from categories they were more interested in relative to categories they were less interested in. We further found that interest in the novel objects themselves influenced learning, with distinct influences of both category interest and object interest on learning. These results suggest that children's interest in different natural categories shapes their word learning. This provides evidence for the strikingly intuitive possibility that a child who is more interested in animals will learn novel animal names easier than a child who is more interested in vehicles.     

The role of competition in word learning via referent selection

Previous research suggests that competition among the objects present during referent selection influences young children’s ability to learn words in fast mapping tasks. The present study systematically explored this issue with 30‐month‐old children. Children first received referent selection trials with a target object and either two, three or four competitor objects. Then, after a short delay, children were tested on their ability to retain the newly fast‐mapped names. Overall, the number of competitors did not affect children’s ability to form the initial name–object mappings. However, only children who encountered few competitors during referent selection demonstrated significant levels of retention. Results and implications are discussed in terms of the role of competition in studies of children’s fast mapping. The relationship between referent selection and full word learning is also discussed.     

A bottom-up view of toddler word learning

A head camera was used to examine the visual correlates of object name learning by toddlers as they played with novel objects and as the parent spontaneously named those objects. The toddlers’ learning of the object names was tested after play, and the visual properties of the head camera images during naming events associated with learned and unlearned object names were analyzed. Naming events associated with learning had a clear visual signature, one in which the visual information itself was clean and visual competition among objects was minimized. Moreover, for learned object names, the visual advantage of the named target over competitors was sustained, both before and after the heard name. The findings are discussed in terms of the visual and cognitive processes that may depend on clean sensory input for learning and also on the sensory–motor, cognitive, and social processes that may create these optimal visual moments for learning.     

Object name learning provides on-the-job training for attention

By the age of 3, children easily learn to name new objects, extending new names for unfamiliar objects by similarity in shape. Two experiments tested the proposal that experience in learning object names tunes children's attention to the properties relevant for naming—in the present case, to the property of shape—and thus facilitates the learning of more object names. In Experiment 1, a 9-week longitudinal study, 17-month-old children who repeatedly played with and heard names for members of unfamiliar object categories well organized by shape formed the generalization that only objects with similar shapes have the same name. Trained children also showed a dramatic increase in acquisition of new object names outside of the laboratory during the course of the study. Experiment 2 replicated these findings and showed that they depended on children's learning both a coherent category structure and object names. Thus, children who learn specific names for specific things in categories with a common organizing property—in this case, shape—also learn to attend to just the right property—in this case, shape—for learning more object names.     

Learning names for materials: Factors constraining and limiting hypotheses about word meaning

Children's ability to learn new words quickly (Carey, 1978; Dickinson, 1984b; Heibeck & Markman, in press) indicates that they have strategies for constraining hypotheses about word meaning. The initial hypotheses children entertain about the meaning of words that name materials were examined in two studies. The first study examined the effects of linguistic constraint supplied by count/mass syntactic information and of conceptual constraints—Object Bias for Solids (i.e., words applied to solids name objects, not materials; Soja, Carey, & Spelke, 1985), and Substance Bias for Nonsolids (i.e., words applied to nonsolids name materials). A second study investigated the effects of providing more explicit information about word meaning by including the phrase “made of” when words were presented. In both studies, 16 children, aged 3, 4, and 5, were introduced to an object or material and told a name for it in phrases that varied the information provided. They then were shown two items and asked to indicate which was an example of the presentation stimulus. Mass syntax was somewhat effective in helping children map words to material concepts, but conceptual constraints were more important. Children of all ages were poor at learning names for materials when the word referred to unfamiliar objects made of unfamiliar materials, but the phrase “made of” helped reduce the effect of the Object Bias for Solids among 5-year-olds. Age-related developments suggest that acquisition of material names also is affected by improving access to material concepts.     

How children name objects with shoes

Many studies report a shape bias in children's learning of object names. However, one previous study suggests that the shape bias is not the only perceptually based bias displayed by children learning count nouns. Specifically, children attended to texture as well as shape when extending a novel name to novel objects with eyes. Two experiments attempt to extend this finding, asking whether children will also attend to texture in the presence of another cue to animacy—shoes. In Experiment 1, 80 2- and 3-year-olds participated in either a Name generalization or Similarity judgment task. The novel objects were identical except that for half of the children the objects had shoes. In the Similarity condition, children made their judgments by overall similarity. In the Name condition, 2-year-olds extended the novel name by shape across objects both with and without shoes. In contrast, 3-year-olds generalized the novel name by shape when the objects had no shoes but by texture when the objects had shoes. Experiment 2 challenged this finding, using a forced choice procedure and objects that differed from the named exemplar more markedly in shape. Twenty 3-year-olds participated in a Name generalization task, half for objects with shoes, half for objects without shoes. Again, children attended reliably more to texture when the objects had shoes than when they had no shoes. The results are discussed in terms of the development of different perceptually based biases and the relation of such biases to a taxonomic bias in early word learning.     

Late talkers show no shape bias in a novel name extension task

By 2½ years of age, children typically show a shape bias in object naming – that is, they extend object names mostly to new instances with the same shape. The acquisition of a shape bias is related to a marked increase in the rate of object name learning. This study asks whether, conversely, children who do not readily acquire new object names lack a shape bias. Twelve 2- to 3-year-old ‘late talkers’– children whose total vocabularies rank below the 30th percentile for their age – were compared with age-matched children with larger vocabularies in a novel object name extension task. The controls extended novel names across novel objects with the same shape. The late talkers showed no group perceptual bias, but many individuals extended novel names across objects with the same surface texture. The implications of the results both for the role of attentional biases in object name learning and for the etiology of some late talking are discussed.      

Intentionality and word learning

Humans intuitively think about the actions of others in terms of mental states eliefs, desires, emotions and intentions. This 'theory of mind' plays a central role in how children learn the meanings of certain words. First, it underlies how they determine the reference of a novel word. When children hear a new object name (e.g. 'Look at the fendle'), they do not use spatio-temporal contiguity to determine what the word describes; instead they focus on cues to the referential intention of the speaker, such as direction of gaze. Second, an understanding of purpose and design is sometimes necessary to enable the child to understand the entities and actions that nouns and verbs refer to. This is particularly relevant for nouns that refer to collections of objects such as 'family' and 'game', and for verbs that refer to actions defined in terms of an actor's goals, such as 'give' and 'make'. Finally, intentional considerations partially underlie the generalization of names for artifact categories, such as 'chair' and 'clock', which can refer to entities of highly dissimilar appearance.     

The role of novelty in early word learning

What mechanism implements the mutual exclusivity bias to map novel labels to objects without names? Prominent theoretical accounts of mutual exclusivity (e.g., Markman, 1989, 1990 ) propose that infants are guided by their knowledge of object names. However, the mutual exclusivity constraint could be implemented via monitoring of object novelty (see Merriman, Marazita, & Jarvis, 1995 ). We sought to discriminate between these contrasting explanations across two preferential looking experiments with 22‐month‐olds. In Experiment 1, infants viewed three objects: one name‐known, two name‐unknown. Of the two name‐unknown objects, one was novel, and the other had been previously familiarized. The infants responded to hearing a novel label by increasing attention only to the novel, name‐unknown object. In a second experiment in which the name‐known object was absent, a novel label increased infants’ attention to a novel object beyond baseline preference for novelty. The experiments provide clear evidence for a novelty‐based mechanism. However, differences in the time course of disambiguation across experiments suggest that novelty processing may be influenced by contextual factors.     

Embodied attention and word learning by toddlers

Many theories of early word learning begin with the uncertainty inherent to learning a word from its co-occurrence with a visual scene. However, the relevant visual scene for infant word learning is neither from the adult theorist's view nor the mature partner's view, but is rather from the learner's personal view. Here we show that when 18-month old infants interacted with objects in play with their parents, they created moments in which a single object was visually dominant. If parents named the object during these moments of bottom-up selectivity, later forced-choice tests showed that infants learned the name, but did not when naming occurred during a less visually selective moment. The momentary visual input for parents and toddlers was captured via head cameras placed low on each participant's forehead as parents played with and named objects for their infant. Frame-by-frame analyses of the head camera images at and around naming moments were conducted to determine the visual properties at input that were associated with learning. The analyses indicated that learning occurred when bottom-up visual information was clean and uncluttered. The sensory-motor behaviors of infants and parents were also analyzed to determine how their actions on the objects may have created these optimal visual moments for learning. The results are discussed with respect to early word learning, embodied attention, and the social role of parents in early word learning.     

Comparison Facilitates Children's Learning of Names for Parts

Learning names for parts of objects can be challenging for children, as it requires overcoming their tendency to name whole objects. We test whether comparing items can facilitate learning names for their parts. Applying the structure-mapping theory of comparison leads to two predictions: (a) young children will find it easier to identify a common part between two very similar items than between two dissimilar items (because the similar pair is easier to align); (b) close alignments potentiate far alignments: children will be better able to extend a novel part name to a dissimilar object after having extended it to a similar object. In three studies, 227 preschool children mapped novel part terms to new animals or objects. Both predictions were confirmed. Children more accurately extended novel part terms to objects that were similar to the standard than to objects that were dissimilar (Experiments 1 and 2), and children more accurately extended novel part names to dissimilar objects after having extended them to similar objects (Experiment 3). We conclude that structure-mapping processes can support part learning.     

What Is the Buzz About Iconicity? How Iconicity in Caregiver Speech Supports Children's Word Learning

One cue that may facilitate children's word learning is iconicity, or the correspondence between a word's form and meaning. Some have even proposed that iconicity in the early lexicon may serve to help children learn how to learn words, supporting the acquisition of even noniconic, or arbitrary, word–referent associations. However, this proposal remains untested. Here, we investigate the iconicity of caregivers’ speech to young children during a naturalistic free-play session with novel stimuli and ask whether the iconicity of caregivers’ speech facilitates children's learning of the noniconic novel names of those stimuli. Thirty-four 1.5-2-year-olds (19 girls; half monolingual English learners and half bilingual English-Spanish learners) participated in a naturalistic free-play task with their caregivers followed by a test of word-referent retention. We found that caregivers’ use of iconicity, particularly in utterances in which they named the novel stimuli, was associated with the likelihood that children learned that novel name. This result held even when controlling for other factors associated with word learning, such as the concreteness and frequency of words in caregiver speech. Together, the results demonstrate that iconicity not only can serve to help children identify the referent of novel words (as in previous research) but can also support their ability to retain even noniconic word-referent mappings.     

Use of the mutual exclusivity assumption by young word learners

A critical question about early word learning is whether word learning constraints such as mutual exclusivity exist and foster early language acquisition. It is well established that children will map a novel label to a novel rather than a familiar object. Evidence for the role of mutual exclusivity in such indirect word learning has been questioned because: (1) it comes mostly from 2 and 3-year-olds and (2) the findings might be accounted for, not by children avoiding second labels, but by the novel object which creates a lexical gap children are motivated to fill. Three studies addressed these concerns by having only a familiar object visible. Fifteen to seventeen and 18-20-month-olds were selected to straddle the vocabulary spurt. In Study 1, babies saw a familiar object and an opaque bucket as a location to search. Study 2 handed babies the familiar object to play with. Study 3 eliminated an obvious location to search. On the whole, babies at both ages resisted second labels for objects and, with some qualifications, tended to search for a better referent for the novel label. Thus mutual exclusivity is in place before the onset of the naming explosion. The findings demonstrate that lexical constraints enable babies to learn words even under non-optimal conditions--when speakers are not clear and referents are not visible. The results are discussed in relation to an alternative social-pragmatic account.     

Pragmatics aid referent disambiguation and word learning in young children and adults

How do children succeed in learning a word? Research has shown robustly that, in ambiguous labeling situations, young children assume novel labels to refer to unfamiliar rather than familiar objects. However, ongoing debates center on the underlying mechanism: Is this behavior based on lexical constraints, guided by pragmatic reasoning, or simply driven by children's attraction to novelty? Additionally, recent research has questioned whether children's disambiguation leads to long-term learning or rather indicates an attentional shift in the moment of the conversation. Thus, we conducted a pre-registered online study with 2- and 3-year-olds and adults. Participants were presented with unknown objects as potential referents for a novel word. Across conditions, we manipulated whether the only difference between both objects was their relative novelty to the participant or whether, in addition, participants were provided with pragmatic information that indicated which object the speaker referred to. We tested participants’ immediate referent selection and their retention after 5 min. Results revealed that when given common ground information both age groups inferred the correct referent with high success and enhanced behavioral certainty. Without this information, object novelty alone did not guide their selection. After 5 min, adults remembered their previous selections above chance in both conditions, while children only showed reliable learning in the pragmatic condition. The pattern of results indicates how pragmatics may aid referent disambiguation and learning in both adults and young children. From early ontogeny on, children's social-cognitive understanding may guide their communicative interactions and support their language acquisition.

Research Highlights

• We tested how 2-3-year-olds and adults resolve referential ambiguity without any lexical cues.
• In the pragmatic context both age groups disambiguated novel word-object-mappings, while object novelty alone did not guide their referent selection.
• In the pragmatic context, children also showed increased certainty in disambiguation and retained new word-object-mappings over time.
• These findings contribute to the ongoing debate on whether children learn words on the basis of domain-specific constraints, lower-level associative mechanisms, or pragmatic inferences.

     

What's in a shape? Children represent shape variability differently than adults when naming objects

Children and adults often generalize a word to objects of the same shape. However, the shape properties on which generalization is based are unknown. We investigated the degree to which two shape dimensions were represented categorically by children and adults when learning names for objects. Multidimensional scaling techniques were used to establish the perceptual similarity of two sets of objects in Experiment 1. In Experiments 2 and 3, children (from 2;8 to 4;5 years of age) and adults participated in two tasks in which they learned a novel name for an exemplar. We then examined how often the novel name was generalized to different objects and to line drawings of the objects. In one task, participants generalized the names from memory; in a second task the exemplar was in front of the participant during generalization. Adults accepted names more often to objects that fell "within" the proposed shape boundaries than to objects that fell "across" the boundaries. Children, however, were just as likely to generalize names to novel objects that fell within as to objects that crossed the boundaries.     

Naming and categorization in young children: IV: listener behavior training and transfer of function

Following pretraining with everyday objects, 14 children aged from 1 to 4 years were trained, for each of three pairs of different arbitrary wooden shapes (Set 1), to select one stimulus in response to the spoken word /zog/, and the other to /vek/. When given a test for the corresponding tacts ("zog" and "vek"), 10 children passed, showing that they had learned common names for the stimuli, and 4 failed. All children were trained to clap to one stimulus of Pair 1 and wave to the other. All those who named showed either transfer of the novel functions to the remaining two pairs of stimuli in Test 1, or novel function comprehension for all three pairs in Test 2, or both. Three of these children next participated in, and passed, category match-to-sample tests. In contrast, all 4 children who had learned only listener behavior failed both the category transfer and category match-to-sample tests. When 3 of them were next trained to name the stimuli, they passed the category transfer and (for the 2 subjects tested) category match-to-sample tests. Three children were next trained on the common listener relations with another set of arbitrary stimuli (Set 2); all succeeded on the tact and category tests with the Set 2 stimuli. Taken together with the findings from the other studies in the series, the present experiment shows that (a) common listener training also establishes the corresponding names in some but not all children, and (b) only children who learn common names categorize; all those who learn only listener behavior fail. This is good evidence in support of the naming account of categorization.     

The shape of thought

When children learn the name of a novel object, they tend to extend that name to other objects similar in shape – a phenomenon referred to as the shape bias. Does the shape bias stem from learned associations between names and categories of objects, or does it derive from more general properties of children's understanding of language and the world? We argue here for the second alternative, presenting evidence that the shape bias emerges early in development, is not limited to names, and is intimately related to how children make sense of categories.     

Early word meanings: The case of object names

It has been claimed that young children use object names overgenerally and undergenerally because they do not have notions of objects of particular kinds, but rather, complexive notions of objects and their habitual actions or locations. However, for overgeneral uses in particular, it is difficult to differentiate word meaning from word use because communicative functions are not explicitly expressed in single-word speech. In the present paper, we identify three types of overgeneral uses, and argue that two of these reflect communicative functions rather than complexive meanings. We obtained production data from 10 children in the single-word period, using a standardized method of recording utterance contexts. Most uses of object names were for appropriate instances of the adult categories. Of the overgeneral uses, most were attributable to communicative functions rather than complexive meanings, and there was no evidence of undergeneral use. The results provide strong evidence that, from the very start, children's object names, like those of adults, apply to objects of particular kinds.     

Improving word learning in children using an errorless technique

The current experiment examined the relative advantage of an errorless learning technique over an errorful one in the acquisition of novel names for unfamiliar objects in typically developing children aged between 7 and 9 years. Errorless learning led to significantly better learning than did errorful learning. Processing speed and vocabulary predicted unique significant variance in errorful learning but not errorless learning, suggesting a possible locus for the errorless advantage. Errorless methods may provide a suitable basis not only for improving language learning but also for improving classroom learning and identifying children who will benefit from this technique.