What's new? Children prefer novelty in referent selection

Determining the referent of a novel name is a critical task for young language learners. The majority of studies on children’s referent selection focus on manipulating the sources of information (linguistic, contextual and pragmatic) that children can use to solve the referent mapping problem. Here, we take a step back and explore how children’s endogenous biases towards novelty and their own familiarity with novel objects influence their performance in such a task. We familiarized 2-year-old children with previously novel objects. Then, on novel name referent selection trials children were asked to select the referent from three novel objects: two previously seen and one completely novel object. Children demonstrated a clear bias to select the most novel object. A second experiment controls for pragmatic responding and replicates this finding. We conclude, therefore, that children’s referent selection is biased by previous exposure and children’s endogenous bias to novelty.     

Rapid fast-mapping abilities in 2-year-olds

Learning a new word consists of two primary tasks that have often been conflated into a single process: referent selection, in which a child must determine the correct referent of a novel label, and referent retention, which is the ability to store this newly formed label-object mapping in memory for later use. In addition, children must be capable of performing these tasks rapidly and repeatedly as they are frequently exposed to novel words during the course of natural conversation. Here we used a preferential pointing task to investigate 2-year-olds’ (N = 72) ability to infer the referent of a novel noun from a single ambiguous exposure and their ability to retain this mapping over time. Children were asked to identify the referent of a novel label on six critical trials distributed throughout the course of a 10-min study involving many familiar and novel objects. On these critical trials, images of a known object and a novel object (e.g., a ball and a nameless artifact constructed in the laboratory) appeared on two computer screens and a voice asked children to “point at the _____ [e.g., glark].” Following label onset, children were allowed only 3 s during which to infer the correct referent, point at it, and potentially store this new word-object mapping. In a final posttest trial, all previously labeled novel objects appeared and children were asked to point to one of them (e.g., “Can you find the glark?”). To succeed, children needed to have initially mapped the novel labels correctly and retained these mappings over the course of the study. Despite the difficult demands of the current task, children successfully identified the target object on the retention trial. We conclude that 2-year-olds are able to fast map novel nouns during a brief single exposure under ambiguous labeling conditions.     

That's More Like It: Multiple Exemplars Facilitate Word Learning

Previous research indicates learning words facilitates categorisation. The current study explores how categorisation affects word learning. In the current study, we investigated whether learning about a category facilitates retention of newly learned words by presenting 2‐year‐old children with multiple referent selection trials to the same object category. In Experiment 1, children either encountered the same exemplar repeatedly or encountered multiple exemplars across trials. All children did very well on the initial task; however, only children who encountered multiple exemplars retained these mappings after a short delay. Experiment 2 replicated and extended this finding by exploring the effect of within‐category variability on children's word retention. Children encountered either narrow or broad exemplars across trials. Again, all children did very well on the initial task; however, only children who encountered narrow exemplars retained mappings after a short delay. Overall, these data offer strong evidence that providing children with the opportunity to compare across exemplars during fast mapping facilitates retention. Copyright © 2013 John Wiley & Sons, Ltd.     

The decontextualization of form and function in the development of pretence

Through the process of decontextualization, the behaviours and objects used in children's pretence become increasingly detached from their real‐life contexts and uses ( Flavell, 1985 ). However, whilst age‐related changes in children's pretence have been reasonably well documented, the relationship between the decontextualization of form and function has yet to be established and the relationship between pretence using substitute objects and pretence without substitute objects remains unclear. To address these issues, 3–8‐year‐old typically developing children (N =84) were shown a series of pretend actions, like writing, enacted at various levels of decontextualization. Children's understanding of each action was assessed. The results revealed three main findings. First, form and function are both equally important in children's comprehension of object substitution pretence. Second, children find actions enacted using substitute objects that are similar to the referent in terms of both their form and function easier to interpret than those performed using decontextualized props – including body‐part‐as‐object (BPO) and imaginary object (IO) gestures – regardless of age. Finally, BPO and IO gestures are of equal complexity and children 5 years and above correctly interpret these gestures more readily than actions involving substitute objects that share no similarity with the referent. These findings are discussed in relation to dual and triune representation problems ( DeLoache, 1995 ; Tomasello, Striano, & Rochat, 1999 ).     

Contextual repetition facilitates word learning via fast mapping

The current study explores whether contextual repetition during fast mapping facilitates word learning. Three-year-old children completed fast mapping and test trials using a touchscreen computer. For half of the children, the non-targets (competitors) repeated across learning trials and for other children there was no repetition. All children received the same test trials. Children who experienced contextual repetition, that is, children for whom the competitors repeated during the initial fast mapping task, demonstrated word learning. These data demonstrate that children's word learning is facilitated by the presence of extraneous yet predictable information in the initial fast mapping task.     

Object individuation and event mapping: developmental changes in infants’ use of featural information

The present research examined the development of 4.5‐ to 7.5‐month‐old infants’ ability to map different‐features occlusion events using a simplified event‐mapping task. In this task, infants saw a different‐features (i.e. egg‐column) event followed by a display containing either one object or two objects. Experiments 1 and 2 assessed infants’ ability to judge whether the egg‐column event was consistent with a subsequent one‐column display. Experiments 3 and 4 examined infants’ ability to judge whether the objects seen in the egg‐column event and those seen in a subsequent display were consistent in their featural composition. At 7.5 and 5.5 months, but not at 4.5 months, the infants successfully mapped the egg‐column event onto the one‐column display. However, the 7.5‐ and 5.5‐month‐olds differed in whether they mapped the featural properties of those objects. Whereas the 7.5‐month‐olds responded as if they expected to see two specific objects, an egg and a column, in the final display the 5.5‐month‐olds responded as if they simply expected to see ‘two objects’. Additional results revealed, however, that when spatiotemporal information specified the presence of two objects, 5.5‐month‐olds succeeded at tagging the objects as being featurally distinct, although they still failed to attach more specific information about what those differences were. Reasons for why the younger infants had difficulty integrating featural information into their object representations were discussed.     

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.

     

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.     

The role of gaze direction and mutual exclusivity in guiding 24‐month‐olds' word mappings

In these studies, we examined how a default assumption about word meaning, the mutual exclusivity assumption and an intentional cue, gaze direction, interacted to guide 24‐month‐olds' object‐word mappings. In Expt 1, when the experimenter's gaze was consistent with the mutual exclusivity assumption, novel word mappings were facilitated. When the experimenter's eye‐gaze was in conflict with the mutual exclusivity cue, children demonstrated a tendency to rely on the mutual exclusivity assumption rather than follow the experimenter's gaze to map the label to the object. In Expt 2, children relied on the experimenter's gaze direction to successfully map both a first label to a novel object and a second label to a familiar object. Moreover, infants mapped second labels to familiar objects to the same degree that they mapped first labels to novel objects. These findings are discussed with regard to children's use of convergent and divergent cues in indirect word mapping contexts.     

Preschoolers' interpretations of gesture: label or action associate?

This study explores a common assumption made in the cognitive development literature that children will treat gestures as labels for objects. Without doubt, researchers in these experiments intend to use gestures symbolically as labels. The present studies examine whether children interpret these gestures as labels. In Study 1 two-, three-, and four-year olds tested in a training paradigm learned gesture–object pairs for both iconic and arbitrary gestures. Iconic gestures became more accurate with age, while arbitrary gestures did not. Study 2 tested the willingness of children aged 40–60 months to fast map novel nouns, iconic gestures and arbitrary gestures to novel objects. Children used fast mapping to choose objects for novel nouns, but treated gesture as an action associate, looking for an object that could perform the action depicted by the gesture. They were successful with iconic gestures but chose objects randomly for arbitrary gestures and did not fast map. Study 3 tested whether this effect was a result of the framing of the request and found that results did not change regardless of whether the request was framed with a deictic phrase (“this one 〈gesture〉”) or an article (“a 〈gesture〉”). Implications for preschool children’s understanding of iconicity, and for their default interpretations of gesture are discussed.     

Tapping into the interplay of lexical and number knowledge using fast mapping: A longitudinal eye-tracking study with two-year-olds

Language skills and mathematical competencies are argued to influence each other during development. While a relation between the development of vocabulary size and mathematical skills is already documented in the literature, this study further examines how children’s ability to map a novel word to an unknown object as well as their ability to retain this word from memory may be related to their knowledge of number words. Twenty-five children were tested longitudinally (at 30 and at 36 months of age) using an eye-tracking-based fast mapping task, the Give-a-Number task, and standardized measures of vocabulary. The results reveal that children’s ability to create and retain a mental representation of a novel word was related to number knowledge at 30 months, but not at 36 months while vocabulary size correlated with number knowledge only at 36 months. These results show that even specific mapping processes are initially related to the acquisition of number words and they speak for a parallelism between the development of lexical and number-concept knowledge despite their semantic and syntactic differences.     

Early development of scaling ability

The map is a small-scaled version of the space it represents. It has been argued that children have difficulty interpreting maps because they do not understand scale relations. Recent research has shown that even preschoolers can solve problems that involve scaling in one dimension. This study examined whether early scaling ability extends to tasks involving two-dimensional maps and referent spaces of different sizes. Results showed that about 60% of the 4-year-olds and 90% of the 5-year-olds tested used distance information presented on a map to locate an object in a two-dimensional spatial layout. Children had more difficulties in solving mapping tasks with a larger referent space. This decrease in accuracy as a function of space size on the mapping task was greater than would have been expected on the basis of performance on a parallel nonmapping task. The results are discussed in terms of their implications for the mechanisms underlying early scaling ability.     

Developmental changes in children's understanding of the similarity between photographs and their referents

In a series of three experiments, we investigated the development of children's understanding of the similarities between photographs and their referents. Based on prior work on the development of analogical understanding (e.g. Gentner & Rattermann, 1991), we suggest that the appreciation of this relation involves multiple levels. Photographs are similar to their referents both in terms of the constituent objects and in terms of the relations among these objects. We predicted that children would appreciate object similarity (whether photographs depict the same objects as in the referent scene) before they would appreciate relational similarity (whether photographs depict the objects in the same spatial positions as in the referent scene). To test this hypothesis, we presented 3-, 4-, 5-, 6-, and 7-year-old children and adults with several candidate photographs of an arrangement of objects. Participants were asked to choose which of the photographs was 'the same' as the arrangement. We manipulated the types of information the photographs preserved about the referent objects. One set of photographs did not preserve the object properties of the scene. Another set of photographs preserved the object properties of the scene, but not the relational similarity, such that the original objects were depicted but occupied different spatial positions in the arrangement. As predicted, younger children based their choices of the photographs largely on object similarity, whereas older children and adults also took relational similarity into account. Results are discussed in terms of the development of children's appreciation of different levels of similarity.     

Effect of stimulus configuration on spatial judgments in search tasks

Although children over one year of age are able to code spatial information with respect to objects other than the self, there are many instances in which the self is inappropriately used as a spatial referent by children between 2 and 4 years of age. L. G. Braine and R. A. Eder (1983, Developmental Psychology, 19, 45-55) found that, in a search task, the nature of the array influenced the spatial referent used by 2-year-old children. The present work investigated the effect of varying the number, size, and arrangement of boxes in the array. It was found that only the number of boxes defining the left and right sides of the array influenced performance; that is, multiple boxes were associated with the use of external objects as spatial referents. These results were interpreted as stemming from the tendency of young children to code the location of an object with respect to nearby objects. This tendency would lead to the use of adjacent boxes and environmental objects as spatial referents for the multiple-box side, and the use of the self as a spatial referent for the single-box side.     

Fast mapping of multiple words: Insights into when “the information provided” does and does not equal “the information perceived”

A candidate process for explaining the rapid vocabulary acquisition during the preschool years is “fast mapping,” children's ability to sketch partial maps of a word's meaning after brief exposure. The present study examines this process for learning multiple words, testing the hypothesis that children's attention to the information critical for quickly mapping multiple words onto their referents depends on the alternatives available when the words are introduced. Fifty-eight 40-month-old children participated in one of two conditions. In both conditions, each trial for novel Word #1 presented a novel object and three familiar ones. The conditions differed in the object choices presented when novel Word #2 was introduced. Although the same information was available to children in both conditions, younger children showed significantly better learning of the new words in the successive condition than in the concurrent condition. Implications of this for age-related differences and for teaching strategies are discussed.     

Acquiring experiential traces in word-referent learning

In two experiments, we investigated the activation of perceptual representations of referent objects during word processing. In both experiments, participants learned to associate pictures of novel three-dimensional objects with pseudowords. They subsequently performed a recognition task (Experiment 1) or a naming task (Experiment 2) on the object names while being primed with different types of visual stimuli. Only the stimuli that the participants had encountered as referent objects during the training phase facilitated recognition or naming responses. New stimuli did not facilitate the processing of object names, even if they matched a schematic or prototypical representation of the referent object that the participants might have abstracted during word-referent learning. These results suggest that words learned by way of examples of referent objects are associated with experiential traces of encounters with these objects.     

Consolidation of vocabulary is associated with sleep in children

Although the acquisition of a novel word is apparently rapid, adult research suggests that integration of novel and existing knowledge (measured by engagement in lexical competition) requires sleep‐associated consolidation. We present the first investigation of whether a similar time‐course dissociation characterizes word learning across development. Consistent with previous research but counter to adults, 7–12‐year‐olds showed sleep‐associated consolidation effects in declarative but not procedural memory. Nevertheless, the relationship between sleep and word learning in children was remarkably similar to the pattern for adults. Following exposure to nonword competitors (e.g. biscal) in the a.m. or p.m., children’s ability to recognize and recall the nonwords improved only after sleep (after approximately 12‐hrs for the p.m. group and 24‐hrs for the a.m. group), with performance stable 1 week later. Novel nonwords only induced lexical competition effects after sleep. These findings suggest that children utilize a dual memory system when acquiring and integrating new vocabulary and highlight sleep as integral to this process. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=8mm8SDUXw_0&feature=plcp .     

The effects of perceptual similarity and category membership on early word-referent identification

We investigated the impact of perceptual and categorical relatedness between a target and a distracter object on early referent identification in infants and adults. In an intermodal preferential looking (IPL) task, participants looked at a target object paired with a distracter object that could be perceptually similar or dissimilar and drawn from the same or different global category. The proportion of target looking measures revealed that infants and adults were sensitive to the interplay between category membership and perceptual similarity. Online latency measures demonstrated an advantage for perceptually dissimilar items regardless of their categorical status, indicating that different IPL measures index different processes during target identification. Results suggest that perceptual similarity and category membership of the objects lead to competition effects in word recognition and referent identification in both adults and infants and that lexical categorization and nonlinguistic categorization processes are closely related during infancy.     

Factors affecting children's graphic symbol use in the third year: Language,similarity, and iconicity

The question addressed in this study is whether the claim that children understand the symbolic status of pictures by the middle of their third year is an overestimate of their ability. Specifically, we asked whether children use language if possible to facilitate their performance in graphic symbolic tasks. Language (availability of verbal labels) was manipulated along with iconicity (degree of resemblance between symbol and referent) and perceptual similarity (between choice items) in a series of four experiments. Children 2.5 and 3 years old were presented with a graphic symbol for 4 s and immediately asked to choose the object depicted (referent) from two choice objects. In Study 1, degree of iconicity between picture and referent was varied and both choice objects had the same verbal label. The 2.5-year-olds failed to use any pictures or replicas as symbols. The 3-year-olds performed well with all types of symbols and better with highly iconic symbols. In Study 2, verbal label availability was manipulated by presenting choice objects having the same or different labels and by varying familiarity of labels. The 2.5-year-olds performed at chance when verbal labels were unavailable but above chance when they were available. The 3-year-olds were above chance in all conditions but performed less well when verbal labels were unavailable. Study 3 confirmed that young children use language to mediate picture symbol use. When 2.5-year-olds were provided with subordinate verbal labels in the matching task, subsequent performance was good even when choice objects had the same basic level verbal label. In Study 4, verbal label availability was contrasted with perceptual similarity between choice objects. When verbal labels could be used and choice objects were dissimilar, performance was best, and when verbal labels could not be used and choice objects were similar, it was worst. The results suggest that children's developing understanding of the symbolic function of pictures is tenuous in the third year, and is supported by their use of verbal labels.     

Children remember words from ignorant speakers but do not attach meaning: evidence from event‐related potentials

Although we know much about the conditions under which children demonstrate selective social learning, we have a limited understanding of the cognitive mechanisms by which children's selectivity manifests. Here, we report findings from a brain electrophysiological (ERP) study designed to determine the extent to which words presented by ignorant speakers were later both familiar to children and associated with semantic meaning. Forty‐eight children (mean age = 6.5 years) first experienced novel word training from either a knowledgeable or an ignorant speaker. Children's ERPs were subsequently recorded as they heard a recording of the speaker using the novel word, followed by a picture of either the object the word was paired with during training (congruent) or a distractor object that was also present during training (incongruent). Children trained by a knowledgeable speaker showed both N200 and N400 effects to the incongruent word–referent pairings, thereby suggesting that the novel words were both familiar and bore a semantic association. In contrast, children trained by an ignorant speaker demonstrated only the N200 effect, thereby suggesting that the word–referent links were familiar, but not associated with semantic meaning. These findings provide evidence that selective word learning involves the disruption of processes specifically associated with semantic consolidation of word learning events.