Slowing Down Fast Mapping: Redefining the Dynamics of Word Learning

Children build their vocabularies in noisy environments: The necessity of a cross-disciplinary approach to understand word learning

Research within the language sciences has informed our understanding of how children build vocabulary knowledge especially during early childhood and the early school years. However, to date, our understanding of word learning in children is based primarily on research in quiet laboratory settings. The everyday environments that children inhabit such as schools, homes, and day cares are typically noisy. To better understand vocabulary development, we need to understand the effects of background noise on word learning. To gain this understanding, a cross-disciplinary approach between researchers in the language and hearing sciences in partnership with parents, educators, and clinicians is ideal. Through this approach we can identify characteristics of effective vocabulary instruction that take into account the background noise present in children's learning environments. Furthermore, we can identify characteristics of children who are likely to struggle with learning words in noisy environments. For example, differences in vocabulary knowledge, verbal working memory abilities, and attention skills will likely influence children's ability to learn words in the presence of background noise. These children require effective interventions to support their vocabulary development which subsequently should support their ability to process and learn language in noisy environments. Overall, this cross-disciplinary approach will inform theories of language development and inform educational and intervention practices designed to support children's vocabulary development. This article is categorized under: Psychology > Language Psychology > Learning Psychology > Theory and Methods.

Can Infants Retain Statistically Segmented Words and Mappings Across a Delay?

Infants are sensitive to statistics in spoken language that aid word-form segmentation and immediate mapping to referents. However, it is not clear whether this sensitivity influences the formation and retention of word-referent mappings across a delay, two real-world challenges that learners must overcome. We tested how the timing of referent training, relative to familiarization with transitional probabilities (TPs) in speech, impacts English-learning 23-month-olds' ability to form and retain word-referent mappings. In Experiment 1, we tested infants' ability to retain TP information across a 10-min delay and use it in the service of word learning. Infants successfully mapped high-TP but not low-TP words to referents. In Experiment 2, infants readily mapped the same words even when they were unfamiliar. In Experiment 3, high- and low-TP word-referent mappings were trained immediately after familiarization, and infants readily remembered these associations 10 min later. In sum, although 23-month-old infants do not need strong statistics to map word forms to referents immediately, or to remember those mappings across a delay, infants are nevertheless sensitive to these statistics in the speech stream, and they influence mapping after a delay. These findings suggest that, by 23 months of age, sensitivity to statistics in speech may impact infants' language development by leading word forms with low coherence to be poorly mapped following even a short period of consolidation.

The phonological congruency modulated long-term form priming of Chinese characters

Elucidating the interaction between lexical processing and word learning is essential for a complete understanding of the underlying mechanisms of each of them. Long-term priming for words reflects an interplay between lexical processing and word learning. Although robust long-term priming effects have been found between two occurrences of the same word and between semantically similar words, it remains unclear whether long-term priming between orthographically similar words (i.e., long-term form priming) is a reliable effect. Following the theoretical analysis based on the connectionist framework, we articulated the possibility that long-term form priming might be modulated by the phonological congruency between the prime and target words, and that if this modulator was under control, reliable effects of long-term form priming would emerge. However, this hypothesis has not been adequately tested empirically. The present study tested this hypothesis by using Chinese phonograms and the phonetic radicals embedded in them as the prime and target items. In three experiments that varied in the types of stimuli and testing tasks, we consistently found that when the prime and target had the same phonology, naming the prime facilitated later processing of the target, while when they had different phonologies, the priming effect was inhibitory. These observations were consistent with the connectionist account of long-term priming for words. Our findings help confirm the reliability, generalizability, and robustness of long-term form priming and elucidate its underlying mechanisms, and suggesting promising future directions on the interactions between lexical processing and word learning.

The Development of Speaking and Singing in Infants May Play a Role in Genomics and Dementia in Humans

The development of the central auditory system, including the auditory cortex and other areas involved in processing sound, is shaped by genetic and environmental factors, enabling infants to learn how to speak. Before explaining hearing in humans, a short overview of auditory dysfunction is provided. Environmental factors such as exposure to sound and language can impact the development and function of the auditory system sound processing, including discerning in speech perception, singing, and language processing. Infants can hear before birth, and sound exposure sculpts their developing auditory system structure and functions. Exposing infants to singing and speaking can support their auditory and language development. In aging humans, the hippocampus and auditory nuclear centers are affected by neurodegenerative diseases such as Alzheimer's, resulting in memory and auditory processing difficulties. As the disease progresses, overt auditory nuclear center damage occurs, leading to problems in processing auditory information. In conclusion, combined memory and auditory processing difficulties significantly impact people's ability to communicate and engage with their societal essence.

The timescales of word learning in children with language delays: In-the-moment mapping, retention, and generalization

Learning new words and, subsequently, a lexicon, is a time-extended process requiring encoding of word-referent pairs, retention of that information, and generalization to other exemplars of the category. Some children, however, fail in one or more of these processes resulting in language delays. The present study examines the abilities of children who vary in vocabulary size (including both children with normal language (NL) and late talking (LT) children) across multiple timescales/processes - known and novel word mapping, novel word retention, and novel noun generalization. Results indicate that children with lower language skills suffer from deficits in quick in-the-moment mapping of known words compared to their NL peers, but age and vocabulary size rather than normative vocabulary ranking or NL/LT status better predicts performance on retention and generalization processes. Implications for understanding language development as a holistic process with multiple interacting variables are discussed.

Understanding preschoolers' word learning success in different scenarios: disambiguation meets statistical learning and eBook reading

Children's ability to learn new words during their preschool years is crucial for further academic success. Previous research suggests that children rely on different learning mechanisms to acquire new words depending on the available context and linguistic information. To date, there is limited research integrating different paradigms to provide a cohesive view of the mechanisms and processes involved in preschool children's word learning. We presented 4 year-old children (n = 47) with one of three different novel word-learning scenarios to test their ability to connect novel words to their correspondent referents without explicit instruction to do so. The scenarios were tested with three exposure conditions of different nature: (i) mutual exclusivity-target novel word-referent pair presented with a familiar referent, prompting fast-mapping via disambiguation, (ii) cross-situational-target novel word-referent pair presented next to an unfamiliar referent prompting statistically tracking the target pairs across trials, and (iii) eBook - target word-referent pairs presented within an audio-visual electronic storybook (eBook), prompting inferring meaning incidentally. Results show children succeed at learning the new words above chance in all three scenarios, with higher performance in eBook and mutual exclusivity than in cross-situational word learning. This illustrates children's astounding ability to learn while coping with uncertainty and varying degrees of ambiguity, which are common in real-world situations. Findings extend our understanding of how preschoolers learn new words more or less successfully depending on specific word learning scenarios, which should be taken into account when working on vocabulary development for school readiness in the preschool years.

Temperament and children's accuracy and attention during word learning

When hearing a novel word, children typically rule out familiar objects and assume a speaker is referring to a novel object. This strategy is known as fast mapping, and young children use this with a high degree of accuracy. However, not all children engage in fast mapping to the same extent and temperament can play a role. Shyness is associated with poorer fast mapping and less attention to target objects, which is associated with poorer retention (Hilton et al., 2019; Hilton & Westermann, 2017). We further investigated the relationship between temperament and fast mapping by presenting 2.5-year-old children with 8 familiar target fast mapping trials and 4 novel target trials presented twice. We considered two temperamental dimensions: approachability due to its similarity to shyness; and reactivity, which could predict children's capacity to engage during fast mapping. We found an association between approachability and fast mapping accuracy the second time children fast-mapped novel targets, and approachability was associated with greater retention accuracy. Reactivity predicted proportions of target looking during fast mapping with less reactive temperament scores associated with greater focus on targets. This provides support for a relationship between two dimensions of temperament and fast mapping and retention. Approachability may be associated with a further opportunity to fast map and memory for novel words, and/or how willing children are to guess the targets. Reactivity may be associated with the capacity to focus during word learning situations. Different aspects of temperament could have implications for children's capacity to disambiguate and learn words.

Keep the Ball Rolling: Sustained Multiturn Conversational Episodes Are Associated With Child Language Ability

PURPOSE

The purpose of this study was to examine the relationship between interaction quality and child language ability. We focused on one promising interaction quality indicator-the rate of multiturn conversational episodes. We also explored whether the relationship between rate of single conversational turns and language ability changed when the child's nonverbal behaviors were considered in addition to verbal conversational turns. To limit the potential of socioeconomic status as a confounder, participants included only families living in underresourced households.

METHOD

Secondary analyses were conducted using baseline data (N = 41 dyads enrolled, N = 27 analyzed) from a longitudinal study. All families were living in low-income households (i.e., below 200% of the Federal Poverty Level) and 12 were English-Spanish bilingual (15 English-only). Mothers and their children (13 to 27 months) participated in video-recorded play and reading interactions at home. Trained observers transcribed and coded the child's and caregiver's verbal and nonverbal behaviors. Linear regression models examined the relationship between the number of conversational turns and child language ability.

RESULTS

Child language ability was significantly and positively associated with the number of verbal-nonverbal single turns and multiturn conversational episodes, but not single verbal-only turns.

CONCLUSIONS

For children still acquiring language, it is important to account for nonverbal contributions to conversation. Child language ability was significantly and positively associated only with the conversational turn variables that included the child's nonverbal behaviors. Further investigation is needed to understand whether number of turns within conversational episodes is a better indicator of interaction quality than sheer number of conversational turns. Implications for caregiver-implemented interventions are discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20452575.

Evaluating the Effect of Rich Vocabulary Instruction and Retrieval Practice on the Classroom Vocabulary Skills of Children With (Developmental) Language Disorder

PURPOSE

Learning new vocabulary has been identified as a challenge for students with (developmental) language disorder ((D)LD). In this study, we evaluate the effects of two active learning methods, (a) retrieval practice (RP) and (b) rich vocabulary instruction (RVI), in a group of students with (D)LD in secondary school.

METHOD

A quasi-experimental counterbalanced within-subject design was used to compare and evaluate the effect of RP and RVI on learning Tier 2 vocabulary, with target and control words as dependent measures. Eleven students with (D)LD (M _age = 14.9 years) attending a language unit participated. RP and RVI were implemented in regular classroom activities during 16 lessons (eight lessons/instructional condition). Learning was assessed by comparing performance on a pretest session 1-2 weeks prior, with posttest performance 1 week after each instructional condition.

RESULTS

The learning gain for RP was superior to that for RVI, both with respect to the Bayesian probabilistic estimations for target words relative to control words and in direct comparison with RVI. Only weak evidence was found for RVI with respect to the Bayesian probabilistic estimations for target words relative to control words.

CONCLUSIONS

All participants showed positive learning gains following RP, whereas the outcome for RVI was more diverse. This initial work suggests that RP promotes larger learning gains relative to RVI and promotes learning across language profiles. This study extends previous studies by exploring the implementation of RP in regular classroom activities and by using more complex to-be-learned material (Tier 2 words).

Visual perceptual salience and novel referent selection in children with and without autism spectrum disorder

BACKGROUND & AIMS

Many young children with autism spectrum disorder (ASD) demonstrate striking delays in early vocabulary development. Experimental studies that teach the meanings of novel nonwords can determine the effects of linguistic and attentional factors. One factor that may affect novel referent selection in children with ASD is visual perceptual salience-how interesting (i.e., striking) stimuli are on the basis of their visual properties. The goal of the current study was to determine how the perceptual salience of objects affected novel referent selection in children with ASD and children who are typically developing (TD) of similar ages (mean age 3-4 years).

METHODS

Using a screen-based experimental paradigm, children were taught the names of four unfamiliar objects: two high-salience objects and two low-salience objects. Their comprehension of the novel words was assessed in low-difficulty and high-difficulty trials. Gaze location was determined from video by trained research assistants.

RESULTS

Contrary to initial predictions, findings indicated that high perceptual salience disrupted novel referent selection in the children with ASD but facilitated attention to the target object in age-matched TD peers. The children with ASD showed no significant evidence of successful novel referent selection in the high-difficulty trials. Exploratory reaction time analyses suggested that the children with autism showed "stickier" attention-had more difficulty disengaging (i.e., looking away)-from high-salience distracter images than low-salience distracter images, even though the two images were balanced in salience for any given test trial.

CONCLUSIONS AND CLINICAL IMPLICATIONS

These findings add to growing evidence that high perceptual salience has the potential to disrupt novel referent selection in children with ASD. These results underscore the complexity of novel referent selection and highlight the importance of taking the immediate testing context into account. In particular, it is important to acknowledge that screen-based assessments and screen-based learning activities used with children with ASD are not immune to the effects of lower level visual features, such as perceptual salience.

Prior Exposure and Toddlers' Sleep-Related Memory for Novel Words

Children can easily link a novel word to a novel, unnamed object—something referred to as fast mapping. Despite the ease and speed with which children do this, their memories for novel fast-mapped words can be poor unless they receive memory supports such as further exposure to the words or sleep. Axelsson, Swinton, Winiger, and Horst (2018) found that 2.5-year-old children who napped after fast mapping had better retention of novel words than children who did not nap. Retention declined for those who did not nap. The children received no memory supports and determined the word-object mappings independently. Previous studies report enhanced memories after sleeping in children and adults, but the napping children’s retention in the Axelsson et al. study remained steady across time. We report a follow-up investigation where memory supports are provided after fast mapping to test whether memories would be enhanced following napping. Children’s retention of novel words improved and remained greater than chance; however, there was no nap effect with no significant difference between the children who napped and those who did not. These findings suggest that when memory supports are provided, retention improves, and the word–object mappings remain stable over time. When memory traces are weak and labile, such as after fast mapping, without further memory supports, sleeping soon after helps stabilise and prevent decay of word–object mappings.

Improvements of Statistical Learning Skills Allow Older Children to Go Beyond Single-Hypothesis Testing When Learning Words

Children learn words in ambiguous situations, where multiple objects can potentially be referents for a new word. Yet, researchers debate whether children maintain a single word-object hypothesis - and revise it if falsified by later information - or whether children establish a network of word-object associations whose relative strengths are modulated with experience. To address this issue, we presented 4- to 12-year-old children with sets of mutual exclusivity (fast-mapping) trials: offering them with obvious initial hypotheses (that the novel object is the referent for the novel word). We observe that children aged six years and above, despite showing a novelty bias and retaining this novel word - novel object association, also formed an association between the novel word and the name-known object, thereby suggesting that older children attend to more than one word-object association, in a manner similar to associative learning. We discuss our findings in the context of competing theoretical accounts related to word learning.

Patterns of mutual exclusivity and retention: A study of monolingual and bilingual 2-year-olds

When children learn their native language, they tend to treat objects as if they only have one label-a principle known as mutual exclusivity. However, bilingual children are faced with a different cognitive challenge-they need to learn to associate two labels with one object. In the present study, we compared bilingual and monolingual 24-month-olds' performance on a challenging and semi-naturalistic forced-choice referent selection task and retention test. Overall, both language groups performed similarly on referent selection but differed on retention. Specifically, while monolingual infants showed some retention, bilingual infants performed at chance and significantly worse than their monolingual peers.

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.

Competing Perceptual Salience in a Visual Word Recognition Task Differentially Affects Children With and Without Autism Spectrum Disorder

Differences in visual attention have long been recognized as a central characteristic of autism spectrum disorder (ASD). Regardless of social content, children with ASD show a strong preference for perceptual salience-how interesting (i.e., striking) certain stimuli are, based on their visual properties (e.g., color, geometric patterning). However, we do not know the extent to which attentional allocation preferences for perceptual salience persist when they compete with top-down, linguistic information. This study examined the impact of competing perceptual salience on visual word recognition in 17 children with ASD (mean age 31 months) and 17 children with typical development (mean age 20 months) matched on receptive language skills. A word recognition task presented two images on a screen, one of which was named (e.g., Find the bowl!). On Neutral trials, both images had high salience (i.e., were colorful and had geometric patterning). On Competing trials, the distracter image had high salience but the target image had low salience, creating competition between bottom-up (i.e., salience-driven) and top-down (i.e., language-driven) processes. Though both groups of children showed word recognition in an absolute sense, competing perceptual salience significantly decreased attention to the target only in the children with ASD. These findings indicate that perceptual properties of objects can disrupt attention to relevant information in children with ASD, which has implications for supporting their language development. Findings also demonstrate that perceptual salience affects attentional allocation preferences in children with ASD, even in the absence of social stimuli. LAY SUMMARY: This study found that visually striking objects distract young children with autism spectrum disorder (ASD) from looking at relevant (but less striking) objects named by an adult. Language-matched, younger children with typical development were not significantly affected by this visual distraction. Though visual distraction could have cascading negative effects on language development in children with ASD, learning opportunities that build on children's focus of attention are likely to support positive outcomes.

Processes and pathways in development via digital media: Examples from word learning

Word learning unfolds over multiple, cascading pathways which support in-the-moment processing and learning. The process is refined with each exposure to a word, and exposures to new words occur across a variety of forms and contexts. However, as children are exposed to more and more digital media, the ways in which children encounter, learn, and build on their vocabulary is also shifting. These shifts represent changes in context, content, and at the level of the child that can lead to negative outcomes. Less work, however, has discussed what these differences mean for how things change in the underlying developmental cascade and learning processes. Here, we suggest that the increasing presence of digital media may shift the developmental pathways for learning (the chain of events that support future learning) but not necessarily the developmental processes (the mechanisms underlying learning). Moreover, the interaction of the two may lead to different behavior and outcomes for learning in a digital era. We argue it is imperative for researchers to not only study how digital media differs from everyday learning, but directly measure if the well-worn pathways, processes, and variables found with decades of research with real items translate to a digital media era.

Linking disambiguation and retention in a developmental eye-tracking study with monolingual and multilingual children

The disambiguation effect, also referred to as process of elimination, occurs during word learning, whereby novel words are mapped onto new referents, precluding the application of a novel label to a familiar object. Prior studies showed that the emergence and use of disambiguation can be affected by children's vocabulary growth and linguistic experience, such as growing up with more than one language. To test this, we investigated (a) whether monolingual and multilingual children disambiguated a novel word-object mapping, (b) whether they retained a trained, previously seen word-object mapping, (c) whether they retained the novel fast-mapped word-object mapping, and (d) whether and how age, English vocabulary size, and language background modulated disambiguation and retention. Lastly, we tested (e) whether children who disambiguated also retained better. Eye-tracking data from 18- to 30-month-old monolingual children (n = 43) and multilingual children (n = 40) were collected. A looking-while-listening paradigm with two objects included two familiar items, one novel item, and one trained item. Mixed-effect models reported that vocabulary size predicted the outcome of mapping and retention better than age. Monolingual children's accuracy on disambiguation trials was high from the start, whereas multilingual children started to disambiguate later as their vocabulary grew. Only monolingual children performed above chance level on retaining the novel label. Lastly, the use of disambiguation improved retention for monolingual children but not for multilingual children. This research corroborates that disambiguation should be regarded as a mechanism facilitating default fast mapping rather than fully fledged learning. Vocabulary growth leading to an increase in disambiguation supports the notion that the disambiguation effect stems from prior episodes of learning.

Learning words in space and time: Contrasting models of the suspicious coincidence effect

In their 2007b Psychological Review paper, Xu and Tenenbaum found that early word learning follows the classic logic of the "suspicious coincidence effect:" when presented with a novel name ('fep') and three identical exemplars (three Labradors), word learners generalized novel names more narrowly than when presented with a single exemplar (one Labrador). Xu and Tenenbaum predicted the suspicious coincidence effect based on a Bayesian model of word learning and demonstrated that no other theory captured this effect. Recent empirical studies have revealed, however, that the effect is influenced by factors seemingly outside the purview of the Bayesian account. A process-based perspective correctly predicted that when exemplars are shown sequentially, the effect is eliminated or reversed (Spencer, Perone, Smith, & Samuelson, 2011). Here, we present a new, formal account of the suspicious coincidence effect using a generalization of a Dynamic Neural Field (DNF) model of word learning. The DNF model captures both the original finding and its reversal with sequential presentation. We compare the DNF model's performance with that of a more flexible version of the Bayesian model that allows both strong and weak sampling assumptions. Model comparison results show that the dynamic field account provides a better fit to the empirical data. We discuss the implications of the DNF model with respect to broader contrasts between Bayesian and process-level models.

The temporal structure of naming events differentially affects children's and adults' cross-situational word learning

To acquire novel words, learners often need to integrate information about word meanings across ambiguous learning events distributed in time. How does the temporal structure of those word learning events affect what learners encode? How do the effects of temporal structure differ in children and adults? In the current experiments, we asked how 4- to 7-year-old children's (N = 110) and adults' (N = 90) performance on a cross-situational word learning task is influenced by the temporal distribution of learning events. We tested participants in three training conditions, manipulating the number of trials that separated naming events for specific objects. In the Unstructured condition, the temporal distribution was varied; in the Massed condition, naming events occurred with few interleaved trials; and in the Interleaved condition, naming events occurred with many interleaved trials. Adults showed substantially larger benefits from the Massed condition than children, whereas children were equally successful at learning in the Massed and Interleaved conditions. These results provide evidence that adults differ from children in how they exploit temporal structure during cross-situational word learning.

The Advantages of Retrieval-Based and Spaced Practice: Implications for Word Learning in Clinical and Educational Contexts

Purpose Researchers in the cognitive sciences have identified several key training strategies that support good encoding and retention of target information. These strategies are retrieval-based practice, also known as learning through testing, and spaced practice. The recent resurgence of research on retrieval-based and spaced practice has been extended to investigate the effectiveness of these strategies to support learning in individuals with language disorders. The purpose of the current article is to review key principles of retrieval-based and spaced practice that can be used to support word learning in individuals within clinical and educational contexts. Conclusion Current research provides evidence that principles of retrieval-based and spaced practice can enhance word learning for individuals with language disorders. Current research provides guidance for clinicians on how to implement these strategies both within and across sessions to support encoding and retention of target information. Additional research should be conducted to provide a better understanding of how to optimize encoding and retention in clinical and educational contexts. Most notably, research that examines long-term retention after interventions are withdrawn would further our understanding of how these principles can be optimally applied to improve outcomes for individuals with language disorders.

When slowing down processing helps learning: Lexico-semantic structure supports retention, but interferes with disambiguation of novel object-label mappings

This project explores how children disambiguate and retain novel object-label mappings in the face of semantic similarity. Burgeoning evidence suggests that semantic structure in the developing lexicon promotes word learning in ostensive contexts, whereas other findings indicate that semantic similarity interferes with and temporarily slows familiar word recognition. This project explores how these distinct processes interact when mapping and retaining labels for novel objects (i.e., low-frequency objects that are unfamiliar to toddlers) via disambiguation from a semantically similar familiar referent in 24-month-olds (N = 65). Toddlers' log-adjusted looking to labeled target objects (relative to distractor objects) was measured in three conditions: Familiar trials (familiar label spoken while viewing semantically related familiar and novel objects), Disambiguation trials (unfamiliar label spoken while viewing semantically similar familiar and unfamiliar object), and Retention trials (unfamiliar label spoken while viewing novel object pairs). Toddlers' individual vocabulary structure was then compared to performance on each condition. Vocabulary structure was measured at two levels: category-level structure (semantic density) for experimental items, and lexicon-level structure (global clustering coefficient). The findings suggest, consistent with prior results, that semantic density interfered with known word recognition, and facilitated unfamiliar word retention. Children did not show a significant novel word preference during disambiguation, and disambiguation behavior was not impacted by semantic structure. These findings connect seemingly disparate mechanisms of semantic interference in processing and semantic leveraging in word learning. Semantic interference momentarily slows word recognition and resolution of referential uncertainty for novel label-object mappings. Nevertheless, this slowing might support retention by enabling comparison between related objects.

Toddlers' fast-mapping from noise-vocoded speech

The ability to recognize speech that is degraded spectrally is a critical skill for successfully using a cochlear implant (CI). Previous research has shown that toddlers with normal hearing can successfully recognize noise-vocoded words as long as the signal contains at least eight spectral channels [Newman and Chatterjee. (2013). J. Acoust. Soc. Am. 133(1), 483-494; Newman, Chatterjee, Morini, and Remez. (2015). J. Acoust. Soc. Am. 138(3), EL311-EL317], although they have difficulty with signals that only contain four channels of information. Young children with CIs not only need to match a degraded speech signal to a stored representation (word recognition), but they also need to create new representations (word learning), a task that is likely to be more cognitively demanding. Normal-hearing toddlers aged 34 months were tested on their ability to initially learn (fast-map) new words in noise-vocoded stimuli. While children were successful at fast-mapping new words from 16-channel noise-vocoded stimuli, they failed to do so from 8-channel noise-vocoded speech. The level of degradation imposed by 8-channel vocoding appears sufficient to disrupt fast-mapping in young children. Recent results indicate that only CI patients with high spectral resolution can benefit from more than eight active electrodes. This suggests that for many children with CIs, reduced spectral resolution may limit their acquisition of novel words.

Novel word learning deficits in infants at family risk for dyslexia

Children of reading age diagnosed with dyslexia show deficits in reading and spelling skills, but early markers of later dyslexia are already present in infancy in auditory processing and phonological domains. Deficits in lexical development are not typically associated with dyslexia. Nevertheless, it is possible that early auditory/phonological deficits would have detrimental effects on the encoding and storage of novel lexical items. Word-learning difficulties have been demonstrated in school-aged dyslexic children using paired associate learning tasks, but earlier manifestations in infants who are at family risk for dyslexia have not been investigated. This study assessed novel word learning in 19-month-old infants at risk for dyslexia (by virtue of having one dyslexic parent) and infants not at risk for any developmental disorder. Infants completed a word-learning task that required them to map two novel words to their corresponding novel referents. Not at-risk infants showed increased looking time to the novel referents at test compared with at-risk infants. These findings demonstrate, for the first time, that at-risk infants show differences in novel word-learning (fast-mapping) tasks compared with not at-risk infants. Our findings have implications for the development and consolidation of early lexical and phonological skills in infants at family risk of later dyslexia.

Sometimes it is better to know less: How known words influence referent selection and retention in 18- to 24-month-old children

Young children are surprisingly good word learners. Despite their relative lack of world knowledge and limited vocabularies, they consistently map novel words to novel referents and, at later ages, show retention of these new word-referent pairs. Prior work has implicated the use of mutual exclusivity constraints and novelty biases, which require that children use knowledge of well-known words to disambiguate uncertain naming situations. The current study, however, presents evidence that weaker vocabulary knowledge during the initial exposure to a new word may be better for retention of new mappings. Children aged 18-24 months selected referents for novel words in the context of foil stimuli that varied in their lexical strength and novelty: well-known items (e.g., shoe), just-learned weakly known items (e.g., wif), and completely novel items. Referent selection performance was significantly reduced on trials with weakly known foil items. Surprisingly, however, children subsequently showed above-chance retention for novel words mapped in the context of weakly known competitors compared with those mapped with strongly known competitors or with completely novel competitors. We discuss implications for our understanding of word learning constraints and how children use known words and novelty during word learning.

Discontinuity of Reference Hinders Children's Learning of New Words

When referring to objects, adults package words, sentences, and gestures in ways that shape children's learning. Here, to understand how continuity of reference shapes word learning, an adult taught new words to 4-year-old children (N = 120) using either clusters of references to the same object or no sequential references to each object. In three experiments, the adult used a combination of labels and other object references, which provided informative discourse (e.g., This is small and green), neutral discourse (e.g., This is really great), or no verbal discourse. Switching verbal references from one object to another interfered with learning relative to providing clustered references to a particular object, revealing that discontinuity in discourse hinders children's encoding of new words.

Promoting Low-Income Preschoolers' Vocabulary Learning From Educational Media: Does Repetition Support Memory for Learned Word Knowledge?

Children from diverse backgrounds are able to learn new words from educational media. However, learning is often partial and fragile, leaving much room for uncovering strategies that can increase the efficacy of educational media in supporting children's vocabulary knowledge. The present study investigated one such strategy—repeated viewing of educational media—in a sample of low-income preschoolers. One hundred thirty one preschoolers were randomly assigned to view an educational media clip teaching three vocabulary words in one of three conditions: (a) once, (b) three times in immediate succession (massed repetition), or (c) three times with views spaced 1 hour apart (spaced repetition). Children completed a target vocabulary assessment both immediately after the final view and 1 week later. Results indicate that certain types of word knowledge were supported by repetition, particularly spaced repetition. Children also effectively retained the vocabulary knowledge they acquired from educational media over a 1-week period in all conditions. This suggests that educational media is a strong platform for teaching low-income preschoolers new words, and that spaced repetition might further support low-income preschoolers' vocabulary learning.

Visual and verbal semantic productions in children with ASD, DLD, and typical language

PURPOSE

Associations between visual and verbal input allow children to form, augment, and refine their semantic representations within their mental lexicons. However, children with autism spectrum disorder (ASD) and with developmental language disorder (DLD; also known as specific language impairment) process visual and verbal information differently than their typically developing peers, which may impact how they incorporate visual and verbal features into their semantic representations. The purpose of this exploratory study was to investigate how children with ASD and DLD use visually and verbally presented input to produce semantic representations of newly learned words.

METHOD

Semantic features produced by 36 school-aged children (12 with ASD, 12 with DLD, and 12 with typical language development) were extracted from previously collected novel word definitions and coded based on their initial presentation modality (either visual, verbal, or both in combination) during an extended novel word learning paradigm. These features were then analyzed to explore group differences in the use of visual and verbal input.

RESULTS

The children with ASD and DLD produced significantly more visually-presented semantic features than their typical peers in their novel word definitions. There were no differences between groups in the proportion of semantic features presented verbally or via both modalities in combination. Also, the children increased their production of semantic features presented via both modalities combined across the sessions; this same increase in production was not observed for the semantic features taught in either the visual or verbal modality alone.

CONCLUSION

Children with ASD and DLD benefit from visually presented semantic information, either in isolation or combined with verbal input, during tasks of word learning. Also, the reinforcement of combined visual-verbal input appears to enhance semantic learning over time.

The Limits of Infants' Early Word Learning

In this series of experiments, we tested the limits of young infants' word learning and generalization abilities in light of recent findings reporting sophisticated word learning abilities in the first year of life. Ten-month-old infants were trained with two word-object pairs and tested with either the same or different members of the corresponding categories. In Experiment 1, infants showed successful learning of the word-object associations, when trained and tested with a single exemplar from each category. In Experiment 2, infants were presented with multiple within-category items during training but failed to learn the word-object associations. In Experiment 3, infants were presented with a single exemplar from each category during training, and failed to generalize words to a new category exemplar. However, when infants were trained with items from perceptually and conceptually distinct categories in Experiment 4, they showed weak evidence for generalization of words to novel members of the corresponding categories. It is suggested that word learning in the first year begins as the formation of simple associations between words and objects that become enriched as experience with objects, words and categories accumulates across development.

Taking their eye off the ball: How shyness affects children's attention during word learning

The current study tests the hypothesis that shy children's reduced word learning is partly due to an effect of shyness on attention during object labeling. A sample of 20- and 26-month-old children (N = 32) took part in a looking-while-listening task in which they saw sets of familiar and novel objects while hearing familiar or novel labels. Overall, children increased attention to familiar objects when hearing their labels, and they divided their attention equally between the target and competitors when hearing novel labels. Critically, shyness reduced attention to the target object regardless of whether the heard label was novel or familiar. When children's retention of the novel word-object mappings was tested after a delay, it was found that children who showed increased attention to novel objects during labeling showed better retention. Taken together, these findings suggest that shyer children perform less well than their less shy peers on measures of word learning because their attention to the target object is dampened. Thus, this work presents evidence that shyness modulates the low-level processes of visual attention that unfold during word learning.

Beyond the Bayley: Neurocognitive Assessments of Development During Infancy and Toddlerhood

The use of global, standardized instruments is conventional among clinicians and researchers interested in assessing neurocognitive development. Exclusively relying on these tests for evaluating effects may underestimate or miss specific effects on early cognition. The goal of this review is to identify alternative measures for possible inclusion in future clinical trials and interventions evaluating early neurocognitive development. The domains included for consideration are attention, memory, executive function, language, and socioemotional development. Although domain-based tests are limited, as psychometric properties have not yet been well-established, this review includes tasks and paradigms that have been reliably used across various developmental psychology laboratories.

Auditory-visual misalignment: A theoretical perspective on vocabulary delays in children with ASD

In this commentary, we describe a novel theoretical perspective on vocabulary delays in children with autism spectrum disorder (ASD)-a perspective we refer to as auditory-visual misalignment. We synthesize empirical evidence that: (a) as a result of differences in both social and nonsocial visual attention, the auditory-visual statistics available to children with ASD for early word learning are misaligned; (b) this auditory-visual misalignment disrupts word learning and contributes to the vocabulary delays shown by children with ASD; and (c) adopting a perspective of auditory-visual misalignment has important theoretical and clinical implications for understanding and supporting vocabulary development in children with ASD. Theoretically, the auditory-visual misalignment perspective advances our understanding of how attentional differences impact vocabulary development in children with ASD in several ways. By adopting the point of view of the child, we provide a framework that brings together research on social and domain-general visual attention differences in children with ASD. In addition, the auditory-visual misalignment perspective moves current thinking beyond how misalignment disrupts vocabulary development in the moment, and considers the likely consequences of misalignment over developmental time. Finally, considering auditory-visual misalignment may assist in identifying active ingredients of existing language interventions or in developing new interventions that deliver high quality, aligned input. Future research is needed to determine how manipulating auditory-visual alignment changes word learning in ASD and whether the effects of auditory-visual misalignment are unique to ASD or shared with other neurodevelopmental disorders or sources of language impairment. Autism Research 2018, 11: 1621-1628. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This article describes a new way of thinking about vocabulary delays in children with autism spectrum disorder (ASD). We suggest that children with ASD may have difficulty learning words because their attention is not tuned in to what is most important for learning, creating a mismatch between what they see and what they hear. This perspective brings together research on different types of attentional differences in people with ASD. It may also help us to understand how language interventions work.

Cross-situational and ostensive word learning in children with and without autism spectrum disorder

Numerous experimental studies have shown that infants and children can discover word meanings by using co-occurrences between labels and objects across individually ambiguous contexts-a phenomenon known as cross-situational learning. Like typically developing children, high-functioning school aged children with autism spectrum disorder (ASD) are capable of cross-situational learning. However, it is not yet clear whether cross-situational learning is similarly available to children with ASD who are younger and show a broader range of language and cognitive abilities. Using eye-tracking methodology, the current study provided the first evidence that preschool and early school-aged children with ASD can rely on cross-situational statistics to learn new words. In fact, children with ASD learned as well as typically developing children with similar vocabulary knowledge. In both groups, the children with the highest cross-situational learning accuracy were those who showed the best familiar word processing skills. Surprisingly, children in both groups learned words equally well in the cross-situational task and an ostensive word-learning task, which presented only a single label-object pairing at a time. In combination, these results point to similarities in the word learning abilities available to typically developing children and children with ASD.

Symbolic flexibility during unsupervised word learning in children and adults

Considerable debate in language acquisition concerns whether word learning is driven by domain-general (symbolically flexible) or domain-specific learning mechanisms. Prior work has shown that very young children can map objects to either words or nonlinguistic sounds, but by 20 months of age this ability narrows to only words. This suggests that although symbolically flexible mechanisms are operative early, they become more specified over development. However, such research has been conducted only with young children in ostensive teaching contexts. Thus, we investigated symbolic flexibility at later ages in more referentially ambiguous learning situations. In Experiment 1, 47 6- to 8-year-olds acquired eight symbol-object mappings in a cross-situational word learning paradigm where multiple mappings are learned based only on co-occurrence. In the word condition participants learned with novel pseudowords, whereas in the sound condition participants learned with nonlinguistic sounds (e.g., beeps). Children acquired the mappings, but performance did not differ across conditions, suggesting broad symbolic flexibility. In Experiment 2, 41 adults learned 16 mappings in a comparable design. They learned with ease in both conditions but showed a significant advantage for words. Thus, symbolic flexibility decreases with age, potentially due to repeated experiences with linguistic materials. Moreover, trial-by-trial analyses of the microstructure of both children's and adults' performance did not reveal any substantial differences due to condition, consistent with the hypothesis that learning mechanisms are generally employed similarly with both words and nonlinguistic sounds.

Too Much of a Good Thing: How Novelty Biases and Vocabulary Influence Known and Novel Referent Selection in 18-Month-Old Children and Associative Learning Models

Identifying the referent of novel words is a complex process that young children do with relative ease. When given multiple objects along with a novel word, children select the most novel item, sometimes retaining the word-referent link. Prior work is inconsistent, however, on the role of object novelty. Two experiments examine 18-month-old children's performance on referent selection and retention with novel and known words. The results reveal a pervasive novelty bias on referent selection with both known and novel names and, across individual children, a negative correlation between attention to novelty and retention of new word-referent links. A computational model examines possible sources of the bias, suggesting novelty supports in-the-moment behavior but not retention. Together, results suggest that when lexical knowledge is weak, attention to novelty drives behavior, but alone does not sustain learning. Importantly, the results demonstrate that word learning may be driven, in part, by low-level perceptual processes.

All the Right Noises: Background Variability Helps Early Word Learning

Variability is prevalent in early language acquisition, but, whether it supports or hinders learning is unclear; while target variability has been shown to facilitate word learning, variability in competitor items has been shown to make the task harder. Here, we tested whether background variability could boost learning in a referent selection task. Two groups of 2-year-old children saw arrays of one novel and two known objects on a screen, and they heard a novel or known label. Stimuli were identical across conditions, with the exception that in the constant color condition objects appeared on a uniform white background, and in the variable color condition backgrounds were different, uniform colors. At test, only children in the variable condition showed evidence of retaining label-object associations. These data support findings from the adult memory literature, which suggest that variability supports learning by decontextualizing representations. We argue that these data are consistent with dynamic systems accounts of learning in which low-level entropy adds sufficient noise to the developmental system to precipitate a change in behavior.

Semantic richness and word learning in children with autism spectrum disorder

Semantically rich learning contexts facilitate semantic, phonological, and articulatory aspects of word learning in children with typical development (TD). However, because children with autism spectrum disorder (ASD) show differences at each of these processing levels, it is unclear whether they will benefit from semantic cues in the same manner as their typical peers. The goal of this study was to track how the inclusion of rich, sparse, or no semantic cues influences semantic, phonological, and articulatory aspects of word learning in children with ASD and TD over time. Twenty-four school-aged children (12 in each group), matched on expressive vocabulary, participated in an extended word learning paradigm. Performance on five measures of learning (referent identification, confrontation naming, defining, phonetic accuracy, and speech motor stability) were tracked across three sessions approximately one week apart to assess the influence of semantic richness on extended learning. Results indicate that children with ASD benefit from semantically rich learning contexts similarly to their peers with TD; however, one key difference between the two groups emerged - the children with ASD showed heightened shifts in speech motor stability. These findings offer insights into common learning mechanisms in children with ASD and TD, as well as pointing to a potentially distinct speech motor learning trajectory in children with ASD, providing a window into the emergence of stereotypic vocalizations in these children.

The effect of shyness on children's formation and retention of novel word-object mappings

This study set out to examine whether shyness, an aversion to novelty and unfamiliar social situations, can affect the processes that underlie early word learning. Twenty-four-month-old children (n =32) were presented with sets of one novel and two familiar objects, and it was found that shyer children were less likely to select a novel object as the referent of a novel label. Furthermore, not-shy children then showed evidence of retaining these novel mappings, but shy children did not. These findings suggest that shy children's aversion to novelty and to the unfamiliar context can impact on their word learning.

Assessing a continuum of lexical-semantic knowledge in the second year of life: A multimodal approach

Behavioral dissociations in young children's visual and haptic responses have been taken as evidence that word knowledge is not all-or-none but instead exists on a continuum from absence of knowledge, to partial knowledge, to robust knowledge. This longitudinal study tested a group of 16- to 18-month-olds, 6months after their initial visit, to replicate results of partial understanding as shown by visual-haptic dissociations and to determine whether partial knowledge of word-referent relations can be leveraged for future word recognition. Results show that, like 16-month-olds, 22-month-olds demonstrate behavioral dissociations exhibited by rapid visual reaction times to a named referent but incorrect haptic responses. Furthermore, results suggest that partial word knowledge at one time predicts the degree to which that word will be understood in the future.

Moving Word Learning to a Novel Space: A Dynamic Systems View of Referent Selection and Retention

Theories of cognitive development must address both the issue of how children bring their knowledge to bear on behavior in-the-moment, and how knowledge changes over time. We argue that seeking answers to these questions requires an appreciation of the dynamic nature of the developing system in its full, reciprocal complexity. We illustrate this dynamic complexity with results from two lines of research on early word learning. The first demonstrates how the child's active engagement with objects and people supports referent selection via memories for what objects were previously seen in a cued location. The second set of results highlights changes in the role of novelty and attentional processes in referent selection and retention as children's knowledge of words and objects grows. Together this work suggests that understanding systems for perception, action, attention, and memory, and their complex interaction, is critical to understand word learning. We review recent literature that highlights the complex interactions between these processes in cognitive development and point to critical issues for future work.

Early Verb-Action and Noun-Object Mapping Across Sensory Modalities: A Neuro-Developmental View

The authors provide an alternative to the traditional view that verbs are harder to learn than nouns by reviewing three lines of behavioral and neurophysiological evidence in word-mapping development across cultures. First, preverbal infants tune into word-action and word-object pairings using domain-general mechanisms. Second, while post-verbal infants from noun-friendly language environments experience verb-action mapping difficulty, infants from verb-friendly language environments do not. Third, children use language-specific conventions to learn all types of words, although still strongly influenced by their language environment. Additionally, the authors suggest neurophysiological research to advance these lines of evidence beyond traditional views of word learning.

What does it take to learn a word?

Vocabulary learning is deceptively hard, but toddlers often make it look easy. Prior theories proposed that children's rapid acquisition of words is based on language-specific knowledge and constraints. In contrast, more recent work converges on the view that word learning proceeds via domain-general processes that are tuned to richly structured-not impoverished-input. We argue that new theoretical insights, coupled with methodological tools, have pushed the field toward an appreciation of simple, content-free processes working together as a system to support the acquisition of words. We illustrate this by considering three central phenomena of early language development: referential ambiguity, fast-mapping, and the vocabulary spurt. WIREs Cogn Sci 2017, 8:e1421. doi: 10.1002/wcs.1421 For further resources related to this article, please visit the WIREs website.

Fourteen-month-olds' decontextualized understanding of words for absent objects

The majority of research examining infants' decontextualized word knowledge comes from studies in which words and pictures are presented simultaneously. However, comprehending utterances about unseen objects is a hallmark of language. Do infants demonstrate decontextualized absent object knowledge early in the second year of life? Further, to what extent do words evoke strictly prototypical representations of absent objects? To investigate these questions we analyzed 14-month-olds' comprehension of labels for absent entities without contextual support. In a novel, auditory-visual priming paradigm, infants heard passages containing two target words and then saw four animations - two that matched the meaning of the target words and two they had not heard in the passages. We found that by age 1;2, spoken words evoke prototypical representations of absent entities. Additionally, our findings demonstrate a promising new method for exploring absent object comprehension in infants.

Spoken word recognition in children with autism spectrum disorder: The role of visual disengagement

Deficits in visual disengagement are one of the earliest emerging differences in infants who are later diagnosed with autism spectrum disorder. Although researchers have speculated that deficits in visual disengagement could have negative effects on the development of children with autism spectrum disorder, we do not know which skills are disrupted or how this disruption takes place. As a first step in understanding this issue, this study investigated the relationship between visual disengagement and a critical skill in early language development: spoken word recognition. Participants were 18 children with autism spectrum disorder (aged 4-7 years). Consistent with our predictions, children with poorer visual disengagement were slower and less accurate to process familiar words; disengagement explained over half of the variance in spoken word recognition. Visual disengagement remained uniquely associated with spoken word recognition after accounting for children's vocabulary size and age. These findings align with a recently proposed developmental model in which poor visual disengagement decreases the speed and accuracy of real-time spoken word recognition in children with autism spectrum disorder-which, in turn, may negatively affect their language development.

Repetition across successive sentences facilitates young children's word learning

Young children who hear more child-directed speech (CDS) tend to have larger vocabularies later in childhood, but the specific characteristics of CDS underlying this link are currently underspecified. The present study sought to elucidate how the structure of language input boosts learning by investigating whether repetition of object labels in successive sentences-a common feature of natural CDS-promotes young children's efficiency in learning new words. Using a looking-while-listening paradigm, 2-year-old children were taught the names of novel objects, with exposures either repeated across successive sentences or distributed throughout labeling episodes. Results showed successful learning only when label-object pairs had been repeated in blocks of successive sentences, suggesting that immediate opportunities to detect recurring structure facilitate young children's learning. These findings offer insight into how the information flow within CDS might influence vocabulary development, and we consider the findings alongside research showing the benefits of distributing information across time. (PsycINFO Database Record