Word-object Associations Research Articles

Brief Report: Using Computer-Assisted Multiple Exemplar Instruction to Facilitate the Development of Bidirectional Naming for Children with Autism Spectrum Disorder.

Bidirectional naming is an important ability which enables children to acquire listener and speaker behaviors through exposure to relevant word-object associations. Many children with autism spectrum disorder (ASD) or developmental delays do not demonstrate this ability and require systematic instruction. The purpose of the present study was to evaluate the efficacy of computer-assisted multiple exemplar instruction to facilitate bidirectional naming. Three 5-year-old Chinese boys with ASD participated in a multiple probe across three participants design. The results indicated that all three children's naming performance increased from pretest to posttest, supporting the potential practicality of the instructional system for use in applied settings.

Word learning from a tablet app: Toddlers perform better in a passive context.

In recent years, the popularity of tablets has skyrocketed and there has been an explosive growth in apps designed for children. Howhever, many of these apps are released without tests for their effectiveness. This is worrying given that the factors influencing children's learning from touchscreen devices need to be examined in detail. In particular, it has been suggested that children learn less from passive video viewing relative to equivalent live interaction, which would have implications for learning from such digital tools. However, this so-called video deficit may be reduced by allowing children greater influence over their learning environment. Across two touchscreen-based experiments, we examined whether 2- to 4-year-olds benefit from actively choosing what to learn more about in a digital word learning task. We designed a tablet study in which "active" participants were allowed to choose which objects they were taught the label of, while yoked "passive" participants were presented with the objects chosen by their active peers. We then examined recognition of the learned associations across different tasks. In Experiment 1, children in the passive condition outperformed those in the active condition (n = 130). While Experiment 2 replicated these findings in a new group of Malay-speaking children (n = 32), there were no differences in children's learning or recognition of the novel word-object associations using a more implicit looking time measure. These results suggest that there may be performance costs associated with active tasks designed as in the current study, and at the very least, there may not always be systematic benefits associated with active learning in touchscreen-based word learning tasks. The current studies add to the evidence that educational apps need to be evaluated before release: While children might benefit from interactive apps under certain conditions, task design and requirements need to consider factors that may detract from successful performance.

Development of rapid word-object associations in relation to expressive vocabulary: Shared commonalities in infants and toddlers with and without Williams syndrome.

Associative word learning, i.e., associating a word with an object, is an important building block of early word learning for TD infants. This study investigated the development of word-object associations by TD infants and infants and toddlers with Williams syndrome (WS), a rare genetic disorder associated with delayed language and cognitive development. The specific reasons for the language delays remain unknown. We investigated whether their early language delay could be related to differences in how word-object associations are formed. Fifty-nine 11- to 14-month-old TD infants and thirty-one 12- to 35-month-olds with WS were tested on a modified version of the "switch" task (Werker, Cohen, Lloyd, Casasola, & Stager, 1998) using phonetically dissimilar words and novel objects. Infants were classified as word learners or novice word learners based on their expressive vocabularies (greater than 10 words vs. 10 words or fewer). We found similar developmental patterns across both populations: Expressive vocabulary size classification was an important index of the development of word-object associations. Moreover, the development of word-object associations evidenced a domain-general progression from independent (processing objects separately from words) to integrated (processing associations between words and objects). As a group, word learners formed word-object associations, but novice word learners did not; instead, they focused primarily on the objects. Findings build on previous research suggesting that although early language acquisition is delayed in infants with WS, infants and toddlers with and without WS share a common developmental pattern and set of mechanisms in early word learning.

Comparing cross-situational word learning, retention, and generalisation in children with autism and typical development

Word learning is complicated by referential ambiguity – there are often multiple potential targets for a newly-heard word. While typically developing (TD) children can accurately infer word meanings from cross-situational statistics, specific difficulties tracking word-object co-occurrences may contribute to language impairments in autism spectrum disorder (ASD). Here, we investigate cross-situational word learning as an integrated system including mapping, retention, and generalisation in both typical development and autism. In Study 1, children with ASD were as accurate at disambiguating the meanings of novel words from statistical correspondences as TD controls matched on receptive vocabulary. In Study 2, both populations spontaneously utilised social and non-social attentional cues to facilitate and accelerate their mapping of word-referent relationships. Across Studies 1 and 2, both groups retrieved and generalised word-referent representations with impressive and comparable accuracy. Although children with ASD performed very similarly to TD children on measures of learning accuracy, they were significantly slower to identify correct referents under both cued and non-cued learning conditions. These findings indicate that mechanisms supporting cross-situational word learning, and the relationships between them, are not qualitatively atypical in language-delayed children with ASD. However, the increased time required to generate correct responses suggests that these mechanisms may be less efficient, potentially impacting learning in natural environments where visual and auditory stimuli are presented rapidly. Our data support claims that word learning in the longer term is driven by the gradual accumulation of word-object associations over multiple learning instances and could potentially inform the development of interventions designed to scaffold word learning.

Communicative cues in the absence of a human interaction partner enhance 12-month-old infants’ word learning

Is infants’ word learning boosted by nonhuman social agents? An on-screen virtual agent taught infants word–object associations in a setup where the presence of contingent and referential cues could be manipulated using gaze contingency. In the study, 12-month-old Japanese-learning children (N = 36) looked significantly more to the correct object when it was labeled after exposure to a contingent and referential display versus a noncontingent and nonreferential display. These results show that communicative cues can augment learning even for a nonhuman agent, a finding highly relevant for our understanding of the mechanisms through which the social environment supports language acquisition and for research on the use of interactive screen media.

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

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

The Limits of Infants’ Early Word Learning

ABSTRACTIn 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.

Consistency of co-occurring actions influences young children's word learning.

Communication with young children is often multimodal in nature, involving, for example, language and actions. The simultaneous presentation of information from both domains may boost language learning by highlighting the connection between an object and a word, owing to temporal overlap in the presentation of multimodal input. However, the overlap is not merely temporal but can also covary in the extent to which particular actions co-occur with particular words and objects, e.g. carers typically produce a hopping action when talking about rabbits and a snapping action for crocodiles. The frequency with which actions and words co-occurs in the presence of the referents of these words may also impact young children’s word learning. We, therefore, examined the extent to which consistency in the co-occurrence of particular actions and words impacted children’s learning of novel word–object associations. Children (18 months, 30 months and 36–48 months) and adults were presented with two novel objects and heard their novel labels while different actions were performed on these objects, such that the particular actions and word–object pairings always co-occurred (Consistent group) or varied across trials (Inconsistent group). At test, participants saw both objects and heard one of the labels to examine whether participants recognized the target object upon hearing its label. Growth curve models revealed that 18-month-olds did not learn words for objects in either condition, and 30-month-old and 36- to 48-month-old children learned words for objects only in the Consistent condition, in contrast to adults who learned words for objects independent of the actions presented. Thus, consistency in the multimodal input influenced word learning in early childhood but not in adulthood. In terms of a dynamic systems account of word learning, our study shows how multimodal learning settings interact with the child’s perceptual abilities to shape the learning experience.

Associative word learning in infancy: A meta-analysis of the switch task.

Associative word learning, the ability to pair a concept to a word, is an essential mechanism for early language development. One common method by which researchers measure this ability is the Switch task (Werker, Cohen, Lloyd, Casasola, & Stager, 1998), wherein infants are habituated to 2 word-object pairings and then tested on their ability to notice a switch in those pairings. In this comprehensive meta-analysis, we summarized 141 Switch task studies involving 2,723 infants of 12 to 20 months to estimate an average effect size for the task (random-effect model) and to explore how key experimental factors affect infants' performance (fixed-effect model). The average effect size was low to moderate in size, Cohen's d = 0.32. The use of language-typical and dissimilar-sounding words as well as the presence of additional facilitative cues aided performance, particularly for younger infants. Infants learning 2 languages at home outperformed those learning 1, indicating a bilingual advantage in learning word-object associations. Together, these findings support the Processing Rich Information from Multidimensional Interactive Representations (PRIMIR) theoretical framework of infant speech perception and word learning (e.g., Werker & Curtin, 2005), but invite further theoretical work to account for the observed bilingual advantage. Lastly, some of our analyses raised the possibility of questionable research practices in this literature. Therefore, we conclude with suggestions (e.g., preregistration, transparent data peeking, and alternate statistical approaches) for how to address this important issue. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

An Optimal Oscillatory Phase for Pattern Reactivation during Memory Retrieval

Computational models and invivo studies in rodents suggest that the hippocampal system oscillates between states that are optimal for encoding and states that are optimal for retrieval. Here, we show that in humans, neural signatures of memory reactivation are modulated by the phase of a theta oscillation. Electroencephalography (EEG) was recorded while participants were cued to recall previously learned word-object associations, and time-resolved pattern classifiers were trained to detect neural reactivation of the target objects. Classifier fidelity rhythmically fluctuated at 7 or 8Hz and was modulated by theta phase across the entire recall period. The phase of optimal classification was shifted approximately 180° between encoding and retrieval. Inspired by animal work, we then computed "classifier-locked averages" to analyze how ongoing theta oscillations behaved around the time points at which the classifier indicated memory retrieval. We found strong theta (7 or 8Hz) phase consistency approximately 300ms before the time points of maximal neural memory reactivation. Our findings provide important evidence that the neural signatures of memory retrieval fluctuate and are time locked to the phase of an ongoing theta oscillation.

A visual auditory model based on Growing Self-Organizing Maps to analyze the taxonomic response in early childhood

In this paper we present an extension of a visual auditory neural network model previously proposed by Mayor and Plunkett (2010) in order to explain the emergence of the taxonomic response in early childhood. The original model consists of two self-organizing maps (respectively, visual and acoustic) connected with Hebbian connections. With respect to the original model, our proposal adds two major features. First, our model follows a dynamic training regime, learning categories and word-object associations that evolve through time. Second, the visual and acoustic maps are Growing self-organizing maps that grow during training, when they are no longer able to consistently represent categories. With these two new characterizing features, our model replicates the performance of the original Mayor and Plunkett (2010)’s model, acquires psychological plausibility in the training regime, and avoids the risk of catastrophic interference.

Differentiation of Human Medial Prefrontal Cortex Activity Underlies Long-Term Resistance to Forgetting in Memory.

It is well known that distributing study events over time leads to better memory over long time scales, compared with massing study events together. One explanation for such long-term resistance to forgetting is that distributed study leads to neural differentiation in memory, which supports retrieval of past experiences by disambiguating highly similar memory representations. Neuroanatomical models of episodic memory retrieval propose that the hippocampus and medial prefrontal cortex (MPFC) work together to enable retrieval of behaviorally appropriate memories. However, it is not known how representations in these regions jointly support resistance to forgetting long after initial learning. Using fMRI, we measured differentiation in retrieved memory representations following an extended delay in male and female human participants. After 1 week, word-object associations were better remembered if studied across 2 d (overnight), allowing associations to be learned in distinct temporal contexts, compared with learning within a single day (same day). MPFC retrieval patterns showed differentiation for overnight relative to same day memories, whereas hippocampal patterns reflected associative retrieval success. Overnight memory differentiation in MPFC was higher for associative than item memories and higher than differentiation assessed over a brain-wide set of retrieval-active voxels. The memory-related difference in MPFC pattern differentiation correlated with memory success for overnight learning and with hippocampal-MPFC functional connectivity. These results show that learning information across days leads to differentiated MPFC memory representations, reducing forgetting after 1 week, and suggest this arises from persistent interactions between MPFC and hippocampus.SIGNIFICANCE STATEMENT Neural activity in both the hippocampus and medial prefrontal cortex (MPFC) has been linked to memory-related representations, but prior work has not examined how these representations support episodic memory retrieval over extended time scales that are characteristic of everyday retrieval. We show that differentiation in MPFC activity 1 week after encoding is higher for retrieved information learned across 2 d compared with within a single day. In hippocampus, differentiation was greater for detailed memory retrieval but was not influenced by whether information had been learned over 1 or 2 d. Differentiation in MPFC predicted behavioral robustness to forgetting and was correlated with hippocampal-MPFC connectivity. The results suggest that context-based differentiation supports robust long-term memory via persistent MPFC-hippocampal interactions.

Napping and toddlers’ memory for fast-mapped words

When toddlers hear a novel word, they quickly and independently link it with a novel object rather than known-name objects. However, they are less proficient in retaining multiple novel words. Sleep and even short naps can enhance declarative memory in adults and children and this study investigates the effect of napping on children’s memory for novel words. Forty two-and-a-half-year-old children were presented with referent selection trials for four novel nouns. Children’s retention of the words was tested immediately after referent selection, four hours later in the afternoon, and the following morning. Half of the toddlers napped prior to the afternoon retention test. Amongst the toddlers who napped, retention scores remained steady four hours after exposure and the following morning. In contrast, for the wake group, there was a steady decline in retention scores by the following morning and significantly lower retention scores compared to the nap group. Napping following exposure to novel word–object associations could help in maintaining memories and limiting decay. Nap duration was also associated with better retention scores, but there were no effects of sleep quality, habitual napping, or sleepiness. The findings have implications for the role of napping in children’s language acquisition.

Mine, Mine, Mine: Self-Reference and Children's Retention of Novel Words.

Adults demonstrate enhanced memory for words encoded as belonging to themselves compared to those belonging to another. Known as the self-reference effect, there is evidence for the effect in children as young as three. Toddlers are efficient in linking novel words to novel objects, but have difficulties retaining multiple word-object associations. The aim here was to investigate the self-reference ownership paradigm on 3-year-old children’s retention of novel words. Following exposure to each of four novel word-object pairings, children were told that objects either belonged to them or another character. Children demonstrated significantly higher immediate retention of self-referenced compared to other-referenced items. Retention was also tested 4 h later and the following morning. Retention for self- and other-referenced words was significantly higher than chance at both delayed time points, but the difference between the self- and other-referenced words was no longer significant. The findings suggest that when it comes to toddlers’ retention of multiple novel words there is an initial memory enhancing effect for self- compared to other-referenced items, but the difference diminishes over time. Children’s looking times during the self-reference presentations were positively associated with retention of self-referenced words 4 h later. Looking times during the other-reference presentations were positively associated with proportional looking at other-referenced items during immediate retention testing. The findings have implications for children’s memory for novel words and future studies could test children’s explicit memories for the ownership manipulation itself and whether the effect is superior to other forms of memory supports such as ostensive naming.

Cross-Situational Learning Is Supported by Propose-but-Verify Hypothesis Testing

When we encounter a new word, there are often multiple objects that the word might refer to [1]. Nonetheless, because names for concrete nouns are constant, we are able to learn them across successive encounters [2, 3]. This form of "cross-situational" learning may result from either associative mechanisms that gradually accumulate evidence for each word-object association [4, 5] or rapid propose-but-verify (PbV) mechanisms where only one hypothesized referent is stored for each word, which is either subsequently verified or rejected [6, 7]. Using model-based representation similarity analyses of fMRI data acquired during learning, we find evidence for learning mediated by a PbV mechanism. This learning may be underpinned by rapid pattern-separation processes in the hippocampus. Our findings shed light on the psychological and neural processes that support word learning, suggesting that adults rely on their episodic memory to track a limited number of word-object associations.

Intentional inference during infants’ observational word learning

Word learning theories propose a dynamic development mechanism in which infants recruit statistical and perceptual cues at an earlier stage and social cues at a later stage, but it still remains unclear what promotes transition between the two stages. Recent studies have shown that the ostensive cue promotes infants’ social learning, de-emphasizing, and even denying, the contribution of their development of teleological cognition. The present study was operationalized to explore the influence of the bare teleological inference by teaching infants words in a monadic observational context where they were the only participants, and where no ostensive cues were provided by other agents. We utilized Woodward's (1998) experimental scheme and presented 12- and 17-month-old infants with a hand or a rod repeatedly approaching and grasping or touching a pair of objects, paired with two novel word labels respectively. In the test phase, where the position of objects was changed, two word–object associations were either switched or not. No detection of the changes was found for the non-intentional rod in both age groups. In contrast, with the intentional hand agent, the older group showed detection of the referential relation between word labels and objects, but the younger group simply showed sensitivity to the position. These findings provide an important insight into issues such as how infants used their teleological inference in word learning, and how multiple cues are integrated during the transition of infant word learning from statistic and perceptual learning to social and interactive learning.

Novel word acquisition in aphasia: Facing the word-referent ambiguity of natural language learning contexts

Recent research suggests that some people with aphasia preserve some ability to learn novel words and to retain them in the long-term. However, this novel word learning ability has been studied only in the context of single word-picture pairings. We examined the ability of people with chronic aphasia to learn novel words using a paradigm that presents new word forms together with a limited set of different possible visual referents and requires the identification of the correct word-object associations on the basis of online feedback. We also studied the relationship between word learning ability and aphasia severity, word processing abilities, and verbal short-term memory (STM). We further examined the influence of gross lesion location on new word learning. The word learning task was first validated with a group of forty-five young adults. Fourteen participants with chronic aphasia were administered the task and underwent tests of immediate and long-term recognition memory at 1 week. Their performance was compared to that of a group of fourteen matched controls using growth curve analysis. The learning curve and recognition performance of the aphasia group was significantly below the matched control group, although above-chance recognition performance and case-by-case analyses indicated that some participants with aphasia had learned the correct word-referent mappings. Verbal STM but not word processing abilities predicted word learning ability after controlling for aphasia severity. Importantly, participants with lesions in the left frontal cortex performed significantly worse than participants with lesions that spared the left frontal region both during word learning and on the recognition tests. Our findings indicate that some people with aphasia can preserve the ability to learn a small novel lexicon in an ambiguous word-referent context. This learning and recognition memory ability was associated with verbal STM capacity, aphasia severity and the integrity of the left inferior frontal region.

Brief Report: Fast Mapping Predicts Differences in Concurrent and Later Language Abilities Among Children with ASD.

This study investigated whether the ability to learn word-object associations following minimal exposure (i.e., fast mapping) was associated with concurrent and later language abilities in children with ASD. Children who were poor learners at age 3½ had significantly lower receptive language abilities than children who successfully learned the new words, both concurrently (n = 59) and 2 years later (n = 53), lending ecological validity to experimental fast-mapping tasks. Fast mapping comprehension at age 3½ was associated with better language outcomes regardless of whether children had produced the new words. These findings highlight the importance of investigating processes of language learning in children with ASD. Understanding these processes will enable the development of maximally effective strategies for supporting word learning.

Using Eye-Movement Trackings to Investigate Mechanisms of Word-Object Associations in Primary Progressive Aphasia (P2.165)

Using Eye-Movement Trackings to Investigate Mechanisms of Word-Object Associations in Primary Progressive Aphasia (P2.165)

Infants track word forms in early word-object associations

A central component of language development is word learning. One characterization of this process is that language learners discover objects and then look for word forms to associate with these objects (Mcnamara, 1984; Smith, 2000). Another possibility is that word forms themselves are also important, such that once learned, hearing a familiar word form will lead young word learners to look for an object to associate with it (Juscyzk, 1997). This research investigates the relative weighing of word forms and objects in early word-object associations using the anticipatory eye-movement paradigm (AEM; McMurray & Aslin, 2004). Eighteen-month-old infants and adults were taught novel word-object associations and then tested on ambiguous stimuli that pitted word forms and objects against each other. Results revealed a change in weighing of these components across development. For 18-month-old infants, word forms weighed more in early word-object associative learning, while for adults, objects were more salient. Our results suggest that infants preferentially use word forms to guide the process of word-object association.