Lakshmi Gogate

Background: Term infants learn word-object relations in their first year during multisensory interactions with caregivers. Although preterm infants often experience language delays, little is known about how caregivers contribute to their early word-object learning. The present longitudinal study compared maternal naming and word learning in these infant-groups.
Methods: Forty moderately preterm and forty term infants participated at 6-9 and 12 months with their mothers. At each visit, mothers named two novel objects during play, and infants’ learning was assessed using dynamic displays of the familiar and novel (mismatched) word-object relations. Infants’ general cognitive, language, and motoric abilities were evaluated. Maternal multisensory naming was coded for synchrony between the target words and object motions and other naming styles.
Results: During play, although overall maternal naming-style was similar across infant-groups within visits, naming frequency increased to term but not preterm infants, from visit 1 to 2. On the test at visit 1, although the term infants’ looked equally to novel and familiar word-object relations, their looking to the novel relations correlated positively with maternal synchrony use but inversely with naming frequency. At visit 2, term infants looked longer to the novel relations. In contrast, preterm infants showed no looking preference at either visit. Neither was their word-object learning correlated with maternal naming. Their cognition, language, and motor scores were attenuated compared to term infants on the Bayley-III but not their MCDI vocabulary.
Conclusions: Less adaptive maternal naming and delayed word-mapping in moderately preterm infants underscore a critical need for multisensory-language intervention prior to first-word onset to alleviate its cascading effects on later language.

This experimental study examined bilingual (English and another noun-dominant language) and monolingual (English) preverbal (10.5-month-old) and postverbal (12.5-month-old) infants' word-action mapping. Sixteen infants in each group were habituated to dynamic video-displays of novel word-action pairings during infant-controlled habituation. They received two words, /wem/ and /baef/, spoken synchronously with an adult shaking or looming an object, and were tested with switched versus same word-action pairings. Results revealed that for the preverbal bilingual infants, word-action mapping is intensified relative to postverbal bilingual infants. For the postverbal bilingual infants, word-action mapping is attenuated and inversely correlated with noun learning. No such differences were observed in the monolingual infants. These findings illustrate a perceptual protraction prior to word production and accelerated perceptual narrowing to nouns after word production in bilingual infants learning two noun-dominant languages.

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.

This study investigated 7-month-old infants' ability to relate vowel sounds with objects when intersensory redundancy was present versus absent. Infants (N = 48) were habitu-ated to two alternating video-films of vowel-object pairs in one of three conditions. In the moving-synchronous condition, where redundancy was present, the movement of one object was temporally coordinated with the spoken vowel Ial and that of the other with Ii!, simulating showing and naming the objects to the infant. In the still and in the moving-asynchronous conditions, where redundancy was absent, infants saw static objects, and objects moving out of synchrony with the vowel sounds, respectively. The results indicated that infants detected a mismatch in the vowel-object pairs in the moving-synchronous condition but not in the still or the moving-asynchronous condition. These findings demonstrate that temporal synchrony between vocalizations and the motions of an object facilitates learning of arbitrary speech-object relations, an important precursor to the development of lexical comprehension in infancy. Adults refer to objects and actions by labeling them with conventionally used words. Words (concrete nouns and verbs) and their referents are arbitrarily .

To explore early lexical development, the authors examined infants' sensitivity to changes in spoken syllables and objects given different temporal relations between syllable– object pairings. In Experiment 1, they habituated 2-month-olds to 1 syllable, /tah/ or /gah/, paired with an object in synchronous (utterances coincident with object motions, N 16) or asynchronous (utterances erratic relative to object motions, N 16) conditions. In the asynchronous condition, the audio track preceded or succeeded the visual track by 1,200 ms. On test, infants in the synchronous condition alone detected the changes. Post hoc computational analyses confirmed lower time separation, interpreted as greater synchrony, between peaks and onsets– offsets of visual motion and audio energy in the synchronous relative to the asyn-chronous condition. Further examining lexical development, in Experiment 2 they habituated 2-month-olds (N 16) to two synchronous syllable– object pairs and tested them on switch versus same pairings. Infants failed to detect the switch in the pairings. These results suggest that 2-month-olds use synchrony to detect changes in one novel syllable– object pairing at a time, providing a basis for further word mapping development. Keywords: word mapping, auditory–visual perception, computational analysis of temporal synchrony, lexical development, language development

We examined whether mothers' use of temporal synchrony between spoken words and moving objects, and infants' attention to object naming, predict infants' learning of word–object relations. Following 5 min of free play, 24 mothers taught their 6-to 8-month-olds the names of 2 toy objects, Gow and Chi, during a 3-min play episode. Infants were then tested for their word mapping. The videotaped episodes were coded for mothers' object naming and infants' attention to different naming types. Results indicated that mothers' use of temporal synchrony and infants' attention during play covaried with infants' word-mapping ability. Specifically, infants who switched eye gaze from mother to object most frequently during naming learned the word–object relations. The findings suggest that maternal naming and infants' word-mapping abilities are bidirectionally related. Variability in infants' attention to maternal multimodal naming explains the variability in early lexical-mapping development.

This study examined European American and Hispanic American mothers' multimodal communication to their infants (N 24). The infants were from three age groups representing three levels of lexical-mapping development: prelexical (5 to 8 months), early-lexical (9 to 17 months), and advanced-lexical (21 to 30 months). Mothers taught their infants four target (novel) words by using distinct objects during a semistructured play episode. Recent research suggests that young infants rely on temporal synchrony to learn syllable–object relations , but later, the role of synchrony diminishes. Thus, mothers' target and nontarget naming were coded for synchrony and other communication styles. The results indicated that mothers used target words more often than nontarget words in synchrony with object motion and sometimes touch. Thus, " multimodal motherese " likely highlights target word-referent relations for infants. Further, mothers tailored their communication to in-fants' level of lexical-mapping development. Mothers of prelexical infants used target words in synchrony with object motion more often than mothers of early-and advanced-lexical infants. Mothers' decreasing use of synchrony across age parallels infants' decreasing reliance on synchrony, suggesting a dynamical and reciprocal environment–organismic relation.

The role of temporal synchrony and syllable distinctiveness in pre-verbal infants' learning of word–object relations was investigated. In Experiment 1, 7-and 8-month-olds (N = 64) were habituated under conditions where two similar-sounding syllables, /tah/ and /gah/, were spoken simultaneously with the motions of one of two sets of objects (synchronous) or out of phase with the motions (asynchronous). On test trials, 8-month-olds, but not 7-month-olds, showed learning of the relations in the synchronous condition but not in the asynchronous condition. Furthermore, in Experiment 2, following habituation to one of the synchronous syllable–object pairs, 7-month-olds (n = 8) discriminated the syllables and the objects. In Experiment 3, following habituation to two distinct syllables, /tah/–/gih/ or /gah/–/tih/, paired with identical objects, 7-month-olds (n = 40) showed learning of the relations, again only in the synchronous condition. Thus, synchrony, which mothers naturally provide between words and object motions, facilitated the mapping onto objects of similar-sounding syllables at 8 months of age and distinct syllables at 7 months of age. These findings suggest an interaction between infants' synchrony and syllable distinctive-ness perception during early word mapping development.

In this article, we hypothesize that invariance detection, a general perceptual phenomenon whereby organisms attend to relatively stable patterns or regularities, is an important means by which infants tune in to various aspects of spoken language. In so doing, we synthesize a substantial body of research on detection of regularities across the domains of speech perception, word segmentation, word–referent mapping, and grammar learning. In addition, we outline our framework for how invariance detection might serve as a perceptual gateway to more sophisticated communication by providing a foundation for subsequent emergent capacities. We test our hypothesis using the domain of word mapping as a case in point, emphasizing its epigenetic nature: Word mapping is rooted in the real-time interactions between the infant and the physical world. The present account offers an alternative to prior theories of early language development and helps to link the field of early language development with more general perceptual processes. Cognitive economy makes sense, and discovery of invariance is the essence of economy, finding order in change. (E. J. Gibson, 1991, p. 354) To learn a language, infants must discover how sounds (pho-nemes) combine to form meaningful units (morphemes); how those morphemes map onto objects, actions, and events in the real world (semantics); and how words combine to form new meanings (grammar). Our central hypothesis is that perceiving relatively stable regularities or consistencies, called invariance detection, is the fundamental starting point for infants to tune in to their ambient communication systems at these component levels: pho-netic, morphemic, semantic, and grammatical. In essence, by discovering contextually consistent patterns in caregivers' communication , infants develop the foundation to progress to successively more sophisticated levels of communication. Because of the epi-genetic nature of this process, the invariants detected (and offered by caregivers) will necessarily change over time. Our main goal is to provide a framework that suggests that invariance detection by the infant during ongoing real-time interactions between the infant and the physical world provides a perceptual gateway to language development. This framework offers a perceptual solution to problems that have preoccupied researchers concerned with the origins of language and its development—psychologists, philosophers, linguists, speech scientists, anthropologists, cognitive scientists, and neuroscientists. The mechanism of invariance detection has traditionally been used in perception to describe phonetic feature detection (Jakobson & Halle, 1956) or increasing differentiation (e.g., perception of different types of wines; J. J. Gibson & Gibson, 1955). However, given the importance of invariance detection as a mechanism for perception, we see no reason why it cannot explain the perceptual beginnings of language, even those aspects that are traditionally considered to be the domain of complex cognition, including rule learning and word mapping. Like E. J. Gibson (1966), by invari-ance detection we mean selective attention to relatively stable patterns or structural regularities in the changing stimulus array. This is in contrast to the colloquial definition of invariance, which links the term to stimuli that do not change or that remain constant. Invariant patterns are thus not always obvious in the changing stimulus array, nor do they occur 100% of the time. Nonetheless, as long as these patterns are consistent within a context, they can be detected and used by the child. Invariants are detected at multiple levels and times. Some stimuli that are perceived as random at first may in fact have a comparatively stable pattern that can be discovered with experience (e.g., reading an ultrasound). Likewise, invariance detection at a more basic level serves as a building block for invariance detection at more complex levels as language development progresses. Our broad definition accommodates all types of regularity detection—from the detection of perceptual invariants to more abstract invariants. Although this phenomenon has many specific names within each domain (e.g., phonological perception, normalization, categorization, generalization , statistical learning, and rule learning), the idea that infants come to detect commonalities seems relatively incontrovertible.

A wealth of research on child language has unearthed many novel strategies that parents and interventionists can utilize to enhance word learning prior to infants producing their first words. These developmentally-appropriate strategies are published in scientific journals, rendering them largely inaccessible to parents and non-research professionals. This volume presents research findings and practices in an accessible, user-friendly, manner.

A sizeable percentage of children entering first grade each year show vocabulary delays. Yet, best practices for enhancing vocabulary focus on children after they talk or exhibit delays.  By addressing what it takes to learn words from the start, this volume informs best practices for building vocabulary from the ground up to prevent delays. Chapters One-Six enumerate multiple strategies that primary caregivers naturally exhibit during interaction, and strategies isolated from experimental studies. Chapter Seven highlights the word learning of bilingual versus monolingual children. Finally, Chapter Eight addresses cultural variations and draws general conclusions across chapters.

The process of learning words and languages may seem like an instinctual trait, inherent to nearly all humans from a young age. However, a vast range of complex research and information exists in detailing the complexities of the process of word learning.

Theoretical and Computational Models of Word Learning: Trends in Psychology and Artificial Intelligence strives to combine cross-disciplinary research into one comprehensive volume to help readers gain a fuller understanding of the developmental processes and influences that makeup the progression of word learning. Blending together developmental psychology and artificial intelligence, this publication is intended for researchers, practitioners, and educators who are interested in language learning and its development as well as computational models formed from these specific areas of research.

Infants learn to communicate through everyday social interaction with their caregivers in a multisensory world involving sight, hearing, touch and smell. The neural and behavioural underpinnings of caregiver-infant multisensory interaction and communication, however, have remained largely unexplored in research across disciplines. This book highlights this largely uncharted territory to better understand the developmental origins of human multisensory perception and communication. It emphasizes the range and complexity of multisensory infant-caregiver interaction in the real world, and its developmental and neurophysiological characteristics. Furthermore, recent theories of brain development suggest that brain, body and the environment interact with one another on an ongoing basis, influencing each other and are constantly being influenced by each other. This volume aims to elucidate the neurophysiological, behavioural and environmental factors to better understand the nature of multisensory communication as a whole.