Maternal naming of object wholes versus parts to preverbal infants: a fine-grained analysis of scaffolding at 6-8 months.

Maternal naming of object wholes versus parts was examined during interactive free-play. Forty-two Caucasian- and Hispanic-American mothers and their preverbal infants of 6-8 months were video-taped interacting naturally during toy play. For the purpose of fine-grained analyses, maternal naming of object wholes versus parts were coded for bimodal naming (e.g., temporal synchrony) and object motion (e.g., shaking) to examine any differences in these measures across the two word types. The results revealed that during naming, mothers simultaneously moved object wholes more often than they did object parts to highlight the object wholes in their infants' visual field. To further highlight object wholes during naming, mothers predominantly shook or loomed object wholes in synchrony with their naming more often than object parts. These empirical findings suggest that very early during infants' word-mapping development, maternal scaffolding is manifold and assists in infants' disambiguation of names for object wholes versus parts.

Invariance detection within an interactive system: a perceptual gateway to language 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.

Learning of syllable-object relations by preverbal infants: the role of temporal synchrony and syllable distinctiveness.

The role of temporal synchrony and syllable distinctiveness in preverbal 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 8months of age and distinct syllables at 7months of age. These findings suggest an interaction between infants' synchrony and syllable distinctiveness perception during early word mapping development.

Two-month-old infants' sensitivity to changes in arbitrary syllable-object pairings: the role of temporal synchrony.

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 asynchronous 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.

Type of Maternal Object Motion During Synchronous Naming Predicts Preverbal Infants' Learning of Word-Object Relations.

Mothers' use of specific types of object motion in synchrony with object naming was examined, along with infants' joint attention to the mother and object, as a predictor of word learning. During a semistructured 3-min play episode, mothers (N = 24) taught the names of 2 toy objects to their preverbal 6- to 8-month-old infants. The episodes were recoded from Gogate, Bolzani, and Betancourt (2006) to provide a more fine-grained description of object motions used by mothers during naming. The results indicated that mothers used forward/downward and shaking motions more frequently and upward and backward motions less frequently in temporal synchrony with the spoken words. These motions likely highlight novel word-object relations. Furthermore, maternal use of shaking motions in synchrony with the spoken words and infants' ability to switch gaze from mother to object contributed to infants' learning of the word-object relations, as observed on a posttest. Thus, preverbal infants' learn word-object relations within an embodied system involving tightly coupled interaction between infants' perception and joint attention, and specific properties of caregivers' naming.

Attention to Maternal Multimodal Naming by 6- to 8-Month-Old Infants and Learning of Word-Object Relations.

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.

Attention and memory for faces and actions in infancy: the salience of actions over faces in dynamic events.

Discrimination and memory for video films of women performing different activities was investigated in 5.5 month-old infants. In Experiment 1, infants (N = 24) were familiarized to the faces of one of three women performing one of three repetitive activities (blowing bubbles, brushing hair, and brushing teeth). Overall, results indicated discrimination and memory for the actions but not the faces after both a 1-min and a 7-week delay. Memory was demonstrated by a visual preference for the novel actions after the 1-min delay and for the familiar actions after the 7-week delay, replicating prior findings that preferences shift as a function of retention time. Experiment 2 (N = 12) demonstrated discrimination and memory for the faces when infants were presented in static poses at the 1-min delay, but not the 7-week delay. In Experiment 3 (N = 18), discrimination of the actions was replicated, but no discrimination among the objects embedded in the actions (hairbrush, bubble wand, toothbrush) was found. These findings demonstrate the attentional salience of actions over faces in dynamic events to 5.5 month-olds. They highlight the disparity between results generated from moving versus static displays in infancy research and emphasize the importance of using dynamic events as a basis for generalizing about perception and memory for events in the real world.

Don't preverbal infants map words onto referents?

Bloom provides a detailed account of children's word learning and comprehension. Yet, this book falls short of explaining the developmental process of word learning. The studies reviewed do not explain how infants begin to map words onto objects or the environment's facilitative role. Researchers must describe how several factors interact and explain the relative importance of each during the development of word learning.