Comparing apples to manzanas and oranges to naranjas: A new measure of English-Spanish vocabulary for dual language learners.

The valid assessment of vocabulary development in dual-language-learning infants is critical to developmental science. We developed the Dual Language Learners English-Spanish (DLL-ES) Inventories to measure vocabularies of U.S. English-Spanish DLLs. The inventories provide translation equivalents for all Spanish and English items on Communicative Development Inventory (CDI) short forms; extended inventories based on CDI long forms; and Spanish language-variety options. Item-Response Theory analyses applied to Wordbank and Web-CDI data (n = 2603, 12-18 months; n = 6722, 16-36 months; half female; 1% Asian, 3% Black, 2% Hispanic, 30% White, 64% unknown) showed near-perfect associations between DLL-ES and CDI long-form scores. Interviews with 10 Hispanic mothers of 18- to 24-month-olds (2 White, 1 Black, 7 multi-racial; 6 female) provide a proof of concept for the value of the DLL-ES for assessing the vocabularies of DLLs.

Children's use of comparison and function in novel object categorization.

Although young children often rely on salient perceptual cues, such as shape, when categorizing novel objects, children eventually shift towards deeper relational reasoning about category membership. This study investigates what information young children use to classify novel instances of familiar categories. Specifically, we investigated two sources of information that have the potential to facilitate the classification of novel exemplars: (1) comparison of familiar category instances, and (2) attention to function information that might direct children's attention to functionally relevant perceptual features. Across two experiments, we found that comparing two perceptually similar category members-particularly when function information was also highlighted-led children to discover non-obvious relational features that supported their categorization of novel category instances. Together, these findings demonstrate that comparison may aid in novel object categorization by heightening the salience of less obvious, yet functionally relevant, relational structures that support conceptual reasoning.

Developmental change in children's sensitivity to sound symbolism.

The current study examined developmental change in children's sensitivity to sound symbolism. Three-, five-, and seven-year-old children heard sound symbolic novel words and foreign words meaning round and pointy and chose which of two pictures (one round and one pointy) best corresponded to each word they heard. Task performance varied as a function of both word type and age group such that accuracy was greater for novel words than for foreign words, and task performance increased with age for both word types. For novel words, children in all age groups reliably chose the correct corresponding picture. For foreign words, 3-year-olds showed chance performance, whereas 5- and 7-year-olds showed reliably above-chance performance. Results suggest increased sensitivity to sound symbolic cues with development and imply that although sensitivity to sound symbolism may be available early and facilitate children's word-referent mappings, sensitivity to subtler sound symbolic cues requires greater language experience.

Infants learn baby signs from video.

There is little evidence that infants learn from infant-oriented educational videos and television programming. This 4-week longitudinal experiment investigated 15-month-olds' (N = 92) ability to learn American Sign Language signs (e.g., patting head for hat) from at-home viewing of instructional video, either with or without parent support, compared to traditional parent instruction and a no-exposure control condition. Forced-choice, elicited production, and parent report measures indicate learning across all three exposure conditions, with a trend toward more robust learning in the parent support conditions, regardless of medium. There were no differences between experimental and control conditions in the acquisition of corresponding verbal labels. This constitutes the first experimental evidence of infants' ability to learn expressive communication from commercially available educational videos.

Cross-situational statistical word learning in young children.

Recent empirical work has highlighted the potential role of cross-situational statistical word learning in children's early vocabulary development. In the current study, we tested 5- to 7-year-old children's cross-situational learning by presenting children with a series of ambiguous naming events containing multiple words and multiple referents. Children rapidly learned word-to-object mappings by attending to the co-occurrence regularities across these ambiguous naming events. The current study begins to address the mechanisms underlying children's learning by demonstrating that the diversity of learning contexts affects performance. The implications of the current findings for the role of cross-situational word learning at different points in development are discussed along with the methodological implications of employing school-aged children to test hypotheses regarding the mechanisms supporting early word learning.

Young word learners' interpretations of words and symbolic gestures within the context of ambiguous reference.

Early in development, many word-learning phenomena generalize to symbolic gestures. The current study explored whether children avoid lexical overlap in the gestural modality, as they do in the verbal modality, within the context of ambiguous reference. Eighteen-month-olds' interpretations of words and symbolic gestures in a symbol-disambiguation task (Experiment 1) and a symbol-learning task (Experiment 2) were investigated. In Experiment 1 (N = 32), children avoided verbal lexical overlap, mapping novel words to unnamed objects; children failed to display this pattern with symbolic gestures. In Experiment 2 (N = 32), 18-month-olds mapped both novel words and novel symbolic gestures onto their referents. Implications of these findings for the specialized nature of word learning and the development of lexical overlap avoidance are discussed.

Say it like you mean it: mothers' use of prosody to convey word meaning.

Prosody plays a variety of roles in infants' communicative development, aiding in attention modulation, speech segmentation, and syntax acquisition. This study investigates the extent to which parents also spontaneously modulate prosodic aspects of infant directed speech in ways that distinguish semantic aspects of language. Fourteen mothers of two-year-old children read a picture book to their children in which they labeled pictures using dimensional adjectives (e.g., big, small, hot, cold). Recordings of the mothers' input to their children were analyzed acoustically and antonyms within each dimension were compared. Mothers modulated aspects of their prosody including amplitude and duration of target words and sentences to distinguish dimensional adjectives. Mothers appear to recruit prosody in the service of word learning.

The developing role of prosody in novel word interpretation.

This study examined whether children use prosodic correlates to word meaning when interpreting novel words. For example, do children infer that a word spoken in a deep, slow, loud voice refers to something larger than a word spoken in a high, fast, quiet voice? Participants were 4- and 5-year-olds who viewed picture pairs that varied along a single dimension (e.g., big vs. small flower) and heard a recorded voice asking them, for example, "Can you get the blicket one?" spoken with either meaningful or neutral prosody. The 4-year-olds failed to map prosodic cues to their corresponding meaning, whereas the 5-year-olds succeeded (Experiment 1). However, 4-year-olds successfully mapped prosodic cues to word meaning following a training phase that reinforced children's attention to prosodic information (Experiment 2). These studies constitute the first empirical demonstration that young children are able to use prosody-to-meaning correlates as a cue to novel word interpretation.

The differing roles of comparison and contrast in children's categorization.

Comparison of perceptually similar exemplars from an object category encourages children to overlook compelling perceptual similarities and use relational and functional properties more relevant for taxonomic categorization. This article investigates whether showing children a contrasting object that is perceptually similar but out of kind serves the same function as comparison in heightening children's attention to taxonomically relevant features. In this study, 4-year-olds completed a forced-choice categorization task in which they viewed exemplars from a target category and then selected among (a) a perceptually similar out-of-kind object, (b) a category member that differed perceptually from the exemplars, and (c) a thematically related object. Children were assigned to one of four conditions: No-Compare/No-Contrast, Compare/No-Contrast, No-Compare/Contrast, or Compare/Contrast. As in previous work, comparison increased the frequency of category responses, but there was no effect of contrast on categorization. However, only those in the Compare/Contrast condition displayed consistently taxonomic patterns of responding. Follow-up studies revealed that the effect of comparison plus contrast was evident only when comparison preceded, rather than followed, contrast information and that the value added by providing contrastive information is not attributable to the perceptual similarity between the category exemplars and the contrast object. Comparison and contrast make differing contributions to children's categorization.

The role of comparison in preschoolers' novel object categorization.

We examined the role of the comparison process and shared names on preschoolers' categorization of novel objects. In our studies, 4-year-olds were presented with novel object sets consisting of either one or two standards and two test objects: a shape match and a texture match. When children were presented with one standard, they extended the category based on shape regardless of whether the objects were named. When children were presented with two standards that shared the same texture and the objects were named with the same noun, they extended the category based on texture. The opportunity to compare two standards, in the absence of shared names, led to an attenuation of the effect of shape. These findings demonstrate that comparison plays a critical role in the categorization of novel objects and that shared names enhance this process.

The semantics of prosody: acoustic and perceptual evidence of prosodic correlates to word meaning.

This investigation examined whether speakers produce reliable prosodic correlates to meaning across semantic domains and whether listeners use these cues to derive word meaning from novel words. Speakers were asked to produce phrases in infant-directed speech in which novel words were used to convey one of two meanings from a set of antonym pairs (e.g., big/small). Acoustic analyses revealed that some acoustic features were correlated with overall valence of the meaning. However, each word meaning also displayed a unique acoustic signature, and semantically related meanings elicited similar acoustic profiles. In two perceptual tests, listeners either attempted to identify the novel words with a matching meaning dimension (picture pair) or with mismatched meaning dimensions. Listeners inferred the meaning of the novel words significantly more often when prosody matched the word meaning choices than when prosody mismatched. These findings suggest that speech contains reliable prosodic markers to word meaning and that listeners use these prosodic cues to differentiate meanings. That prosody is semantic suggests a reconceptualization of traditional distinctions between linguistic and nonlinguistic properties of spoken language.

Communicative Context Affects Use of Referential Prosody.

The current study assessed the extent to which the use of referential prosody varies with communicative demand. Speaker-listener dyads completed a referential communication task during which speakers attempted to indicate one of two color swatches (one bright, one dark) to listeners. Speakers' bright sentences were reliably higher pitched than dark sentences for ambiguous (e.g., bright red versus dark red) but not unambiguous (e.g., bright red versus dark purple) trials, suggesting that speakers produced meaningful acoustic cues to brightness when the accompanying linguistic content was underspecified (e.g., "Can you get the red one?"). Listening partners reliably chose the correct corresponding swatch for ambiguous trials when lexical information was insufficient to identify the target, suggesting that listeners recruited prosody to resolve lexical ambiguity. Prosody can thus be conceptualized as a type of vocal gesture that can be recruited to resolve referential ambiguity when there is communicative demand to do so.

Recognition of iconicity doesn't come for free.

Iconicity--resemblance between a symbol and its referent--has long been presumed to facilitate symbolic insight and symbol use in infancy. These two experiments test children's ability to recognize iconic gestures at ages 14 through 26 months. The results indicate a clear ability to recognize how a gesture resembles its referent by 26 months, but little evidence of recognition of iconicity at the onset of symbolic development. These findings imply that iconicity is not available as an aid at the onset of symbolic development but rather that the ability to apprehend the relation between a symbol and its referent develops over the course of the second year.

Eye movements reveal persistent sensitivity to sound symbolism during word learning.

Although the relationship between sound and meaning in language is assumed to be largely arbitrary, reliable correspondences between sound and meaning in natural language appear to facilitate word learning. Using a set of independently normed pseudoword and shape stimuli, we examined the real-time effects of sound-to-shape correspondences at initial presentation and throughout an extended learning process resulting in high accuracy. In addition to accuracy and response time (RT) measures, we monitored participants' eye movements to investigate the extent to which visual orienting to objects is influenced by the sound symbolic characteristics of novel labels at initial exposure and throughout learning. Over the course of word learning, congruency of sound and shape properties affected both accuracy and RT with higher accuracy and faster responses for congruent than incongruent items. Eye tracking data reveal that congruent targets were fixated faster than incongruent targets throughout learning and that nontargets consistent with the sound symbolic properties of the word remained attractive distracters, even after overt behavioral differences in accuracy disappeared. This demonstrates the sustained influence of sound symbolism and the importance of sensitive, continuous measures of assessing sound symbolic effects in word learning and lexical processing. Arbitrariness resulted in better final individuation performance only when the arbitrary items were more phonologically distinct than the sound symbolic stimuli. These findings suggest that the advantages of sound symbolism may persist beyond early word learning and serve to significantly influence online lexical processing. (PsycINFO Database Record

Developmental changes in neural activity to familiar words and gestures.

Infants younger than 20 months of age interpret both words and symbolic gestures as object names. Later in development words and gestures take on divergent communicative functions. Here, we examined patterns of brain activity to words and gestures in typically developing infants at 18 and 26 months of age. Event-related potentials (ERPs) were recorded during a match/mismatch task. At 18 months, an N400 mismatch effect was observed for pictures preceded by both words and gestures. At 26 months the N400 effect was limited to words. The results provide the first neurobiological evidence showing developmental changes in semantic processing of gestures.

The Specificity of Sound Symbolic Correspondences in Spoken Language.

Although language has long been regarded as a primarily arbitrary system, sound symbolism, or non-arbitrary correspondences between the sound of a word and its meaning, also exists in natural language. Previous research suggests that listeners are sensitive to sound symbolism. However, little is known about the specificity of these mappings. This study investigated whether sound symbolic properties correspond to specific meanings, or whether these properties generalize across semantic dimensions. In three experiments, native English-speaking adults heard sound symbolic foreign words for dimensional adjective pairs (big/small, round/pointy, fast/slow, moving/still) and for each foreign word, selected a translation among English antonyms that either matched or mismatched with the correct meaning dimension. Listeners agreed more reliably on the English translation for matched relative to mismatched dimensions, though reliable cross-dimensional mappings did occur. These findings suggest that although sound symbolic properties generalize to meanings that may share overlapping semantic features, sound symbolic mappings offer semantic specificity.

Making a silk purse out of two sow's ears: young children's use of comparison in category learning.

Comparison mechanisms have been implicated in the development of abstract, relational thought, including object categorization. D. Gentner and L. L. Namy (1999) found that comparing 2 perceptually similar category members yielded taxonomic categorization, whereas viewing a single member of the target category elicited shallower perceptual responding. The present experiments tested 2 predictions that follow from Gentner and Namy's (1999) model: (a) Comparison facilitates categorization only when the targets to be compared share relational commonalities, and (b) providing common labels for targets invites comparison, whereas providing conflicting labels deters it. Four-year-olds participated in a forced-choice task. They viewed 2 perceptually similar target objects and were asked to "find another one." Results suggest an important role for comparison in lexical and conceptual development.

Categorization and Its Developmental Relation to Early Language.

Three studies examine the developmental relation between early linguistic and cognitive achievements. Studies 1 and 2 attempt to replicate previous findings of a strong temporal link between the ages at there is a sharp rise in new nominal productions and the appearance of 2-category grouping using a longitudinal design. Studies 1 and 2 differ principally in whether the same stimuli were employed each time the children's categorization was tested or whether different stimuli were employed. Study 3 compares the categorization performance of children identified as late talkers to age-matched and language-matched controls cross-sectionally. Our findings consistently show that children's ability to classify objects in a spatial of temporal order is independent of advances in productive vocabulary growth. These results suggest that although children's developing knowledge of object categories may underlie developments in categorization and naming such developments depend on other abilities as well Studyin the past experiences of the child and the particular context in which the behavior is exhibited may be a more meaningful approach to understanding changes in categorization and ultimately its relation to language.

What's in a Name When It Isn't a Word? 17-Month-Olds' Mapping of Nonverbal Symbols to Object Categories.

Infants begin acquiring object labels as early as 12 months of age. Recent research has indicated that the ability to acquire object names extends beyond verbal labels to other symbolic forms, such as gestures. This experiment examines the latitude of infants' early naming abilities. We tested 17-month-olds' ability to map gestures, nonverbal sounds, and pictograms to object categories using a forced-choice triad task. Results indicated that infants accept a wide range of symbolic forms as object names when they are embedded in familiar referential naming routines. These data suggest that infants may initially have no priority for words over other symbolic forms as object names, although the relative status of words appears to change with development. The implications of these findings for the development of criteria for determining whether a symbol constitutes an object name early in development are considered.

Cross-linguistic sound symbolism and crossmodal correspondence: Evidence from fMRI and DTI.

Non-arbitrary correspondences between spoken words and categories of meanings exist in natural language, with mounting evidence that listeners are sensitive to this sound symbolic information. Native English speakers were asked to choose the meaning of spoken foreign words from one of four corresponding antonym pairs selected from a previously developed multi-language stimulus set containing both sound symbolic and non-symbolic stimuli. In behavioral (n=9) and fMRI (n=15) experiments, participants showed reliable sensitivity to the sound symbolic properties of the stimulus set, selecting the consistent meaning for the sound symbolic words at above chances rates. There was increased activation for sound symbolic relative to non-symbolic words in left superior parietal cortex, and a cluster in left superior longitudinal fasciculus showed a positive correlation between fractional anisotropy (FA) and an individual's sensitivity to sound symbolism. These findings support the idea that crossmodal correspondences underlie sound symbolism in spoken language.