Journal of Child Language

The present study examined the composition of the early productive vocabulary of eight Korean- and eight English-learning children and the morpho-syntactic, semantic, and pragmatic characteristics of their caregivers' input in order to determine parallels between caregiver input and early lexical development. Vocabulary acquisition was followed using maternal diary and checklists for the Korean-learning children (from a mean age of 1;6 to 1;9) and for the English-learning children (from a mean age of 1;4 to 1;8). Results showed that both Korean-learning and English-learning children acquired significantly more nouns than verbs at the 50-word mark. However, Korean children learned significantly more verbs than did English-learning children. The relative ease with which Korean learners, as compared to English learners, acquired verbs parallels several differences in the linguistic and socio-pragmatic characteristics of the input addressed to them. Korean-speaking caregivers presented more activity-oriented utterances, more verbs, and more salient cues to verbs than did English-speaking caregivers. These data suggest that both general and language-specific factors shape the early lexicon.

One important mechanism suggested to underlie the acquisition of grammar is rule learning. Indeed, infants aged 0 ; 7 are able to learn rules based on simple identity relations (adjacent repetitions, ABB: "wo fe fe" and non-adjacent repetitions, ABA: "wo fe wo", respectively; Marcus et al., 1999). One unexplored issue is whether young infants are able to process both adjacent and non-adjacent repetitions. As the previous studies always compared the two types of repetition structures directly, the ability to learn only one of them was sufficient for successful discrimination in these tasks. The present study reports two experiments, in which we test the ability of infants aged 0 ; 7 to discriminate adjacent and non-adjacent repetition structures against random controls (ABB vs. ABC and ABA vs. ABC). We show that, contrary to some previous proposals, infants aged 0 ; 7 successfully discriminate both repetition types from random controls, but show no spontaneous preference for either of them.

Using the Multiple Indicator Cluster Survey, language comprehension and production were compared in a sample of 101,250 children aged 2 ; 00 to 9 ; 11 and a focus subsample of 38,845 children aged 2 ; 00 to 4 ; 11 from sixteen under-researched developing nations. In the whole sample, comprehension slightly exceeded production; correlations between comprehension and production by country were positive and significant, but varied in size, and the average correlation was positive, significant, and small to medium. Mean comprehension and production varied with child age, reaching an asymptote at 5 ; 00, and correlations between comprehension and production by age were positive, significant, and similar at each age. In the focus subsample, comprehension exceeded production; correlations between comprehension and production by country were positive and significant, but varied in size, and the average correlation was positive, significant, and medium in size. Children in countries with lower standards of living were less likely to demonstrate basic language comprehension or production.

Previous studies have suggested that intonation development in infants and toddlers reflects an interaction between physiological and linguistic influences. The immediate background research for this study, however, was based on vocalizations that were only one syllable in length. By extending the analysis to polysyllabic utterances, the present study evaluated a broader range of physiological constraints on intonation production than the maximally simple context of monosyllabic utterances had permitted. The width and direction of pitch change across one- and two-syllable nuclear tones were acoustically analyzed in utterances produced by 60 children between the ages of 0;6 and 1;11. The results showed that the children controlled the characteristic intonation pattern of English monosyllables by the age of 1;6-1;8. However, even the youngest groups of children produced relatively robust and adult-like intonation contours when the tone-bearing string was polysyllabic, suggesting that the trochaic or dactylic foot is the natural 'unmarked' unit of tone production. The asymmetrical results for one- versus two-syllable tones support the conclusion that width of pitch change largely reflects physiological universals in children's earliest vocalizations and language-specific learning after the age of 1;6. Implications of the findings are also discussed in relation to the Trochaic Template Hypothesis. It is concluded that a bias for trochaic rhythms that some children demonstrate could be based, in part, on the child's sensitivity to physiological constraints on the velocity and range of intonational pitch change.

Past research has indicated that English-learning infants begin segmenting words from speech by 7-5 months of age (Jusczyk & Aslin, 1995). More recent work has demonstrated, however, that 7-5-month-olds' segmentation abilities are severely limited. For example, the ability to segment vowel-initial words from speech reportedly does not appear until 13.5 to 16 months of age (Mattys & Jusczyk, 2001; Nazzi, Dilley, Jusczyk, Shattuck-Hufnagel & Jusczyk, 2005). In this paper, we report on three experiments using the Headturn Preference procedure that investigate both phonetic and phonological factors influencing 11-month-olds' segmentation of vowel-initial words from speech. We replicate earlier findings suggesting that infants have difficulty segmenting vowel-initial words from speech. In addition we extend these findings by demonstrating that under certain conditions, infants are capable of segmenting vowel-initial words from speech at a much younger age than earlier studies have reported. Our findings suggest that infants' ability to segment vowel-initial words from speech is tightly constrained by acoustic-phonetic factors such as pitch movement at the onset of vowel-initial words and segmental strengthening. These experiments underscore the complexity of early word segmentation, and highlight the importance of including contextual factors in developmental models of word segmentation.

Two groups of 20 infants aged 0; 3 experienced either conversational turn taking or random responsiveness of an adult. All infant vocalizations were counted and then each was categorized as a speech-like (syllabic) sound or a nonspeech-like (vocalic) sound. The results of this experiment indicated that turn taking caused changes in the quality of infant vocal sounds. When the adult maintained a give-and-take pattern, the infant produced a higher ratio of syllabic/vocalic sounds. The effect of turn taking on infant vocalizations was discussed in terms of its possible adaptive value for adult responsiveness.

We undertook a detailed computer-implemented acoustic analysis of the speech of a child from 46 to 149 weeks. We measured overall word duration and pitch perturbation (a measure of task-induced stress), in addition to measuring within-word phonetic segments. Results revealed that (1) there were strong age-dependent decreases in word duration but only at a relatively late stage (75–149 weeks); (2) degree of fluency was not correlated with vocal stress; (3) certain segments (i.e. /k/ and /æ/) increased greatly in duration, contributing to the absence of an overall word-duration decrease at an earlier stage (46–79 weeks) and revealing the child's ability to approximate adult-like phonetic norms. Relevance to theories of phonetic development and language change are discussed.

Studies report that infants as young as 1 ; 3 to 1 ; 5 will seek out a novel object in response to hearing a novel label (e.g. Halberda, 2003; Markman, Wasow & Hansen, 2003). This behaviour is commonly known as the 'mutual exclusivity' response (Markman, 1989; 1990). However, evidence for mutual exclusivity does not imply that the infant has associated a novel label with a novel object. We used an intermodal preferential looking task to investigate whether infants aged 1 ; 4 could use mutual exclusivity to guide their association of novel labels with novel objects. The results show that infants can successfully map a novel label onto a novel object, provided that the novel label has no familiar phonological neighbours. Therefore, as early as 1 ; 4, infants can use mutual exclusivity to form novel word-object associations, although this process is constrained by the phonological novelty of a label.

Rethinkinginnateness (RI) is a quixotic book, enthusiastic and visionary. It is hard not to be provoked as each author races full tilt towards their chosen combat. Some readers, like Fodor (1997), respond in kind. Rispoli is more measured. Nonetheless, every reader chooses their own windmills to elevate into giants, and each believes their battle righteous. Are Elman etal. , or is Rispoli ?

Garman (1974), reporting on twenty Tamil children aged three to five, postulated a linguistic strategy and two prelinguistic strategies to explain the results of a question-picture choice task involving sentences with embedded and subordinate clauses. In a reanalysis of his data, we identify four processing strategies and show that some of Garman's findings are better explained not as the outcome of prelinguistic strategies but as an artefact of the experimental design. In fact the data provide evidence of a grammatical sensitivity which is consonant with a sensitivity--demonstrated in recent language--acquisition studies-to the branching direction of the language being acquired.

Ninio & Bruner (1978) added an important dimension to the study of early lexical acquisition by drawing attention to the dialogue-like nature of the mother-child interactions where presumably much language-learning takes place. The authors pointed to the well-established findings that much of the child's early speech consists of names for people and objects (Leopold 1949, Werner & Kaplan 1963, Nelson 1973, Greenfield & Smith 1976). They went on to show that in one familiar type of parent–child interaction, joint picture-book reading, labels are used extensively by the adult and are inserted skilfully into a structured interactional sequence that has the texture of a dialogue (Ninio & Bruner 1978: 6). This dialogue, they suggested, ‘seems… to be a format well suited to the teaching of labelling’ (1978: 12). Subsequent research has also been interpreted as pointing to the teaching potential of joint picture-book reading (Wheeler 1983, Ninio 1983) and the opportunities it affords for situation-specific routines (Snow & Goldfield 1983).

Murray & Trevarthen (1986) experimentally manipulated the behaviours of mothers and infants in an attempt to determine who is responsible for the fine temporal patterning during vocal engagements. In the present note it is argued that the measures of content and style of maternal talk used by Murray and Trevarthen do not directly indicate the ways in which the behaviours of the partners are combined on a moment-to-moment basis.

Elsewhere we have argued on the basis of cross linguistic studies of directionality effects on anaphora in child language, that there is no universal 'forward directionality preference (FDP)'; rather such a preference is linked to languages with specific grammatical properties. Although such a preference has been attested in English acquisition, matched experimental designs in Japanese, Chinese and Sinhalese, for example, do not show this effect. In this paper we argue that current attempts to show that forward directionality effects can also be induced in Japanese acquisition do not succeed in supporting the FDP. Specifics of the design of stimulus sentences in these experiments vary previous cross-linguistic designs so as to favour forward directionality on independent grounds, and confound cross linguistic comparisons. They in fact support a universal structure dependence in children's hypotheses about directionality of anaphora.

Kim, Marcus, Pinker, Hollander & Coppola (1994) argue that the preference children and adults show for regular inflection for verbs and nouns with novel meanings (e.g. The batter flew/flied out to centre field) should be attributed to their grammatically based sensitivity to the derivations of these verbs and nouns. However, it could also be that speakers avoid the use of irregular forms to avoid conveying the conventional meaning associated with the irregular form, such as literally flying to centre field. This paper, in reply to Kim et al. (1994), reinterprets their findings and argues for a semantic/functional account, without resorting to a grammatical account.

In a recent note, Marcus (1995) suggests that the rate of overregularization of English irregular plural nouns is not substantively different from that of English irregular past tense verbs. This finding is claimed to be in conflict with the predictions of connectionist models (Plunkett & Marchman, 1991, 1993) which are said to depend solely on the dominance of regular over irregular forms in determining overregulation errors. However, these conclusions may be premature given that Marcus averaged overregulation rates across irregular nominal forms that varied in token frequency and across samples representing a broad range of children's ages. A connectionist view would predict an interplay between type frequency and other item level factors, e.g. token frequency, as well as differences in the developmental trajectories of the acquisition of nouns and verbs. In this response, we briefly review longitudinal parental report data (N = 26) which indicate that children are significantly more likely to produce noun overregularizations than verb overregularizations across a prescribed age period (1:5 to 2:6). At the same time, these data also show that children are familiar with proportionately more irregular nouns than irregular verbs. These findings are consistent with the predictions of Plunkett & Marchman (1991, 1993) in that the larger regular class affects the frequency of noun errors but also that familiarity with individual irregular nouns tends to reduce the likelihood of overregularizations. In contrast to the conclusion of Marcus (1995), the connectionist approach to English inflectional morphology provides a plausible explanation of the phenomenon of overregularization in both the English plural and past tense systems.

Rispoli (1998) presents data to motivate a model of pronoun case errors in child English. His data consist of relative rates of occurrence of errors involving particular forms in the study of twenty-seven English children between the ages of 2.6 and 4.0. I show that his claim that overextensions of he and him are antagonistic cannot be maintained. I argue that his explanation for why her subjects are more frequent than other errors is insufficient, and suggest an account in terms of relative input frequencies. Finally, I demonstrate that the fundamental assumption underlying Rispoli's model is untenable, and that his findings are not counterevidence for developmental syntax models such as that of Schütze (1997).

Rispoli (1999) suggests that previous studies arguing for a contingency between the case of subject pronouns and the presence/absence of verbal agreement in the acquisition of English (e.g. Schütze, 1997) suffer from methodological problems, and presents new data that fail to support earlier findings. I show that Rispoli's methodology unnecessarily biases his study against finding the predicted contingencies: it fails to take account of children's productive lexical inventory of pronoun forms. As a result, syntactic versus morphological sources of error fail to be distinguished. I explain why this distinction is crucial within the AGR/Tense Omission Model, and clarify its predictions.

The specificity of infants' phonological representations is examined by comparing their sensitivity to mispronunciations of novel and familiar words, using the preferential looking task. 29 children at 1; 2 were trained and tested on familiar and novel word-object pairs. Children showed evidence of sensitivity to mispronunciations of novel and familiar words, indicating detailed phonological representations. Discrepancies between this study and earlier investigations are discussed with reference to differences between habituation and preferential looking tasks.

This article explores whether infants are able to learn words as rapidly as has been reported for preschoolers. Sixty-four infants aged 1;6 were taught labels for either two moving images or two still images. Each image-label pair was presented three times, after which comprehension was assessed using an adaptation of the intermodal preferential looking paradigm. Three repetitions of each label were found to be sufficient for learning to occur, fewer than has previously been reported for infants under two years. Moreover, contrary to a previous finding, learning was equally rapid for infants who were taught labels for moving versus still images. The findings indicate that infants in the early stages of acquiring a vocabulary learn new word-referent associations with ease, and that the learning conditions that allow such learning are less restricted that was previously believed.

This study presents an analysis of children's spontaneous production of words and gestures during an experimental symbol learning task. Namy & Waxman (1998) previously reported that children aged 1;6 interpreted novel arbitrary words (e.g., blicket) and manual gestures (e.g., a dropping motion) as names for object categories (e.g., fruit) but that at 2;2, children interpreted words as names more readily than gestures. Based on this finding and other observational evidence of gesture use, it has been suggested that the younger infants have an initial general symbolic capacity that encompasses both words and gestures. Over time, as infants acquire greater experience with language, words begin to take on a greater priority in the infant's communicative repertoire. The current study examines this hypothesis by analyzing children's spontaneous production of the novel symbols in Namy & Waxman's original task. At 1;6, children rarely produced either the novel words or gestures. At 2;2, children frequently produced both symbolic forms; however, words were produced in a referential manner while gestures were produced in a non-referential manner. These findings are consistent with the argument that over time, words supplant gestures as a symbolic medium.

In a recent commentary, Grinstead (2000) argues against Bates & Goodman's (1999) claims that the development of grammar is contingent on developments in the lexicon, and that, therefore, there is no need for an independent grammar domain. Citing data on the acquisition of negative commands in Catalan and Spanish, Grinstead argues that beyond grammatical elements that are linked with lexical items, there must also exist independently a computational component, which includes grammatical constraints. He argues further that these constraints are observed from the beginning of acquisition. The purpose of this note is, first, to challenge the evidence Grinstead brings to bear in support of this position and, second, to argue further that the acquisition of negative commands in Spanish is better understood in terms of item-based learning combined with low functional load.