Reiko Mazuka

Bootstrapping word order in prelexical infants: A Japanese–Italian cross-linguistic study ☆

Learning word order is one of the earliest feats infants accomplish during language acquisition [Brown, R. (1973). A first language: The early stages, Cambridge, MA: Harvard University Press.]. Two theories have been proposed to account for this fact. Constructivist/lexicalist theories [Tomasello, M. (2000). Do young children have adult syntactic competence? Cognition, 74(3), 209-253.] argue that word order is learned separately for each lexical item or construction. Generativist theories [Chomsky, N. (1995). The Minimalist Program. Cambridge, MA: MIT Press.], on the other hand, claim that word order is an abstract and general property, determined from the input independently of individual words. Here, we show that eight-month-old Japanese and Italian infants have opposite order preferences in an artificial grammar experiment, mirroring the opposite word orders of their respective native languages. This suggests that infants possess some representation of word order prelexically, arguing for the generativist view. We propose a frequency-based bootstrapping mechanism to account for our results, arguing that infants might build this representation by tracking the order of functors and content words, identified through their different frequency distributions. We investigate frequency and word order patterns in infant-directed Japanese and Italian corpora to support this claim.

Development of executive control and language processing

Research in executive function development has shown that children have poor control of inhibition functions, including the inhibition of prepotent responses, control of attention, and flexibility at rule-shifting. To date, links between the development of executive function and childrens language development have not been investigated explicitly. Yet, recent studies on childrens sentence processing report that children tend to perseverate during sentence processing. We argue that such perseveration may be due to immature executive function.

Functional lateralization of speech processing in adults and children who stutter.

Developmental stuttering is a speech disorder in fluency characterized by repetitions, prolongations, and silent blocks, especially in the initial parts of utterances. Although their symptoms are motor related, people who stutter show abnormal patterns of cerebral hemispheric dominance in both anterior and posterior language areas. It is unknown whether the abnormal functional lateralization in the posterior language area starts during childhood or emerges as a consequence of many years of stuttering. In order to address this issue, we measured the lateralization of hemodynamic responses in the auditory cortex during auditory speech processing in adults and children who stutter, including preschoolers, with near-infrared spectroscopy. We used the analysis–resynthesis technique to prepare two types of stimuli: (i) a phonemic contrast embedded in Japanese spoken words (/itta/ vs. /itte/) and (ii) a prosodic contrast (/itta/ vs. /itta?/). In the baseline blocks, only /itta/ tokens were presented. In phonemic contrast blocks, /itta/ and /itte/ tokens were presented pseudo-randomly, and /itta/ and /itta?/ tokens in prosodic contrast blocks. In adults and children who do not stutter, there was a clear left-hemispheric advantage for the phonemic contrast compared to the prosodic contrast. Adults and children who stutter, however, showed no significant difference between the two stimulus conditions. A subject-by-subject analysis revealed that not a single subject who stutters showed a left advantage in the phonemic contrast over the prosodic contrast condition. These results indicate that the functional lateralization for auditory speech processing is in disarray among those who stutter, even at preschool age. These results shed light on the neural pathophysiology of developmental stuttering.

Young Children's Use of Prosody in Sentence Parsing

Korean childrens ability to use prosodic phrasing in sentence comprehension was studied using two types of ambiguity. First, we examined a word-segmentation ambiguity in which placement of the phrasal boundary leads to different interpretations of a sentence. Next, we examined a syntactic ambiguity in which the same words were differently grouped into syntactic phrases by prosodic demarcation. Children aged 3 or 4 years showed that they could use prosodic information to segment utterances and to derive the meaning of ambiguous sentences when the sentences only contained a word-segmentation ambiguity. However, even 5- to 6-year-old children were not able to reliably resolve the second type of ambiguity, an ambiguity of phrasal grouping, by using prosodic information. The results demonstrate that childrens difficulties in dealing with structural ambiguity are not due to their inability to use prosodic information.

Mothers Speak Less Clearly to Infants Than to Adults A Comprehensive Test of the Hyperarticulation Hypothesis

Infants learn language at an incredible speed, and one of the first steps in this voyage is learning the basic sound units of their native languages. It is widely thought that caregivers facilitate this task by hyperarticulating when speaking to their infants. Using state-of-the-art speech technology, we addressed this key theoretical question: Are sound categories clearer in infant-directed speech than in adult-directed speech? A comprehensive examination of sound contrasts in a large corpus of recorded, spontaneous Japanese speech demonstrates that there is a small but significant tendency for contrasts in infant-directed speech to be less clear than those in adult-directed speech. This finding runs contrary to the idea that caregivers actively enhance phonetic categories in infant-directed speech. These results suggest that to be plausible, theories of infants’ language acquisition must posit an ability to learn from noisy data.

Linguistic Relativity in Japanese and English: Is Language the Primary Determinant in Object Classification?

In the present study, we tested claims by Lucy (1992a, 1992b) that differences between the number marking systems used by Yucatec Maya and English lead speakers of these languages to differentially attend to either the material composition or the shape of objects. In order to evaluate Lucys hypothesis, we replicated his critical object classification experiment using speakers of English and Japanese, a language with a number marking system very similar to that employed by Yucatec Maya. Our results failed to replicate Lucys findings. Both Japanese and English speakers, who were comparable in their cultural and educational backgrounds, classified objects more on the basis of shape than material composition, suggesting that Lucys original findings may have resulted not from differences between the number marking systems of Yucatec Maya and English but rather from differences in the cultural and educational backgrounds of his experimental groups. Alternative accounts of the cognitive consequences of inter-linguistic differences in number marking systems are discussed.

On Parameter Setting and Parsing: Predictions for Cross-Linguistic Differences in Adult and Child Processing

Up until now, studies of natural language processing and acquisition in relation to Universal Grammar Chomsky, 1982 and 1987) have been conducted independently to a large degree. When they have been related, e.g. in studies of relations between language learnability and parsability, these studies have mainly argued that learnability and parsability put functional constraints on Universal Grammar. In contrast, in this paper, we will pursue a program of study of the relations between language processing and acquisition which hypothesizes that Universal Grammar itself significantly determines certain aspects of language processing as well as language acquisition. In particular, we will hypothesize that parameter setting in UG has as one deductive consequence, a systematically different organization of parsing across language types. Since we consider that parameter-setting for UG occurs very early, we predict that this differential organization of parsing is a characteristic of processing in very early stages of language acquisition, as well as in the adult

Brain responses in the processing of lexical pitch-accent by Japanese speakers

Near-infrared spectroscopy was used to elucidate the neural mechanisms underlying the processing of Japanese lexical pitch-accent by adult native speakers of Japanese. We measured cortical hemodynamic responses to a pitch pattern change (high-low vs. low-high) embedded in disyllabic words or pure tones. The results showed that the responses to the pitch pattern change within the words were larger than those for the pure tones in the left temporoparietal region. Activation in the left frontal region was also observed for the perception of pitch pattern change within the words. These results indicate that the left language-related regions contribute to the processing of lexical pitch-accent in native Japanese speakers.

Processing of empty categories in Japanese

Recent experimental research on the processing of empty categories (EC) in English points to the general conclusion that during on-line processing of a sentence, not only is the presence of an EC detected but its linguistically legitimate antecedents are also computed. In this paper, it is argued that, in Japanese, ECs pose serious problems for on-line processing if they are to be processed in a manner similar to English. Initial experimental data indicates that, in Japanese, the processor may not recognize an EC during initial on-line processing of a sentence. It is tentatively suggested that processing of an EC in Japanese may be delayed until after the on-line processing of the structure of a sentence.

Immediate Use of Prosody and Context in Predicting a Syntactic Structure.

Numerous studies have reported an effect of prosodic information on parsing but whether prosody can impact even the initial parsing decision is still not evident. In a visual world eye-tracking experiment, we investigated the influence of contrastive intonation and visual context on processing temporarily ambiguous relative clause sentences in Japanese. Our results showed that listeners used the prosodic cue to make a structural prediction before hearing disambiguating information. Importantly, the effect was limited to cases where the visual scene provided an appropriate context for the prosodic cue, thus eliminating the explanation that listeners have simply associated marked prosodic information with a less frequent structure. Furthermore, the influence of the prosodic information was also evident following disambiguating information, in a way that reflected the initial analysis. The current study demonstrates that prosody, when provided with an appropriate context, influences the initial syntactic analysis and also the subsequent cost at disambiguating information. The results also provide first evidence for pre-head structural prediction driven by prosodic and contextual information with a head-final construction.