Marina Kalashnikova

Maturation of Executive Functioning Skills in Early Sequential Bilingualism.

Previous research has demonstrated that being bilingual from birth is advantageous for the development of skills of social cognition, executive functioning, and metalinguistic awareness due to bilingual childrens extensive experience of processing and manipulating two linguistic systems. The present study investigated whether these cognitive advantages are also evident in sequential bilinguals, i.e., children who began the acquisition of their second language later in childhood. Monolingual English- and English-speaking children acquiring Welsh as a second language matched in age (M age = 4.6), and English receptive vocabulary completed three tasks of attentional control, metalinguistic awareness, and metarepresentation. Sequential bilinguals outperformed monolinguals in the task of attentional control, while no differences were found in the metalinguistic awareness and metarepresentation tasks. These findings suggest that attentional control is the first cognitive component advantaged by early sequential bilingualism and further highlight the benefits of second language exposure in the context of early formal education.

The effects of linguistic experience on the flexible use of mutual exclusivity in word learning

Mutual Exclusivity (ME) is a prominent constraint in language acquisition, which guides children to establish one-to-one mappings between words and referents. But how does unfolding experience of multiple-to-one word-meaning mappings in bilingual childrens environment affect their understanding of when to use ME and when to accept lexical overlap? Three-to-five-year-old monolingual and simultaneous bilingual children completed two pragmatically distinct tasks, where successful word learning relied on either the default use of ME or the ability to accept overlapping labels. All children could flexibly use ME by following the social-pragmatic directions available in each task. However, linguistic experience shaped the development of ME use, whereby older monolinguals showed a greater reliance on the one-to-one mapping assumption, but older bilinguals showed a greater ability to accept lexical overlap. We suggest that flexible use of ME is thus shaped by pragmatic information present in each communicative interaction and childrens individual linguistic experience.

Disambiguation of Novel Labels and Referential Facts: A Developmental Perspective.

Disambiguation refers to children’s tendency to assign novel labels to unfamiliar rather than familiar referents. It is employed as a word-learning strategy, but it remains unknown whether it is a domain-specific phenomenon or a manifestation of more general pragmatic competence. To assess the domain-specificity and development of disambiguation, this study tested children from two age groups (ages 3;7–4;6 and 4;7–5;7) and adults on a disambiguation of novel labels and referential facts paradigm. A linear contrast analysis showed that the difference between disambiguation from labels and disambiguation from facts increased significantly as the participants’ age increased. The results indicate that at the early stages of word learning, children reason by exclusion to disambiguate the meaning of a variety of referential actions, but with increasing understanding about the communicative process, this inferential reasoning develops into a strategy limited to lexical acquisition.

OZI: Australian English Communicative Development Inventory

For more than 20 years, the MacArthur–Bates Communicative Development Inventory (CDI) and its adaptations for languages other than English have been used as reliable measures of infants’ and toddlers’ early receptive and productive vocabulary size. This article introduces the OZI, the Australian English adaptation of the MacArthur–Bates CDI, now normed for 12- to 30-month-old children. The findings of two studies are presented: (1) a comparison study that demonstrated that toddlers (N = 64) acquiring Australian English (24- and 30-month-olds) obtain higher productive vocabulary scores on the OZI than the MacArthur–Bates CDI; and (2) an OZI norming study that included 12- to 30-month-old Australian infants and toddlers (N = 1496). These studies provide (i) evidence for the greater applicability of the OZI for infants and toddlers learning Australian English and (ii) productive vocabulary acquisition norms for Australian English for ages 12–30 months, a research and diagnostic tool highly anticipated by researchers and clinicians around Australia.

The Temporal Modulation Structure of Infant-Directed Speech

The temporal modulation structure of adult-directed speech (ADS) is thought to be encoded by neuronal oscillations in the auditory cortex that fluctuate at different temporal rates. Oscillatory activity is thought to phase-align to amplitude modulations in speech at corresponding rates, thereby supporting parsing of the signal into linguistically relevant units. The temporal modulation structure of infant-directed speech (IDS) is unexplored. Here we compare the amplitude modulation (AM) structure of IDS recorded from mothers speaking, over three occasions, to their 7-, 9-, and 11-month-old infants, and the same mothers speaking ADS. Analysis of the modulation spectrum in each case revealed that modulation energy in the theta band was significantly greater in ADS than in IDS, whereas in the delta band, modulation energy was significantly greater for IDS than ADS. Furthermore, phase alignment between delta- and theta-band AMs was stronger in IDS compared to ADS. This remained the case when IDS and ADS were rate-normalized to control for differences in speech rate. These data indicate stronger rhythmic synchronization and acoustic temporal regularity in IDS compared to ADS, structural acoustic differences that may be important for early language learning.

Mature neural responses to Infant-Directed Speech but not Adult-Directed Speech in Pre-Verbal Infants

Infant directed speech (IDS), the speech register adults use when talking to infants, has been shown to have positive effects on attracting infants’ attention, language learning, and emotional communication. Here event related potentials (ERPs) are used to investigate the neural coding of IDS and ADS (adult directed speech) as well as their discrimination by both infants and adults. Two instances of the vowel /i/, one extracted from ADS and one from IDS, were presented to 9-month-old infants and adults in two oddball conditions: ADS standard/IDS deviant and IDS standard/ADS deviant. In Experiment 1 with adults, the obligatory ERPs that code acoustic information were different for ADS and IDS; and discrimination, indexed by mismatch negativity (MMN) responses, showed that IDS and ADS deviants were discriminated equally well; although, the P3a response was larger for IDS suggesting it captured adults’ attention more than did ADS. In infants the obligatory responses did not differ for IDS and ADS, but for discrimination, while IDS deviants generated both a slow-positive mismatch response (MMR) as well as an adult-like MMN, the ADS deviants generated only an MMR. The presence of a mature adult-like MMN suggests that the IDS stimulus is easier to discriminate for infants.

Mutual exclusivity develops as a consequence of abstract rather than particular vocabulary knowledge

Mutual exclusivity (ME) refers to the assumption that there are one-to-one relations between linguistic forms and their meanings. It is used as a word-learning strategy whereby children tend to map novel labels to unfamiliar rather than familiar referents. Previous research has indicated a relation between ME and vocabulary development, which could either be due to children’s developing knowledge of the labels for familiar objects, or to enhanced general word-learning skills. In this study, ME was related to receptive vocabulary for 17- to 19-month-old children in a novel paradigm where children’s familiarity with the objects and labels was controlled. It was found that infants with larger receptive vocabularies employed ME to a greater extent than infants with a smaller vocabulary size. The results indicate that ME use is more reliable in infants with larger receptive vocabulary size, and, critically, that ME gradually consolidates as an abstract word-learning strategy as infants’ linguistic experience increases.

Novel word learning, reading difficulties, and phonological processing skills

Visual-verbal paired associate learning (PAL) refers to the ability to establish an arbitrary association between a visual referent and an unfamiliar label. It is now established that this ability is impaired in children with dyslexia, but the source of this deficit is yet to be specified. This study assesses PAL performance in children with reading difficulties using a modified version of the PAL paradigm, comprising a comprehension and a production phase, to determine whether the PAL deficit lies in childrens ability to establish and retain novel object-novel word associations or their ability to retrieve the learned novel labels for production. Results showed that while children with reading difficulties required significantly more trials to learn the object-word associations, when they were required to use these associations in a comprehension-referent selection task, their accuracy and speed did not differ from controls. Nevertheless, children with reading difficulties were significantly less successful when they were required to produce the learned novel labels in response to the visual stimuli. Thus, these results indicate that while children with reading difficulties are successful at establishing visual-verbal associations, they have a deficit in the verbal production component of PAL tasks, which may relate to a more general underlying impairment in auditory or phonological processing. Copyright

Neural processing of amplitude and formant rise time in dyslexia.

This study aimed to investigate how children with dyslexia weight amplitude rise time (ART) and formant rise time (FRT) cues in phonetic discrimination. Passive mismatch responses (MMR) were recorded for a/ba/-/wa/contrast in a multiple deviant odd-ball paradigm to identify the neural response to cue weighting in 17 children with dyslexia and 17 age-matched control children. The deviant stimuli had either partial or full ART or FRT cues. The results showed that ART did not generate an MMR in either group, whereas both partial and full FRT cues generated MMR in control children while only full FRT cues generated MMR in children with dyslexia. These findings suggest that children, both controls and those with dyslexia, discriminate speech based on FRT cues and not ART cues. However, control children have greater sensitivity to FRT cues in speech compared to children with dyslexia.

Is It a Name or a Fact? Disambiguation of Reference via Exclusivity and Pragmatic Reasoning.

Adults reason by exclusivity to identify the meanings of novel words. However, it is debated whether, like children, they extend this strategy to disambiguate other referential expressions (e.g., facts about objects). To further inform this debate, this study tested 41 adults on four conditions of a disambiguation task: label/label, fact/fact, label/fact, and fact/label (Scofield & Behrend, ). Participants also provided a verbal explanation for their referent selections to tease apart the underlying processes. Results indicated that adults successfully discerned the target object in the label/label and label/fact condition, yet not the remaining two conditions. Verbal reports indicated that the strategy utilized to disambiguate differed depending upon communicative context. These findings confirm that the tendency to reason by exclusivity becomes restricted to word-learning situations with growing linguistic and communicative experience.