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Many studies have shown that input in more than one language influences children's phonemic development. In this study, we examined the neural processes supporting perception of Voice Onset Time (VOT) in bilingual Italian-German children and their monolingual German peers. While German contrasts short-lag and long-lag, Italian contrasts short-lag and voicing lead. We examined whether bilinguals' phonetic/phonological systems for the two languages develop independently or whether they influence each other, and what role language input plays in the formation of phonetic/phonological categories. Forty five-year-old children (16 monolingual German, 24 bilingual Italian-German) were tested in an oddball design expected to elicit a neural Mismatch Response (MMR). The stimuli were bilabial stop VOT contrasts with the short-lag stop, common to both languages, as the standard. Four deviant VOTs were selected: 92 ms and 36 ms lag for German; 112 ms and 36 ms voicing lead for Italian. Bilingual children's language background was assessed using a caregiver questionnaire. Italian-German bilingual 5-year-old children and German monolingual controls showed similar MMRs to German long-lag and Italian voicing lead VOT, except for the 36 ms long-lag deviant; this acoustically difficult distinction did not elicit a robust negative MMR in the bilingual children. The lack of a difference between the bilinguals and monolinguals for voicing lead suggests that the amount of input in Italian for the bilinguals was not sufficient to lead to an advantage compared to the monolingual German children. Alternatively, the finding could indicate that voicing lead is easier to discriminate than voicing lag. [ABSTRACT FROM AUTHOR]

Lateral temporal measures of the auditory evoked potential (AEP) including the T-complex (positive Ta and negative Tb), as well as an earlier negative peak (Na) index maturation of auditory/speech processing. Previous studies have shown that these measures distinguish neural processing in children with typical language development (TD) from those with disorders and monolingual from bilingual children. In this study, bilingual children with Turkish as L1 and German as L2 were compared with monolingual German-speaking children with developmental language disorder (DLD) and monolingual German-speaking children with TD in order to disentangle effects of limited language input vs. reduced perceptual abilities in the processing of speech and non-speech stimuli. Sensory processing reflected by the T-complex (or from lateral temporal electrode sites) was compared in response to a German vowel and a sine-wave tone in the three groups of children, ages 5 through 6 years. Stimuli were presented while children watched a muted video. Auditory evoked potentials (AEPs) were time-locked to the vowels and tones. AEPs to the frequent (standard) stimuli within an oddball paradigm were analyzed at the left (T7) and right (T8) temporal electrode sites.The results revealed language status (monolingual, bilingual, and DLD), stimulus (vowel and tone), and language test measures (receptive and expressive) all influenced the T-complex amplitudes. Particularly, the peak amplitude of Ta was modulated by language status and stimulus type. Bilingual children had significantly more negative Ta responses than the monolingual children with TD for both vowels and tones while DLD children differed from TD children only for the vowel stimulus. The amplitude of the T-complex was overall more negative at the left than at the right site. The Na peak latency was longer for the bilingual group than that observed for the two monolingual groups. The Tb latency was shorter for DLD and bilingual groups than that for TD children in the vowel condition, but no such latency difference between DLD and bilingual children was found. We suggest that the attenuated T-complex for bilingual children indicates continued plasticity of the auditory cortex to allow for learning of novel, second-language speech sounds. [ABSTRACT FROM AUTHOR]

Lexical development in first language (L1) Turkish and second language (L2) German in two- to three-year-old children was examined, using parental vocabulary checklists in Turkish and in German. Children showed strong Turkish dominance in the number of lexical items they produced, which was due to the more frequent exposure to Turkish and higher quality of the input. Their vocabulary in Turkish and German comprised a largely different conceptual make-up, as evidenced by a high conceptual count of items across languages. Translation equivalents made up around 10% of the Total Vocabulary. An exemplary analysis of six noun categories showed that the more domestically oriented categories (Furniture, People) were represented more strongly in Turkish vocabularies, while the Food and Drink category contributed equally to both languages. In Turkish, 18% of words were verbs, whereas in German, verbs constituted only 7% of the children’s vocabularies. A comparison between the parent checklists TIGE (developed for Turkish monolingual children in Turkey) and TILDA (developed for Turkish children growing up in Germany) revealed conceptual differences, which can be attributed to culture-specific developments and use of specific lexical items in the two countries. Therefore, language- and culture-specific instruments should be used to assess early vocabulary skills. [ABSTRACT FROM AUTHOR]