The Neurobiology of Infant Attachment-Trauma and Disruption of Parent-Infant Interactions.

Current clinical literature and supporting animal literature have shown that repeated and profound early-life adversity, especially when experienced within the caregiver-infant dyad, disrupts the trajectory of brain development to induce later-life expression of maladaptive behavior and pathology. What is less well understood is the immediate impact of repeated adversity during early life with the caregiver, especially since attachment to the caregiver occurs regardless of the quality of care the infant received including experiences of trauma. The focus of the present manuscript is to review the current literature on infant trauma within attachment, with an emphasis on animal research to define mechanisms and translate developmental child research. Across species, the effects of repeated trauma with the attachment figure, are subtle in early life, but the presence of acute stress can uncover some pathology, as was highlighted by Bowlby and Ainsworth in the 1950s. Through rodent neurobehavioral literature we discuss the important role of repeated elevations in stress hormone corticosterone (CORT) in infancy, especially if paired with the mother (not when pups are alone) as targeting the amygdala and causal in infant pathology. We also show that following induced alterations, at baseline infants appear stable, although acute stress hormone elevation uncovers pathology in brain circuits important in emotion, social behavior, and fear. We suggest that a comprehensive understanding of the role of stress hormones during infant typical development and elevated CORT disruption of this typical development will provide insight into age-specific identification of trauma effects, as well as a better understanding of early markers of later-life pathology.

Variability across repeated productions in bilingual children speaking Jamaican Creole and English.

PURPOSE: Previous work suggests that variability across repeated productions of the same word may be useful in diagnosing speech sound disorder (SSD) in bilingual children. However, there is debate over what level of variability in transcribed productions should be considered typical even in monolingual speech development. High variability in the input represents a factor that could promote increased production variability in bilinguals. For this reason, the current study examines transcription-based token-to-token variability in bilingual children speaking Jamaican Creole (JC) and English. METHOD: Twenty-five bilingual children aged 3;4-5;1 and twenty-five monolingual children aged 2;9-4;1 from a previous study were recorded producing eleven items in three repetitions. RESULT: Contrary to our hypothesis, bilingual children showed similar rates of token-to-token variability compared to the monolingual children. In a separate analysis of bilingual data across languages, bilingual children were more variable in JC compared to English productions. CONCLUSION: The difference between language contexts suggests that creole languages, which exist on a usage continuum, may be associated with increased variability in production. Our findings suggest that token-to-token production variability may be of similar clinical utility for bilingual and monolingual populations.

Speech Production Accuracy and Variability in Monolingual and Bilingual Children With Cochlear Implants: A Comparison to Their Peers With Normal Hearing.

Purpose This study investigates consonant and vowel accuracy and whole-word variability (also called token-to-token variability or token-to-token inconsistency) in bilingual Spanish-English and monolingual English-speaking children with cochlear implants (CIs) compared to their bilingual and monolingual peers with normal hearing (NH). Method Participants were 40 children between 4;6 and 7;11 (years;months; M age = 6;2), n = 10 each in 4 participant groups: bilingual Spanish-English with CIs, monolingual English with CIs, bilingual Spanish-English with NH, and monolingual English with NH. Spanish and English word lists consisting of 20 words of varying length were generated, and 3 productions of each word were analyzed for percent consonants correct, percent vowels correct, and the presence of any consonant and/or vowel variability. Results Children with CIs demonstrated lower accuracy and more whole-word variability than their peers with NH. There were no differences in rates of accuracy or whole-word variability between bilingual and monolingual children matched on hearing status, and bilingual children had lower accuracy and greater whole-word variability in English than in Spanish. Conclusions High rates of whole-word variability are prevalent in the speech of children with CIs even after many years of CI experience, and bilingual language exposure does not appear to negatively impact phonological development in children with CIs. Contributions to our understanding of underlying sources of speech production variability and clinical implications are discussed.

Association of the Type of Toy Used During Play With the Quantity and Quality of Parent-Infant Communication.

IMPORTANCE: The early language environment of a child influences language outcome, which in turn affects reading and academic success. It is unknown which types of everyday activities promote the best language environment for children. OBJECTIVE: To investigate whether the type of toy used during play is associated with the parent-infant communicative interaction. DESIGN, SETTING, AND PARTICIPANTS: Controlled experiment in a natural environment of parent-infant communication during play with 3 different toy sets. Participant recruitment and data collection were conducted between February 1, 2013, and June 30, 2014. The volunteer sample included 26 parent-infant (aged 10-16 months) dyads. EXPOSURES: Fifteen-minute in-home parent-infant play sessions with electronic toys, traditional toys, and books. MAIN OUTCOMES AND MEASURES: Numbers of adult words, child vocalizations, conversational turns, parent verbal responses to child utterances, and words produced by parents in 3 different semantic categories (content-specific words) per minute during play sessions. RESULTS: Among the 26 parent-infant dyads, toy type was associated with all outcome measures. During play with electronic toys, there were fewer adult words (mean, 39.62; 95% CI, 33.36-45.65), fewer conversational turns (mean, 1.64; 95% CI, 1.12-2.19), fewer parental responses (mean, 1.31; 95% CI, 0.87-1.77), and fewer productions of content-specific words (mean, 1.89; 95% CI, 1.49-2.35) than during play with traditional toys or books. Children vocalized less during play with electronic toys (mean per minute, 2.9; 95% CI, 2.16-3.69) than during play with books (mean per minute, 3.91; 95% CI, 3.09-4.68). Parents produced fewer words during play with traditional toys (mean per minute, 55.56; 95% CI, 46.49-64.17) than during play with books (mean per minute, 66.89; 95% CI, 59.93-74.19) and use of content-specific words was lower during play with traditional toys (mean per minute, 4.09; 95% CI, 3.26-4.99) than during play with books (mean per minute, 6.96; 95% CI, 6.07-7.97). CONCLUSIONS AND RELEVANCE: Play with electronic toys is associated with decreased quantity and quality of language input compared with play with books or traditional toys. To promote early language development, play with electronic toys should be discouraged. Traditional toys may be a valuable alternative for parent-infant play time if book reading is not a preferred activity.

Predictors of token-to-token inconsistency in preschool children with typical speech-language development.

The purpose of this study was to examine potential concurrent predictors and replicate rates of token-to-token inconsistency (inconsistency in repeated productions of the same word) in 43 children with typical speech-language development, ages 2;6 to 4;2. A standard linear regression was used to determine which variables, if any, among age, expressive and receptive vocabulary, and speech sound production abilities predicted token-to-token inconsistency. Inconsistency rates in children from one research site, reported elsewhere, were compared to rates in children from a second research site. The results revealed that expressive vocabulary was the only significant predictor of token-to-token inconsistency in these children. Furthermore, inconsistency rates were similarly high across the two research sites. The findings are discussed in terms of their implications for our theoretical understanding of token-to-token inconsistency and its role in the differential diagnosis of speech sound disorders in children.

Intraword variability in typical speech development.

PURPOSE: Intraword variability (sometimes called token-to-token variability) has been associated with certain types of speech disorder. It has also been documented in typical speech development. The purpose of this study was to investigate intraword variability in typically developing 2- and 3-year-olds to determine expected rates and patterns of variability in typical speech development. METHOD: Participants were 33 children aged 2;6 (years;months) to 3;11 with typical speech development. Three productions of 25 target words were elicited, and an overall variability score was calculated. Response type and the effect of word length were investigated. RESULTS: Variability rates decreased with age; however, the oldest children (ages 3;6-3;11) continued to display considerable variability. The most common response type was variable with no hits (i.e., variable production with none matching the target form) for all age groups, and variability was greatest for longer words. CONCLUSIONS: Variability is prevalent in the speech of typically developing 2- and 3-year-olds and was observed even in the oldest children. Future work is needed to determine at what age this type of phonemic variability is no longer prevalent in typical speech development. Clinicians should use caution in interpreting the presence of intraword variability as indicative of specific subtypes of speech disorder.

Lexical and phonological effects in early word production.

PURPOSE: This study examines the influence of word frequency, phonological neighborhood density (PND), age of acquisition (AoA), and phonotactic probability on production variability and accuracy of known words by toddlers with no history of speech, hearing, or language disorders. METHOD: Fifteen toddlers between 2;0 (years;months) and 2;5 produced monosyllabic target words varying in word frequency, PND, AoA, and phonotactic probability. Phonetic transcription was used to determine (a) whole-word variability and (b) proportion of whole-word proximity (PWP; Ingram, 2002) of each target word produced. RESULTS: Results show a significant effect of PND on PWP and variability (words from dense neighborhoods had higher PWP and lower variability than those from sparse neighborhoods), a significant effect of word frequency on variability (high-frequency words were less variable) but not proximity, and a significant effect of AoA on proximity (earlier acquired words had lower PWP) but not variability. CONCLUSIONS: Results provide new information regarding the role that lexical and phonological factors play in the speech of young children; specifically, several factors are identified that influence variability of production. Additionally, by examining lexical and phonological factors simultaneously, the current study isolates differential effects of the individual factors. Implications for our understanding of emerging phonological representations are discussed.

Insights on blastomere nuclearity.

PURPOSE: To analyze the results of our transferred embryos, especially those that "changed" their blastomere nuclearity from Multinucleated (MN) to Mono-nucleated during development. METHODS: Pregnancies where at least one MN embryo was transferred were retrospectively evaluated and categorized in order to record and follow-up on the ones that were implanted. Embryos were classified as normal (when all blastomeres were mono-nucleated on day one and two of development), corrected (multinucleated embryos on day one that became mono-nucleated on day two) and non-corrected (multinucleated either on day one, on day two or both days). RESULTS: There were 633 transfer cycles analyzed. Thirty-three percent (206) had at least one embryo with a MN blastomere at a given stage of development. Pregnancy and implantation rates were 29.0% and 19.0% for the group of exclusively mono-nucleated embryo transfers, and 28.6% and 15.8% for the group with at least one MN embryo transferred. The pregnancy outcome for "corrected" and "non-corrected" embryos could be corroborated unequivocally in only 9 cases, with an outcome of 8 and 4 normal babies, respectively. CONCLUSIONS: Because the amount of data analyzed is not satisfactorily large, differences were not significantly different; however, a trend may exist showing that normal at term pregnancies obtained from corrected embryos are more likely to occur than those from non-corrected embryos. Nuclear observation on a daily basis should be one of the strategies used to select the best embryos for transferring, to improve implantation rates and avoid multiple pregnancies.

Patterns of intra-word phonological variability during the second year of life.

Phonological representation for adult speakers is generally assumed to include sub-lexical information at the level of the phoneme. Some have suggested, however, that young children operate with more holistic lexical representations. If young children use whole-word representation and adults employ phonemic representation, then a component of phonological development includes a transition from holistic to segmental storage of phonological information. The present study addresses the nature of this transition by investigating the prevalence and patterns of intra-word production variability during the first year of lexical acquisition (1;0-2;0). Longitudinal data from four typically developing children were analysed to determine variability at each age. Patterns of variability are discussed in relation to chronological age and productive vocabulary size. Results show high overall rates of variability, as well as a peak in variability corresponding to the onset of combinatorial speech, suggesting that phonological reorganization may commence somewhat later than previously thought.

Monochorionic triplets after single embryo transfer.

A 40-year-old patient underwent intracytoplasmic sperm injection and assisted hatching, and a single embryo was transferred. Ultrasonography demonstrated a single gestational sac containing monochorionic tri-amniotic pregnancy. Several factors that have been implicated in the aetiology of monozygotic triple pregnancies after IVF appear to be present in this case. To avoid multiple pregnancies after IVF, it is time to have definite predictive factors for the occurrence of monozygotic multiple pregnancies as well as transferring only a single embryo.

Evidence for frequency-based constituents in the mental lexicon: collocations involving the word of.

In this paper, it is hypothesized that units larger than the traditional word, such as two-word collocations and phrases, may be stored in the mental lexicon and accessed holistically. Following previously published work on the Network or Usage-based model of lexical storage (Bybee, 1985, 1995), we suggest that the mechanism determining this constituency is the frequency with which items occur together in natural, connected speech: the collocational frequency. The present study uses a word-monitoring paradigm to investigate reaction times to the English function word of in collocations of varying levels of frequency. A significant effect of collocational frequency was observed; response latencies were longer when the target word of occurred in the very frequent collocations, indicating holistic processing of the frequent phrases. Furthermore, response latencies presented here are considerably longer than those reported in previous studies. This is explained as a result of the hypothesized holistic representation as well as a function of the use of stimuli extracted from natural conversation.