Delayed Language Development in Young Children

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Presence of specific medical diagnoses (e.g., Down syndrome,. Cri du chat syndrome). The final sample after attrition included 30 children: • 17 IC children (9 ...
Delayed Language Development in Young Children raised in Institutional Care is Manifested in the Atypical N400 Component Marina Zhukova1, Sergey Kornilov1,2,3, Marina Vasilyeva1, Anna Letunovskaia1, Rifkat Muhamedrahimov1, Elena Grigorenko1,2,3 1 – Saint-Petersburg State University; 2 – Yale University; 3 – Haskins Laboratories Introduction §  Environmental effects on language development can be investigated in “natural experiment” settings – e.g., by examining cognitive development in children raised in suboptimal environments §  In some countries (including Russia) children left without parental care are raised in institutional settings (IC) – baby homes and orphanages General cognition and social-emotional functioning are the most researched developmental domains of IC children (Rutter, 2000; Pomerleau et al., 2005) §  When the IC conditions are at the level of severe neglect and deprivation (e.g., the BEIP project data), children also show substantial delays in receptive+ expressive language (Windsor et al., 2011; Loman, Wiik, Frenn, Pollak, & Gunnar, 2009) §  Deficits in lexical and grammatical development in IC children persist into the adolescence (Windsor, Moraru, Nelson, Fox, & Zeanah, 2013; Juffer & van IJzendoorn, 2005) Little is known about §  Early lexical development of young IC children §  Neurobiological foundations and locus of the possible language deficits in IC children Current study §  Investigated ERP indices of spoken word (and nonword) processing in a cross-modal picture-word paradigm. Paradigm was modeled after Friedrich & Friederici (2005), which suggests that semantic integration is present in response to phonotactically legal, but NOT to phonotactically illegal words in 19 month-old children §  In a sample of IC children and their age peers raised in biological families (BF)

This research was supported by the Government of the Russian Federation (grant No 14.Z50.31.0027; E.L.G., Principal Investigator) POSTER TEMPLATES BY: www.POSTERPRESENTATIONS.com

Method Participants EEG data was collected from 42 children. Twelve children were excluded due to: •  Fussiness/excessive motor artifacts in the data •  Presence of specific medical diagnoses (e.g., Down syndrome, Cri du chat syndrome)

The final sample after attrition included 30 children: •  17 IC children (9 boys, M = 27.88, SD = 10.07) •  13 BF children (5 boys, M = 31.54, SD = 9.74)

Paradigm We used cross-modal picture-word paradigm (Kornilov et al., 2015) 40 trials x 4 condition = 120 trials 1)  Real word match condition (cat – cat) 2) Real word mismatch condition (cat – bed) 3) Legal pseudoword condition (cat - pl-ara) 4) Illegal pseudoword condition (cat - pv-ara)

EEG Recordings 64 active Ag/AgCl electrodes connected to the actiCHamp EEG amplifier system (Brain Products, Inc) and mounted according to the 10-20 system on an elastic cap

EEG Processing •  Sampled at 1,024 Hz •  Re-referenced the signal to the common average reference •  Filtered offline at (.10 to 35 Hz) + 50 Hz notch •  Segmented into 800 ms epochs with a 100 ms pre-stimulus baseline •  ICA used to correct for ocular artifacts •  Trials with excessive voltage excluded (all children provided at least 14 trials per condition)

Results

Results Illegal pseudoword - (difference) Legal pseudoword

Real word mismatch - (difference) Real word match

IC

IC

BF

BF

BF BF

IC IC

350-550 ms

§  Analyzed amplitudes in the 350-550ms time window, leftlateralized N4 was the focus §  The real word mismatch condition elicited a robust N4 (onesample t = -2.49, p = .004) in the FC3+ cluster in the BF group §  The N4 effect was not significant (t = 2.07, p = .055) in the IC group, and markedly smaller than that of the BF group, two-sample t = 3.36, p = .002), Cohen’s d = -1.21

§  Different topography of responses to illegal vs. legal pseudowords – although both groups showed discrimination, the IC group’s pattern of activation was topographically different and less localized with respect to the N4

Discussion N400 time window

IC BF

N400

References Friedrich, M., & Friederici, A. D. (2005). Phonotactic knowledge and lexical-semantic processing in one-year-olds: Brain responses to words and nonsense words in picture contexts. Journal of Cognitive Neuroscience, 17(11), 1785-1802. Juffer, F., & van IJzendoorn, M. H. (2005). Behavior problems and mental health referrals of international adoptees - A meta-analysis. Jama-Journal of the American Medical Association, 293(20), 2501-2515. Kornilov, S. A., Magnuson, J. S., Rakhlin, N., Landi, N., & Grigorenko, E. L. (2015). Lexical processing deficits in children with developmental language disorder: An event-related potentials study. Development and Psychopathology, 27(2), 459-476. Loman, M., Wiik, K., Frenn, K., Pollak, S., & Gunnar, M. (2009). Postinstitutionalized Children's Development: Growth, Cognitive, and Language Outcomes. Journal of Developmental and Behavioral Pediatrics, 30(5), 426-434. Pomerleau, A., Malcuit, G., Chicoine, J. F., Seguin, R., Belhumeur, C., Germain, P., . . . Jeliu, G. (2005). Health status, cognitive and motor development of young children adopted from China, East Asia, and Russia across the first 6 months after adoption. International Journal of Behavioral Development, 29(5), 445-457. Rutter, M. (2000). Risks and outcomes in developmental psychopathology. British Journal of Psychiatry, 177, 569-569. Windsor, J., Benigno, J. P., Wing, C. A., Carroll, P. J., Koga, S. F., Nelson, C. A., . . . Zeanah, C. H. (2011). Effect of foster care on young children’s language learning. Child Development, 82(4), 1040-1046. Windsor, J., Moraru, A., Nelson, C. A., Fox, N. A., & Zeanah, C. H. (2013). Effect of foster care on language learning at eight years: findings from the Bucharest Early Intervention Project. Journal of Child Language, 40(03), 605-627.

•  Neural indices of spoken word and nonword processing are atypical in IC children at the age of around 30 months

•  IC children show attenuated response to semantic incongruity compared to BF; underspecified lexical representations or processing altered otherwise (functional connectivity and specialization)

•  IC group’s discrimination between phonotactically legal vs. illegal conditions suggests that they are sensitive to wordlikeness based on phonotactics, yet the response differs from typical BF response

•  Role of limited quantity and quality of early communicative interactions, linguistic input, and early caregiving experiences is crucial in IC group