Hostname: page-component-7c8c6479df-ws8qp Total loading time: 0 Render date: 2024-03-28T14:17:57.076Z Has data issue: false hasContentIssue false

Language and cognitive outcomes in internationally adopted children

Published online by Cambridge University Press:  18 April 2011

Inge-Marie Eigsti*
Affiliation:
University of Connecticut
Carol Weitzman
Affiliation:
Yale University School of Medicine
Jillian Schuh
Affiliation:
University of Connecticut
Ashley de Marchena
Affiliation:
Yale University School of Medicine
B. J. Casey
Affiliation:
Weill Cornell Medical College
*
Address correspondence and reprint requests to: Inge-Marie Eigsti, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269; E-mail: inge-marie.eigsti@uconn.edu.

Abstract

This study focuses on the association between language skills and core cognitive processes relative to the duration of institutionalization in children adopted from orphanages abroad. Participants in the adoptive group (n = 46) had arrived in the United States between the ages of 2 and 84 months (mean = 24 months), and had been living in the United States for 1–9 years. Drawing on both experimental and standardized assessments, language skills of the international adoptees differed as a function of length of time spent in an institution and from those of 24 nonadopted controls. Top-down cognitive assessments including measures of explicit memory and cognitive control differed between adopted and nonadopted children, yet differences between groups in bottom-up implicit learning processes were unremarkable. Based on the present findings, we propose a speculative model linking language and cognitive changes to underlying neural circuitry alterations that reflect the impact of chronic stress, due to adoptees' experience of noncontingent, nonindividualized caregiving. Thus, the present study provides support for a relationship between domain-general cognitive processes and language acquisition, and describes a potential mechanism by which language skills are affected by institutionalization.

Type
Regular Articles
Copyright
Copyright © Cambridge University Press 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adams, A., & Gathercole, S. (2000). Limitations in working memory: Implications for language development. International Journal of Language and Communication Disorders, 35, 95116.CrossRefGoogle ScholarPubMed
Albers, L., Johnson, D., Hostetter, M., Iverson, S., & Miller, L. (1997). Health of children adopted from the former Soviet Union and Eastern Europe. Comparison with preadoptive medical records. Journal of the American Medical Association, 278, 922924.Google Scholar
Allport, A. (1987). Selection for action: Some behavioral and neurophysiological considerations of attention and action. In Heuer, H. & Sanders, A. F. (Eds.), Perspectives on perception and action (pp. 395419). Hillsdale, NJ: Erlbaum.Google Scholar
Andresen, I. (1992). Behavioural and school adjustment of 12–13-year old internationally adopted children in Norway: A research note. Journal of Child Psychology and Psychiatry and Allied Disciplines, 33, 427439.CrossRefGoogle ScholarPubMed
Archibald, L. M., & Gathercole, S. E. (2006). Short-term and working memory in specific language impairment. International Journal of Language and Communication Disorders, 41, 675693.Google Scholar
Arnsten, A. F., & Goldman-Rakic, P. S. (1998). Noise stress impairs prefrontal cortical cognitive function in monkeys: Evidence for a hyperdopaminergic mechanism. Archives of General Psychiatry, 55, 362368.Google Scholar
Beckett, C., Maughan, B., Rutter, M., Castle, J., Colvert, E., Groothues, C., et al. (2006). Do the effects of early severe deprivation on cognition persist into early adolescence? Findings from the English and Romanian adoptees study. Child Development, 77, 696711.CrossRefGoogle ScholarPubMed
Brand, A., & Brinich, P. (1999). Behavior problems and mental health contacts in adopted, foster, and nonadopted children. Journal of Child Psychology and Psychiatry and Allied Disciplines, 40, 12211229.CrossRefGoogle ScholarPubMed
Bredy, T. W., Humpartzoomian, R. A., Cain, D. P., & Meaney, M. J. (2003). Partial reversal of the effect of maternal care on cognitive function through environmental enrichment. Neuroscience, 118, 571576.CrossRefGoogle ScholarPubMed
Brown, R. (1973). A first language: The early stages. Cambridge, MA: Harvard University Press.CrossRefGoogle Scholar
Carlson, S. M., & Meltzoff, A. N. (2008). Bilingual experience and executive functioning in young children. Developmental Science, 11, 282298.CrossRefGoogle ScholarPubMed
Cederblad, M., Hook, B., Irhammar, M., & Mercke, A. (1999). Mental health in international adoptees as teenagers and young adults: An epidemiological study. Journal of Child Psychology and Psychiatry and Allied Disciplines, 40, 12391248.CrossRefGoogle Scholar
Choi, Y., & Trueswell, J. C. (in press). Children's (in)ability to recover from garden paths in a verb-final language: Evidence for developing control in sentence processing. Journal of Experimental Child Psychology, 106, 4161.Google Scholar
Chugani, H., Behen, M., Muzik, O., Juhasz, C., Nagy, F., & Chugani, D. (2001). Local brain functional activity following early deprivation: A study of postinstitutionalized Romanian orphans. NeuroImage, 14, 12901301.Google Scholar
Coe, C. L., & Laudenslager, M. L. (2007). Psychosocial influences on immunity, including effects on immune maturation and senescence. Brain, Behavior, and Immunity, 21, 10001008.Google Scholar
Cohen, N. J., Lojkasek, M., Zadeh, Z. Y., Pugliese, M., & Kiefer, H. (2008). Children adopted from China: A prospective study of their growth and development. Journal of Child Psychology and Psychiatry, 49, 458468.CrossRefGoogle Scholar
Conboy, B. T., Sommerville, J. A., & Kuhl, P. K. (2008). Cognitive control factors in speech perception at 11 months. Developmental Psychology, 44, 15051512.CrossRefGoogle Scholar
Croft, C., Beckett, C., Rutter, M., Castle, J., Colvert, E., Groothues, C., et al. (2007). Early adolescent outcomes of institutionally-deprived and non-deprived adoptees: II. Language as a protective factor and a vulnerable outcome. Journal of Child Psychology and Psychiatry, 48, 3144.CrossRefGoogle Scholar
Delis, D., Kramer, J., Kaplan, E., & Ober, B. (1994). The California Verbal Learning Test—Children's version. New York: Psychological Corporation.Google Scholar
Dent, G., Okimoto, D., Smith, M., & Levine, S. (2000). Stress-induced alterations in corticotropin-releasing hormone and vasopressin gene expression in the paraventricular nucleus during ontogeny. Neuroendocrinology, 71, 333342.CrossRefGoogle ScholarPubMed
Dunn, L. M., & Dunn, L. M. (1997). Peabody Picture Vocabulary Test (3rd ed.). Circle Pines, MN: American Guidance Service.Google Scholar
Durston, S., Thomas, K. M., Worden, M. S., Yang, Y., & Casey, B. J. (2002). The effect of preceding context on inhibition: An event-related fMRI study. NeuroImage, 16, 449453.CrossRefGoogle ScholarPubMed
Eigsti, I. M., & Cicchetti, D. (2004). The impact of child maltreatment on expressive syntax at 60 months. Developmental Science, 7, 88102.CrossRefGoogle Scholar
Eigsti, I. M., Weitzman, C., & Mayo, J. (March, 2009). Language acquisition in international adoptees: Influences of explicit but not implicit learning Paper presented at the Georgetown University Roundtable.Google Scholar
Eigsti, I. M., Zayas, V., Mischel, W., Shoda, Y., Ayduk, O., Dadlani, M. B., et al. (2006). Predicting cognitive control from preschool to late adolescence and young adulthood. Psychological Science, 17, 478484.CrossRefGoogle ScholarPubMed
Evans, J. L., Saffran, J. R., & Robe-Torres, K. (2009). Statistical learning in children with specific language impairment. Journal of Speech, Language, and Hearing Research, 52, 321335.CrossRefGoogle ScholarPubMed
Gathercole, S. E., Alloway, T. P., Willis, C., & Adams, A. M. (2006). Working memory in children with reading disabilities. Journal of Experimental Child Psychology, 93, 265281.CrossRefGoogle ScholarPubMed
Gathercole, S. E., Hitch, G. J., Service, E., & Martin, A. J. (1997). Phonological short-term memory and new word learning in children. Developmental Psychology, 33, 966979.CrossRefGoogle ScholarPubMed
Gauthier, K., & Genessee, F. (2007). A comparative study of language outcomes in cross-language adopted children from China. Paper presented at the the 6th International Symposium on Bilingualism.Google Scholar
Geren, J., Snedeker, J., & Ax, L. (2005). Starting over: A preliminary study of early lexical and syntactic development in internationally adopted preschoolers. Seminars in Speech and Language, 26, 4453.CrossRefGoogle Scholar
Glennen, S., & Bright, B. J. (2005). Five years later: Language in school-age internationally adopted children. Seminars in Speech and Language, 26, 86101.CrossRefGoogle ScholarPubMed
Glennen, S., & Masters, M. G. (2002). Typical and atypical language development in infants and toddlers adopted from Eastern Europe. American Journal of Speech–Language Pathology, 11, 417433.CrossRefGoogle Scholar
Glennen, S. L. (2007). Predicting language outcomes for internationally adopted children. Journal of Speech, Language, and Hearing Research, 50, 529548.CrossRefGoogle ScholarPubMed
Gunnar, M. (2001). Effects of early deprivation: Findings from orphanage-reared children. In Nelson, C. A. & Luciana, M. (Eds.), Handbook of cognitive neuroscience (pp. 617629). Cambridge, MA: MIT Press.Google Scholar
Gunnar, M., Morison, S., Chisholm, K., & Schuder, M. (2001). Salivary cortisol levels in children adopted from Romanian orphanages. Development and Psychopathology, 13, 611628.Google Scholar
Gunnar, M., & Quevedo, K. (2007). The neurobiology of stress and development. Annual Review of Psychology, 58, 145173.CrossRefGoogle ScholarPubMed
Gunnar, M., van Dulmen, M., & International Adoption Project Team. (2007). Behavior problems in postinstitutionalized internationally adopted children. Development and Psychopathology, 19, 129148.CrossRefGoogle ScholarPubMed
Gunnar, M. R., Bruce, J., & Grotevant, H. D. (2000). International adoption of institutionally reared children: Research and policy. Development and Psychopathology, 12, 677693.CrossRefGoogle ScholarPubMed
Hanten, G., & Martin, R. C. (2001). A developmental phonological short-term memory deficit: A case study. Brain and Cognition, 45, 164188.Google Scholar
Hart, B., & Risley, T. R. (1995). Meaningful differences in the everyday experience of young American children. Baltimore, MD: Paul H. Brookes.Google Scholar
Hoff-Ginsberg, E. (1991). Mother–child conversation in different social classes and communicative settings. Child Development, 62, 782796.CrossRefGoogle ScholarPubMed
Hoff-Ginsberg, E. (1998). The relation of birth order and socioeconomic status to children's language experience and language development. Applied Psycholinguistics, 19, 603629.CrossRefGoogle Scholar
Hollingshead, A. B. (1975). Four Factor Index of Social Status. Unpublished manuscript, Yale University.Google Scholar
Hudson, C. L., & Eigsti, I. M. (2003). Lexical competency, the overt expression of grammatical structure, and contrasts between pidgins and creoles. Journal of Pidgin and Creole Languages, 18, 179.Google Scholar
Johnson, D. E. (2000). Long-term medical issues in international adoptees. Pediatric Annals, 29, 234241.CrossRefGoogle ScholarPubMed
Johnson, J. S., & Newport, E. L. (1989). Critical period effects in second language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive Psychology, 21, 6099.CrossRefGoogle ScholarPubMed
Kertes, D. A., Gunnar, M. R., Madsen, N. J., & Long, J. D. (2008). Early deprivation and home basal cortisol levels: A study of internationally adopted children. Development and Psychopathology, 20, 473491.CrossRefGoogle Scholar
Kim, W. J., Shin, Y. J., & Carey, M. P. (1999). Comparison of Korean-American adoptees and biological children of their adoptive parents: A pilot study. Child Psychiatry and Human Development, 29, 221228.CrossRefGoogle ScholarPubMed
Kirschbaum, C., Wolf, O. T., May, M., Wippich, W., & Hellhammer, D. H. (1996). Stress- and treatment-induced elevations of cortisol levels associated with impaired declarative memory in healthy adults. Life Science, 58, 14751483.CrossRefGoogle ScholarPubMed
Krakow, R. A., Tao, S., & Roberts, J. (2005). Adoption age effects on English language acquisition: Infants and toddlers from China. Seminars in Speech and Language, 26, 3343.CrossRefGoogle ScholarPubMed
Kuhl, P. K. (2008). Linking infant speech perception to language acquisition: Phonetic learning predicts language growth. In McCardle, P., Colombo, J., & Freund, L. (Eds.), Infant pathways to language: Methods, models, and research directions (pp. 213243). New York: Erlbaum.Google Scholar
Liston, C., McEwen, B., & Casey, B. J. (2009). Psychosocial stress reversibly disrupts prefrontal processing and attentional control. Proceedings of the National Academy of Sciences of the United States of America, 106, 912917.CrossRefGoogle ScholarPubMed
Liston, C., Miller, M. M., Goldwater, D. S., Radley, J. J., Rocher, A. B., Hof, P. R., et al. (2006). Stress-induced alterations in prefrontal cortical dendritic morphology predict selective impairments in perceptual attentional set-shifting. Journal of Neuroscience, 26, 78707874.Google Scholar
Liu, D., Diorio, J., Day, J. C., Francis, D. D., & Meaney, M. J. (2000). Maternal care, hippocampal synaptogenesis and cognitive development in rats. Nature Neuroscience, 3, 799806.CrossRefGoogle ScholarPubMed
Luine, V., Martinez, C., Villegas, M., Magarinos, A. M., & McEwen, B. S. (1996). Restraint stress reversibly enhances spatial memory performance. Physiology & Behavior, 59, 2732.CrossRefGoogle ScholarPubMed
Lupien, S. J., & McEwen, B. S. (1997). The acute effects of corticosteroids on cognition: Integration of animal and human model studies. Brain Research Reviews, 24, 127.Google Scholar
Lyon, G. R., Alexander, D., & Yaffe, S. (1997). Progress and promise in research in learning disabilities. Learning Disabilities: A Multidisciplinary Journal, 8, 16.Google Scholar
Marshall, P. J., & Kenney, J. W. (2009). Biological perspectives on the effects of early psychosocial experience. Developmental Review, 29, 96119.CrossRefGoogle Scholar
Maye, J., Werker, J., & Gerken, L. A. (2002). Infant sensitivity to distributional information can affect phonetic discrimination. Cognition, 82, 101111.Google Scholar
McGuinness, T., McGuinness, J., & Dyer, J. (2000). Risk and protective factors in children adopted from the former Soviet Union. Journal of Pediatric Health Care, 14, 109116.Google Scholar
Meaney, M. J., Szyf, M., & Seckl, J. R. (2007). Epigenetic mechanisms of perinatal programming of hypothalamic–pituitary–adrenal function and health. Trends in Molecular Medicine, 13, 269277.Google Scholar
Miller, L. C., & Hendrie, N. (2000). Health of children adopted from China. Pediatrics, 105, E76.CrossRefGoogle ScholarPubMed
Monk, C. S., & Nelson, C. A. (2002). The effects of hydrocortisone on cognitive and neural function: A behavioral and event-related potential investigation. Neuropsychopharmacology, 26, 505519.CrossRefGoogle ScholarPubMed
Nelson, C. A. 3rd, Zeanah, C. H., Fox, N. A., Marshall, P. J., Smyke, A. T., & Guthrie, D. (2007). Cognitive recovery in socially deprived young children: The Bucharest Early Intervention Project. Science, 318, 19371940.CrossRefGoogle ScholarPubMed
Newcomer, J. W., Selke, G., Melson, A. K., Hershey, T., Craft, S., Richards, K., et al. (1999). Decreased memory performance in healthy humans induced by stress-level cortisol treatment. Archives of General Psychiatry, 56, 527533.CrossRefGoogle ScholarPubMed
Novick, J. M., Trueswell, J. C., & Thompson-Schill, S. L. (2005). Cognitive control and parsing: reexamining the role of Broca's area in sentence comprehension. Cognitive and Affective Behavioral Neuroscience, 5, 263281.Google Scholar
O'Connor, T., & Rutter, M. (2000). Attachment disorder behavior following early severe deprivation: Extension and longitudinal follow-up. English and Romanian Adoptees Study Team. Journal of the American Academy of Child & Adolescent Psychiatry, 39, 703712.CrossRefGoogle ScholarPubMed
O'Connor, T. G., Rutter, M., Beckett, C., Keaveney, L., & Kreppner, J. M. (2000). The effects of global severe privation on cognitive competence: extension and longitudinal follow-up. English and Romanian Adoptees Study Team. Child Development, 71, 376390.CrossRefGoogle ScholarPubMed
O'Jile, J. R., Schrimsher, G. W., & O'Bryant, S. E. (2005). The California Verbal Learning Test—Children's Version: Relation to factor indices of the Wechsler Intelligence Scale for Children (3rd ed.). Journal of Clinical and Experimental Neuropsychology, 27, 815822.CrossRefGoogle Scholar
Plomin, R., Pedersen, N. L., Lichtenstein, P., & McClearn, G. E. (1994). Variability and stability in cognitive abilities are largely genetic later in life. Behavioral Genetics, 24, 207215.Google Scholar
Pollock, K. E. (2005). Early language growth in children adopted from China: Preliminary normative data. Seminars in Speech and Language, 26, 2232.Google Scholar
Roberts, J. A., Pollock, K. E., Krakow, R., Price, J., Fulmer, K. C., & Wang, P. P. (2005). Language development in preschool-age children adopted from China. Journal of Speech, Language, and Hearing Research, 48, 93107.Google Scholar
Rodrigues, A., & Befi-Lopes, D. M. (2009). Phonological working memory and its relationship with language development in children. Pro Fono, 21, 6368.Google Scholar
Roid, G. (2003). Stanford–Binet Intelligence Scales (5th ed.). Itasca, IL: Riverside Publishing.Google Scholar
Roy, P., Rutter, M., & Pickles, A. (2000). Institutional care: risk from family background or pattern of rearing? Journal of Child Psychology and Psychiatry and Allied Disciplines, 41, 139149.Google Scholar
Rutter, M. (1998). Developmental catch-up, and deficit, following adoption after severe global early privation: English and Romanian Adoptees (ERA) Study Team. Journal of Child Psychology and Psychiatry, 39, 465476.Google Scholar
Rutter, M. (2007). Proceeding from observed correlation to causal inference: The use of natural experiments. Perspectives on Psychological Science, 2, 377395.CrossRefGoogle ScholarPubMed
Rutter, M., & O'Connor, T. G. (2004). Are there biological programming effects for psychological development? Findings from a study of Romanian adoptees. Developmental Psychology, 40, 8194.CrossRefGoogle ScholarPubMed
Saetersdal, B., & Dalen, M. (1991). Norway: Intercountry adoptions in a homogeneous country. In Altstein, H. & Simon, R. (Eds.), Intercountry adoption: A multinational perspective (pp. 83108). New York: Praeger.Google Scholar
Saffran, J. R., Aslin, R. N., & Newport, E. L. (1996). Statistical learning by 8-month-old infants. Science, 274, 19261928.Google Scholar
Saffran, J. R., Johnson, E. K., Aslin, R. N., & Newport, E. L. (1999). Statistical learning of tone sequences by human infants and adults. Cognition, 70, 2752.CrossRefGoogle Scholar
Sandi, C., Loscertales, M., & Guaza, C. (1997). Experience-dependent facilitating effect of corticosterone on spatial memory formation in the water maze. European Journal of Neuroscience, 9, 637642.Google Scholar
Scott, K., Roberts, J., & Krakow, R. (2008). Oral and written language development of children adopted from China. American Journal of Speech and Language Pathology, 17, 150160.Google Scholar
Semel, E., Wiig, E. H., & Secord, W. A. (2003). Clinical evaluation of language fundamentals (4th ed.). San Antonio, TX: Harcourt Assessment.Google Scholar
Semel, E., Wiig, E. H., & Secord, W. A. (2004). CELF—Preschool (2nd ed.). San Antonio, TX: Harcourt Assessment.Google Scholar
Shirtcliff, E. A., Coe, C. L., & Pollak, S. D. (2009). Early childhood stress is associated with elevated antibody levels to herpes simplex virus type 1. Proceeding of the National Academy of Sciences of the United States of America, 106, 29632967.CrossRefGoogle ScholarPubMed
Smyke, A. T., Dumitrescu, A., & Zeanah, C. H. (2002). Attachment disturbances in young children. I: The continuum of caretaking casualty. Journal of the American Academy of Child & Adolescent Psychiatry, 41, 972982.CrossRefGoogle ScholarPubMed
Snowling, M., Bishop, D. V., & Stothard, S. E. (2000). Is preschool language impairment a risk factor for dyslexia in adolescence? Journal of Child Psychology and Psychiatry and Allied Disciplines, 41, 587600.CrossRefGoogle ScholarPubMed
Teyler, T., & DiScenna, P. (1987). Long-term potentiation. Annual Review of Neuroscience, 10, 131161.CrossRefGoogle ScholarPubMed
Tottenham, N., Hare, T. A., Quinn, B. T., McCarry, T. W., Nurse, M., Gilhooly, T., et al. (2010). Prolonged institutional rearing is associated with atypically larger amygdala volume and difficulties in emotion regulation. Developmental Science, 13, 4661.Google Scholar
Tremblay, P., & Gracco, V. L. (2006). Contribution of the frontal lobe to externally and internally specified verbal responses: fMRI evidence. NeuroImage, 33, 947957.CrossRefGoogle ScholarPubMed
Ullman, M. T. (2001). A neurocognitive perspective on language: The declarative/procedural model. Nature Reviews Neuroscience, 2, 717726.CrossRefGoogle ScholarPubMed
Vaidya, C. J., Austin, G., Kirkorian, G., Ridlehuber, H. W., Desmond, J. E., Glover, G. H., et al. (1998). Selective effects of methylphenidate in attention deficit hyperactivity disorder: A functional magnetic resonance study. Proceedings of the National Academy of Sciences of the United States of America, 95, 1449414499.Google Scholar
van der Vegt, E. J., van der Ende, J., Ferdinand, R. F., Verhulst, F. C., & Tiemeier, H. (2009). Early childhood adversities and trajectories of psychiatric problems in adoptees: Evidence for long lasting effects. Journal of Abnormal Child Psychology, 37, 239249.CrossRefGoogle ScholarPubMed
van IJzendoorn, M. H., Bakermans-Kranenburg, M. J., & Juffer, F. (2007). Plasticity of growth in height, weight, and head circumference: Meta-analytic evidence of massive catch-up after international adoption. Journal of Developmental and Behavioral Pediatrics, 28, 334343.Google Scholar
van Londen, W. M., Juffer, F., & van IJzendoorn, M. H. (2007). Attachment, cognitive, and motor development in adopted children: Short-term outcomes after international adoption. Journal of Pediatric Psychology, 32, 12491258.Google Scholar
Verhulst, F., Althaus, M., & Versluis-den Bieman, H. (1990a). Problem behavior in international adoptees: I. An epidemiological study. Journal of the American Academy of Child & Adolescent Psychiatry, 29, 94103.Google Scholar
Verhulst, F., Althaus, M., & Versluis-den Bieman, H. (1990b). Problem behavior in international adoptees: II. Age at placement. Journal of the American Academy of Child & Adolescent Psychiatry, 29, 104111.Google Scholar
Whetten, K., Ostermann, J., Whetten, R. A., Pence, B. W., O'Donnell, K., Messer, L. C., et al. (2009). A comparison of the wellbeing of orphans and abandoned children ages 6–12 in institutional and community-based care settings in 5 less wealthy nations. PLoS One, 4, e8169.Google Scholar
Windsor, J., Glaze, L., Koga, S., & The Bucharest Early Intervention Project Core Group. (2007). Language acquisition with limited input: Romanian institution and foster care. Journal of Speech, Language and Hearing Research, 50, 13651381.Google Scholar
Wismer Fries, A. B., Shirtcliff, E. A., & Pollak, S. D. (2008). Early experience in humans is associated with changes in neuropeptides critical for regulating social behavior. Proceedings of the National Academy of Sciences of the United States of America, 102, 1723717240.CrossRefGoogle Scholar
Wolkowitz, O. M., Reus, V. I., Weingartner, H., Thompson, K., Breier, A., Doran, A., et al. (1990). Cognitive effects of corticosteroids. American Journal of Psychiatry, 147, 12971303.Google Scholar
Wong, V., Lee, P. W., Lieh-Mak, F., Yeung, C. Y., Leung, P. W., & Luk, S. L. (1992). Language screening in preschool Chinese children. European Journal of Disorders of Communication, 27, 247264.Google Scholar
Yeung, H. H., & Werker, J. F. (2009). Learning words' sounds before learning how words sound: 9-Month-olds use distinct objects as cues to categorize speech information. Cognition, 113, 234243.Google Scholar