EXPLORING THE CRITICAL PERIOD HYPOTHESIS: PERSPECTIVES, THEORIES, AND IMPLICATIONS FOR LANGUAGE ACQUISITION

From 1975-1986 6 boys with congenital nephrogenic diabetes insipidus were diagnosed at the age of 3 months to 10 years. Symptoms appeared within the first few weeks of life. The diagnosis was confirmed by polyuria, low urinary osmolality (97-225 mosm/kg H20), hypernatraemia (max. 171 mmol/l) and the missing response to vasopressin. The treatment was variable; 4 boys received only hydrochlorothiazide (2-2.5 mg/kg/d) which lead to a reduction of the daily urinary volume of 26-44%. Hyperelectrolytaemia disappeared and a normal thriving could be achieved. Later an additional treatment with indomethacin (2 mg/kg/d) was necessary in 3 boys because of an increase of polyuria; there was a further reduction of the daily urinary volume of 50-60%. The combination of hydrochlorothiazide and indomethacin in the treatment of the congenital nephrogenic diabetes insipidus was well tolerated and seems to be--especially during the first few years of life--a necessary and effective treatment which allows a normal thriving and psychointellectual development.

Pediatric AIDS-Therapeutic Successes Built on a Foundation of Pediatric Clinical Pharmacology with Pharmacokinetic-Pharmacodynamic Modeling.

2 - Growth and Development

Anaesthesia for children is tempered by changes that occur during both growth and development. Drug dose is affected by size and clearance maturation processes as well as the changing body composition that occurs with age. All organ systems undergo these maturation changes and most are complete within the first few years of life. Normal physiological variables in infancy and childhood are quite different from adults. The central nervous, cardiovascular, and respiratory systems are particularly important. Cerebral immaturity and plasticity impacts sensitivity to drugs, pain responses, and behaviour and increases potential harm from apoptosis with anaesthesia. The heart undergoes a transition from fetal to adult circulation during the first few weeks of life. Undiagnosed congenital defects are not uncommon. The neonate is very susceptible to conditions that trigger an increase in pulmonary vascular resistance, with reversion to fetal circulatory patterns. Respiratory anatomy and mechanics affect the propensity to apnoea, airway maintenance, artificial ventilation modalities, uptake of inhalational agents, and tracheal tube sizes. Metabolic rate and oxygen requirements increase with decreasing age. This physiology influences diverse aspects that include the rate of desaturation during apnoea, hypoglycaemia during starvation, cardiac output, drug metabolism, fluid requirements, and heat production or loss.

Varying trajectories of infant television viewing over the first four years of life: Relations to language development and executive functions

Auditory Brain Development in Children with Hearing Loss – Part Two

Every normal child acquires a language, his first language (or ‘native tongue’), in the first few years of life. There are exceptions, on either physiological (e.g. deafness) or social grounds (e.g. ‘wolf children’); but usually a child can communicate freely by the time he goes to school. Beyond puberty, our command of language shows little progress, though in some areas – the vocabulary, for instance – learning continues throughout our life span. First language acquisition is thus primary in at least two ways: in terms of sequence (‘first’) and in terms of (mostly life-long) importance.

478 LANGUAGE, VOLUME 76, NUMBER 2 (2000) Second language acquisition and the critical period hypothesis. Ed. by David Birdsong. (Second language acquisition research: Theoretical and methodological issues 3.) Mahwah, NJ: Lawrence Erlbaum, 1999. Pp. x, 191. The third in a series on theoretical and methodological issues in second language acquisition (SLA) research, this volume was inspired by the 1996 Association Internationale de Linguistique Appliquée symposium, 'New perspectives on the critical period for SLA'. The editor notes in his introductory chapter (1-18) that several versions of the critical period hypothesis (CPH) are represented in the book, allowing a broad perspective on the issue. In the six chapters that follow, international contributors to the volume are evenly divided in the discussion for and against critical periods in SLA. Diversifying the volume are the range of disciplines that take up the issue and the variety of evidence put forth, including but not limited to morphological, syntactic, and phonological data. The three chapters following the introduction present data from SLA studies that support the CPH. Starting from a neurophysiological approach, Christine M. Weber-Fox and Helen T. Neville (23-36) present the hypothesis that cerebral subsystems for semantics and grammar are differentially affected by critical periods (CPs). The authors' incorporation of both behavioral and electrophysiological research methods provides compelling evidence for this hypothesis . Tames R. Hurford and Simon Kirby (39-62) describe simulations that suggest that evolutionary processes contribute to a CP and discuss the implications for SLA briefly. Lynn Eubank and Kevin R. Gregg (65-93) bring a thorough linguistic theory analysis of the CPH to the volume. Asserting that CPHs in adult SLA demand refinement, the authors demonstrate ways that this refinement can come from linguistic theory. Also discussed in this chapter are fundamental distinctions of critical and/or sensitive periods and the role of physiological evidence for CPs in SLA. Three remaining chapters provide counter explanations that also fit the facts of SLA. James E. Flege (101-27) examines the discontinuity predicted by CPH vs. linear function in second language pronunciation and age of arrival. One view offered is that second language phonological production is limited by accuracy in first language perception. Theo Bongaerts (133-55) reports on three studies that he and his colleagues performed which attempted to address the concern that ultimate attainment studies focus on advanced learners. This chapter suggests that motivation , access, and training in perception and production may contribute to high levels of phonological attainment. The identification of native-like late learners of English and French from Dutch-speaking backgrounds supports this suggestion. In the final chapter (161-78), Ellen Bialystok and Kenji Hakuta challenge the assumption of causality between age and level of attainment. They explore results that fail to support the CPH in both the linguistic and cognitive evidence, concluding that there is reason to accept a null hypothesis contradicting the CPH. The 'younger equals better' hypothesis for SLA remains under advisement. In this regard the virtue of the contributions presented here is that they offer a broad scope for future research. Researchers, graduate students, and teachers will find this volume a useful equilibration of the issues. [Daniel O. Jackson , University of Pennsylvania.] The virtues of language: History in language , linguistics and texts. Ed. by Dieter Stein and Rosanna Sornicola. Amsterdam: John Benjamins, 1998. Pp. viii, 232. This collection of thirteen essays is dedicated to the memory of Thomas Frank (1925-1990), who held the Chair ofthe History ofEnglish at the University of Naples from 1982 until his death. The first essay, E. F. Konrad Koerner's revised obituary article (originally published in Historiographia Ling üistica 17.421-26 [1990]), summarizes the honorée's many accomplishments over a long and distinguished career (3-10). It contains his bibliography from 1953-1996, which includes a number of studies in the history of linguistics such as a monograph on Bishop Tohn Wilkins's (1714-1792) Essay towards a real character and a philosophical language of 1668 (Guida: Naples, 1979). Rosanna Sornicola's "Thomas Frank in the Neapolitan environment' (11-14) is a historical survey of Frank's career in Naples—from his days as a teaching assistant in English atthe Neapolitan Istituto Universitario...

Reviewed by: Second language acquisition by Roumyana Slabakova Tania Ionin Second language acquisition. By Roumyana Slabakova. Oxford: Oxford University Press, 2016. Pp. xxi, 483. ISBN 9780199687275. $40. Introduction This book is a textbook of second language acquisition (SLA) written within the theoretical framework of the generative approach to SLA research. The intended readers are advanced undergraduate students and graduate students who have some background in linguistics, in particular in syntax and semantics. The text is intended first and foremost for students with a prior background in generative linguistics. While the main linguistic concepts are explained when they are introduced, such explanations are necessarily brief, and students with no prior background in linguistics would find the more technical parts of the text somewhat difficult to follow. However, students or other readers who have a general interest in language and/or language acquisition, but lack a background in generative linguistics, should still be able to follow the main concepts presented in the book. This textbook is quite unique in that, while its focus is on theoretical research on SLA, it explicitly makes the link to potential pedagogical relevance of the research findings. Brief summary The book consists of thirteen chapters, divided into three parts. Each chapter ends with a section of exercises; at the end of the book are a glossary, references, and an index. Part I, ‘Language’, provides a brief overview of the relevant background information that readers need to have in order to fully appreciate the rest of the book. Ch. 1, ‘Language architecture’, lays out the central argument of generative linguistics for the innateness of language and introduces the reader to several famous proposals on the structure of the language faculty. Ch. 1 then addresses the task faced by a second language learner and lays out the logic of the methodology used in generative SLA research. Ch. 2, ‘Language variation’, walks the reader through the history of the generative study of language variation, from principles and parameters through the minimalist program. Like Ch. 1, Ch. 2 ends by considering the implications of the theoretical linguistic research for the learning task of a second language learner. The goal of Ch. 3, ‘The psychological reality of language in use’, is to prepare the reader for later chapters that address second language processing by reviewing the central models and findings of the literature on language processing and psycholinguistics more generally. Part II, ‘Language acquisition’, has the goal of placing the study of SLA into the study of language acquisition as a whole by considering a number of different language-acquisition scenarios. The focus of this part is on the respective contributions of age of acquisition and of input quantity and quality to the task of language acquisition. Ch. 4, ‘The critical period hypothesis’, goes over the history of critical period studies and addresses the debate about the existence of critical or sensitive periods in SLA. This chapter also considers the role of input, bringing together a number of quite distinct phenomena, including variable input, comparisons between heritage speakers and second language learners, and variability among native speakers at different educational levels. Ch. 5, ‘First language acquisition, two first languages’, provides an overview of the process of first language acquisition; most of the chapter is devoted to monolingual first language acquisition, but the last section discusses simultaneous bilinguals, who form a natural link between monolinguals and adult second language learners. In Ch. 6, ‘Child second language, multilingual and heritage language acquisition, language attrition’, a variety of other types of language acquisition scenarios are discussed. Throughout this chapter, and especially in the last section, the focus is, once again, on the relative contributions of age of acquisition and input quantity and quality to the outcome of the language acquisition process. The position taken in this chapter, and [End Page e198] throughout the rest of the book, is that the effects of age can potentially be overridden by rich input, and that universal grammar remains active in SLA by adults. Part III, ‘Second language acquisition’, is the heart of the book. In addition to providing an overview of SLA research in the core areas of linguistics (with the one exception of...

478 LANGUAGE, VOLUME 76, NUMBER 2 (2000) Second language acquisition and the critical period hypothesis. Ed. by David Birdsong. (Second language acquisition research: Theoretical and methodological issues 3.) Mahwah, NJ: Lawrence Erlbaum, 1999. Pp. x, 191. The third in a series on theoretical and methodological issues in second language acquisition (SLA) research, this volume was inspired by the 1996 Association Internationale de Linguistique Appliquée symposium, 'New perspectives on the critical period for SLA'. The editor notes in his introductory chapter (1-18) that several versions of the critical period hypothesis (CPH) are represented in the book, allowing a broad perspective on the issue. In the six chapters that follow, international contributors to the volume are evenly divided in the discussion for and against critical periods in SLA. Diversifying the volume are the range of disciplines that take up the issue and the variety of evidence put forth, including but not limited to morphological, syntactic, and phonological data. The three chapters following the introduction present data from SLA studies that support the CPH. Starting from a neurophysiological approach, Christine M. Weber-Fox and Helen T. Neville (23-36) present the hypothesis that cerebral subsystems for semantics and grammar are differentially affected by critical periods (CPs). The authors' incorporation of both behavioral and electrophysiological research methods provides compelling evidence for this hypothesis . Tames R. Hurford and Simon Kirby (39-62) describe simulations that suggest that evolutionary processes contribute to a CP and discuss the implications for SLA briefly. Lynn Eubank and Kevin R. Gregg (65-93) bring a thorough linguistic theory analysis of the CPH to the volume. Asserting that CPHs in adult SLA demand refinement, the authors demonstrate ways that this refinement can come from linguistic theory. Also discussed in this chapter are fundamental distinctions of critical and/or sensitive periods and the role of physiological evidence for CPs in SLA. Three remaining chapters provide counter explanations that also fit the facts of SLA. James E. Flege (101-27) examines the discontinuity predicted by CPH vs. linear function in second language pronunciation and age of arrival. One view offered is that second language phonological production is limited by accuracy in first language perception. Theo Bongaerts (133-55) reports on three studies that he and his colleagues performed which attempted to address the concern that ultimate attainment studies focus on advanced learners. This chapter suggests that motivation , access, and training in perception and production may contribute to high levels of phonological attainment. The identification of native-like late learners of English and French from Dutch-speaking backgrounds supports this suggestion. In the final chapter (161-78), Ellen Bialystok and Kenji Hakuta challenge the assumption of causality between age and level of attainment. They explore results that fail to support the CPH in both the linguistic and cognitive evidence, concluding that there is reason to accept a null hypothesis contradicting the CPH. The 'younger equals better' hypothesis for SLA remains under advisement. In this regard the virtue of the contributions presented here is that they offer a broad scope for future research. Researchers, graduate students, and teachers will find this volume a useful equilibration of the issues. [Daniel O. Jackson , University of Pennsylvania.] The virtues of language: History in language , linguistics and texts. Ed. by Dieter Stein and Rosanna Sornicola. Amsterdam: John Benjamins, 1998. Pp. viii, 232. This collection of thirteen essays is dedicated to the memory of Thomas Frank (1925-1990), who held the Chair ofthe History ofEnglish at the University of Naples from 1982 until his death. The first essay, E. F. Konrad Koerner's revised obituary article (originally published in Historiographia Ling üistica 17.421-26 [1990]), summarizes the honorée's many accomplishments over a long and distinguished career (3-10). It contains his bibliography from 1953-1996, which includes a number of studies in the history of linguistics such as a monograph on Bishop Tohn Wilkins's (1714-1792) Essay towards a real character and a philosophical language of 1668 (Guida: Naples, 1979). Rosanna Sornicola's "Thomas Frank in the Neapolitan environment' (11-14) is a historical survey of Frank's career in Naples—from his days as a teaching assistant in English atthe Neapolitan Istituto Universitario...

Language development in the first few years of life is critical for later academic and social success. With the increasing use of digital devices among preschoolers, there have been concerns about the potential impact of screen time on language outcomes. Existing research presents mixed findings, making it necessary to synthesize current evidence. This systematic review aimed to examine and synthesize empirical evidence on the relationship between screen time and language development in early childhood, with emphasis on factors such as device type, content quality, socioeconomic status, and parent-child interaction.Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted in the Cochrane Library, PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), EBSCO Open Dissertations, ScienceDirect, and Clinicaltrials.gov for studies published between January 1, 2020, and February 17, 2025.Our inclusion criteria required studies published in the English language, assessed screen time exposure, and measured language outcomes in typically developing preschoolers. Data were extracted using a standardized form. The risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2), the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I), and the Joanna Briggs Institute (JBI) Critical Appraisal tools. The overall certainty of the evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework.A total of eight studies met the inclusion criteria, mostly consisting of cross-sectional studies that involved diverse patient populations with sample sizes ranging from 83 to 4,907 participants. The participants were primarily children aged three to six years and/or their parents. These studies mainly focused on measuring the duration of screen time, which averaged between approximately 1.39 and 2.65 hours per day. One study analyzed 44 mobile applications for their learning goals and educational potential. The most commonly reported outcomes were related to language development and vocabulary acquisition, which were assessed through parental surveys and developmental scales.Synthesized evidence suggests that high levels of unsupervised or passive screen time are often linked to weaker language development outcomes in preschoolers. However, screen use that is interactive, educational, and involves caregiver participation appears to mitigate these potential effects. The overall certainty of this evidence, however, remains limited. Future research should prioritize consistent measurement approaches and explore long-term impacts.

Are you having trouble in saying this stuff? It's really quite easy for me. I just look in my mirror and see what I say, and then I just say what I see. (Seuss, 1979) Introduction Our review of research in the basic areas of language acquisition has led us to several conclusions regarding our fundamental question: how does a child acquire language? They lead us to overturn several common myths about language acquisition. While they do not directly provide us with a full theory of language acquisition, they allow us to lay the foundations for a future theory, one which can link both linguistic and developmental approaches. In this chapter, we will first summarize fundamental generalizations that emerge from the research we have reviewed; next, we will identify remaining open questions and sketch a framework which we consider promising for future research. Conclusions (A) We have seen that the course of language acquisition begins at birth, if not before, and proceeds continuously through the first few years of life. There is no “prelinguistic” stage. Although language acquisition is commonly thought to begin with children's first produced words, we have seen that the first words are the culmination of previous, complex language development. Contrary to a common assumption, words are not the “building blocks” of language acquisition, but develop in parallel to acquisition of the formal system of language, and in part as a result of this. […]

Although children’s acquisition of a first, or native language is a matter of perennial interest, no consensus has emerged in English-language scholarship about how to refer to what it is that children do (or what it is that happens) in the first few years of life, when children move from non-talking neonates to full participation in a human speech community. Some have called this phenomenon ‘child language learning’; others ‘first language acquisition’; others ‘the development of language’; and still others, ‘the emergence of speech’. This paper compares a range of expressions used in the late 1800s (by Whitney, Pollack, and Lukens, among others) to discuss child language acquisition, to the terminology employed by present-day generativist and nongenerativist scholars. In both periods, writers’ word choice reveals not only their own conceptualization but also how they position themselves vis-à-vis competing ways of conceptualizing how children learn language.

Should All Deaf Children Learn Sign Language?

Dispersal of Sparrowhawks between Birthplace and Breeding Place