Sensitive Q1 Periods for Language and Recovery From Stroke: Conceptual and Practical Parallels ABSTRACT: In this review, we consider the literature on sensitive periods for language acquisition from the perspective of the stroke recovery literature treated in this Special Issue. Conceptually, the two areas of study are linked in a number of ways. For example, the fact that learning itself can set the stage for future failures to learn (in second language learning) or to remediate (as described in constraint therapy) is an important insight in both areas, as is the increasing awareness that limits on learning can be overcome by creating the appropriate environmental context. Similar practical issues, such as distinguishing native-like language acquisition or recovery of function from compensatory mechanisms, arise in both areas as well. ß 2011 Wiley Periodicals, Inc. Dev Psychobiol 9999: 1–11, 2012. Keywords: sensitive periods; language acquisition; speech disorders; stroke recov- ery; motor system INTRODUCTION Q2 The literature on sensitive periods for language provides a unique lens through which to view the rela- tionship between adult recovery from stroke and devel- opmental changes in plasticity. Lenneberg’s (1967) systematic treatment of the literature on differential re- covery from stroke over the course of development ar- guably marks the beginning of modern research on sensitive periods for language. Research on the brain basis of language is very much grounded in aphasiology; the classical view of language function depending on interactions between ‘‘Broca’s area’’ and ‘‘Wernicke’s area’’ (e.g., Geschwind, 1970) are still rel- evant despite concerns that they are at best approximate (and at worst misleading) at both the level of anatomy (Dronkers, Wilkins, Van Valin, Redfern, & Jaeger, 2004) and function (see Poeppel & Hickok, 2004, for review). That the simplest classical model already involves a network that links perception and production hints at the complexity of understanding structure– function relationships in language. This complexity emerges whether we consider language in terms of lin- guistic levels of description (lexical, grammatical, pho- nological) or in terms of its relationship to more basic functions (linking perceptual and motor systems). Thus, key concepts that emerge throughout this spe- cial issue resonate deeply with the literature on sensi- tive periods for language. For example, approaches to understanding sensitive periods for language that em- phasize the role of learning itself on setting limits for plasticity (the ‘‘paradox of success,’’ reviewed in Seid- enberg & Zevin, 2006) are clearly related to learning- based approaches to remediation such as constraint induced therapy (Taub) and the IMITATE framework (Small). Similarly, there has been an increased focus in recent years on understanding both sequelae and recov- ery from brain damage in terms of the function of a larger network (Corbetta, Kolb), and an organism’s re- organization of behavior in response to changes in the ‘‘internal milieu’’ (Small) in contrast to defining fixed, DEV-11-142(20626) Developmental Psychobiology Jason D. Zevin Hia Datta Jeremy I. Skipper Sackler Institute for Developmental Psychobiology, Weill Cornell Medical College, 1300 York Ave., Box 140, New York, New York 10065 E-mail: jdz2001@med.cornell.edu Received 2 November 2011; Accepted 2 November 2011 Correspondence to: Jason D. Zevin Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/dev.20626 ß 2011 Wiley Periodicals, Inc.