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Journal ArticleDOI

Discourse Deficits Following Right Hemisphere Damage in Deaf Signers

01 Feb 1999-Brain and Language (Academic Press)-Vol. 66, Iss: 2, pp 233-248

TL;DR: It is concluded that, as in the hearing population, discourse functions involve the right hemisphere; that distinct discourse functions can be dissociated from one another in ASL; and that brain organization for linguistic spatial devices is driven by its functional role in language processing, rather than by its surface, spatial characteristics.

AbstractPrevious findings have demonstrated that hemispheric organization in deaf users of American Sign Language (ASL) parallels that of the hearing population, with the left hemisphere showing dominance for grammatical linguistic functions and the right hemisphere showing specialization for non-linguistic spatial functions. The present study addresses two further questions: first, do extra -grammatical discourse functions in deaf signers show the same right-hemisphere dominance observed for discourse functions in hearing subjects; and second, do discourse functions in ASL that employ spatial relations depend upon more general intact spatial cognitive abilities? We report findings from two right-hemisphere damaged deaf signers, both of whom show disruption of discourse functions in absence of any disruption of grammatical functions. The exact nature of the disruption differs for the two subjects, however. Subject AR shows difficulty in maintaining topical coherence, while SJ shows difficulty in employing spatial discourse devices. Further, the two subjects are equally impaired on non-linguistic spatial tasks, indicating that spared spatial discourse functions can occur even when more general spatial cognition is disrupted. We conclude that, as in the hearing population, discourse functions involve the right hemisphere; that distinct discourse functions can be dissociated from one another in ASL; and that brain organization for linguistic spatial devices is driven by its functional role in language processing, rather than by its surface, spatial characteristics.

Topics: Spatial cognition (56%), Spatial ability (54%), American Sign Language (53%), Population (52%), Sign language (51%)

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Citations
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Journal ArticleDOI
Abstract: Most of our knowledge about the neurobiological bases of language comes from studies of spoken languages. By studying signed languages, we can determine whether what we have learnt so far is characteristic of language per se or whether it is specific to languages that are spoken and heard. Overwhelmingly, lesion and neuroimaging studies indicate that the neural systems supporting signed and spoken language are very similar: both involve a predominantly left-lateralised perisylvian network. Recent studies have also highlighted processing differences between languages in these different modalities. These studies provide rich insights into language and communication processes in deaf and hearing people.

210 citations


Journal ArticleDOI
TL;DR: It is demonstrated that the RH angular gyrus is active during ASL processing only in native signers (hearing, ASL-English bilinguals) but not in those who acquired ASL after puberty ( hearing, native English speakers).
Abstract: Signed languages such as American Sign Language (ASL) are natural languages that are formally similar to spoken languages, and thus present an opportunity to examine the effects of language structure and modality on the neural organization for language. Native learners of spoken languages show predominantly left-lateralized patterns of neural activation for language processing, whereas native learners of ASL show extensive right hemisphere (RH) and LH activation. We demonstrate that the RH angular gyrus is active during ASL processing only in native signers (hearing, ASL-English bilinguals) but not in those who acquired ASL after puberty (hearing, native English speakers). This is the first demonstration of a 'sensitive' or 'critical' period for language in an RH structure. This has implications for language acquisition and for understanding age-related changes in neuroplasticity more generally.

188 citations


Journal ArticleDOI
01 Oct 2001-Brain
TL;DR: Results indicate that anterior and posterior areas may play distinct roles in early and late stages of language production, and suggest a novel model for lateralization of cerebral activity during the generation of discourse.
Abstract: In order to identify brain regions that play an essential role in the production of discourse, H2 15O-PET scans were acquired during spontaneous generation of autobiographical narratives in English and in American Sign Language in hearing subjects who were native users of both. We compared languages that differ maximally in their mode of expression yet share the same core linguistic properties in order to differentiate the stages of discourse production: differences between the languages should reflect later, modality-dependent stages of phonological encoding and articulation; congruencies are more likely to reveal the anatomy of earlier modality-independent stages of conceptualization and lexical access. Common activations were detected in a widespread array of regions; left hemisphere language areas classically related to speech were also robustly activated during sign production, but the common neural architecture extended beyond the classical language areas and included extrasylvian regions in both right and left hemispheres. Furthermore, posterior perisylvian and basal temporal regions appear to play an integral role in spontaneous self-generated formulation and production of language, even in the absence of exteroceptive stimuli. Results additionally indicate that anterior and posterior areas may play distinct roles in early and late stages of language production, and suggest a novel model for lateralization of cerebral activity during the generation of discourse: progression from the early stages of lexical access to later stages of articulatory-motor encoding may constitute a progression from bilateral to left-lateralized activation. This pattern is not predicted by the standard Wernicke-Geschwind model, and may become apparent when language is produced in an ecologically valid context.

158 citations


Cites background from "Discourse Deficits Following Right ..."

  • ...More recently, neuropsychological, electrophysiological and neuroimaging studies in neurologically intact subjects, and more detailed clinical evaluation of aphasics, suggest that the right hemisphere plays a significant role in the processing of both signed and spoken language particularly in the more complex, pragmatic features of each (Frederiksen et al., 1990; Bloom et al., 1992; Neville et al., 1998; Hickok et al., 1999)....

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  • ...…clinical evaluation of aphasics, suggest that the right hemisphere plays a significant role in the processing of both signed and spoken language particularly in the more complex, pragmatic features of each (Frederiksen et al., 1990; Bloom et al., 1992; Neville et al., 1998; Hickok et al., 1999)....

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Book
Barbara Lust1
21 Sep 2006
TL;DR: This chapter focuses on the development of an integrated theory of language acquisition through the acquisition of phonology, syntax, semantics and semantics in the context of a young child.
Abstract: The remarkable way in which young children acquire language has long fascinated linguists and developmental psychologists alike. Language is a skill that we have essentially mastered by the age of three, and with incredible ease and speed, despite the complexity of the task. This accessible textbook introduces the field of child language acquisition, exploring language development from birth. Setting out the key theoretical debates, it considers questions such as what characteristics of the human mind make it possible to acquire language; how far acquisition is biologically programmed and how far it is influenced by our environment; what makes second language learning (in adulthood) different from first language acquisition; and whether the specific stages in language development are universal across languages. Clear and comprehensive, it is set to become a key text for all courses in child language acquisition, within linguistics, developmental psychology and cognitive science.

148 citations


01 Feb 1975

106 citations


References
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Book
01 Jan 1979
Abstract: Introduction PART I: The Two Faces of Sign 1. Iconicity in Signs and Signing 2. Properties of Symbols in a Silent Language 3. Historical Change: From Iconic to Arbitrary PART II: The Structure of the Sign 4. Remembering without Words: Manual Memory 5. Slips of the Hands 6. A Comparison of Chinese and American Signs 7. A Feature Analysis of Handshapes 8. The Rate of Speaking and Signing PART III: Grammatical Processes 9. On the Creation of New Lexical Items by Compounding 10. Linguistic Expression of Category Levels 11. Aspectual Modulations on Adjectival Predicates 12. The Structured Use of Space and Movement: Morphological Processes PART IV: The Heightened Use of Language 13. Wit and Plays on Signs 14. Poetry and Song in a Language without Sound Appendix A: Notation Appendix B: Conventions Employed in Illustrations Notes References Index

1,563 citations


"Discourse Deficits Following Right ..." refers background in this paper

  • ...The sublexical units from which signs are composed are often articulated simultaneously rather than sequentially, and spatial location contrasts certain pairs of minimally different signs (Klima & Bellugi, 1979, Chap....

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  • ...2); morphological inflections of signs generally alter the movement path of the sign, rather than concatenating morphemic units across time (Klima & Bellugi, 1979, Chap....

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  • ...At the morphological level, ASL has grammatical markers that serve as inflectional and derivational morphemes; these are regular changes in form across classes of lexical items associated with systematic changes in meaning (Klima & Bellugi, 1979)....

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Journal ArticleDOI

1,385 citations


Book
01 Jan 1987
Abstract: What the Hands Reveal About the Brain provides dramatic evidence that language is not limited to hearing and speech, that there are primary linguistic systems passed down from one generation of deaf people to the next, which have been forged into antonomous languages and are not derived front spoken languages.

578 citations


"Discourse Deficits Following Right ..." refers background in this paper

  • ...…tasks, while the right lesioned signers exhibit marked deficits involving left neglect, loss of perspective, loss of the overall configuration of the figure, etc. (Hickok et al., 1995; Hickok et al., 1996; Poizner & Kegl, 1993; Bellugi, Poizner, & Klima, 1989, 1990; Poizner et al., 1987)....

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  • ...But while RHD signers do not present with aphasia for sign at the lexical, morphological, or syntactic level, they do show significant deficits in nonlinguistic visuospatial processing (Bellugi & Hickok, 1995; Hickok et al., 1996; Poizner et al., 1987)....

    [...]

  • ...The RHD deaf signers are much like the controls, while the LHD deaf signers show a range of different sign language aphasias (Poizner et al., 1987)....

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01 Jan 1993

419 citations


Book
01 Aug 1996
TL;DR: General principles aphasia and other dominant hemisphere Syndromes disorders of perception, attention and awareness frontal, collosal and subcortical syndromes memory and amnesia delirium and dementia epilepsy and related issues emotional disorders neurobehavioural disorders in children.
Abstract: General principles aphasia and other dominant hemisphere syndromes disorders of perception, attention and awareness frontal, collosal and subcortical syndromes memory and amnesia delirium and dementia epilepsy and related issues emotional disorders neurobehavioural disorders in children .

390 citations