Language Functions and Brain Organization

Language Functions and Brain Organization explores the question of how language is represented in the human brain. The discussions are organized around the following themes: whether language is a mental organ or a mental complex; the brain base for language; the requirements of a developmental theory of lateralization; and whether brain lateralization is a single construct. Comprised of 15 chapters, this volume begins with an assessment of the semantic and syntactic aspects of aphasic deficits and how these components can be selectively disrupted by focal brain damage, followed by a review of evidence for hemispheric asymmetries in processing phonological information. The reader is then introduced to pragmatic aspects of communication; the right hemisphere's contribution to language; and right-left asymmetries in the cerebral cortex and their implications for functional asymmetries. Subsequent chapters focus on left-hemisphere language specialization from the perspective of motor and perceptual functions; evidence for hemisphere asymmetry for language functioning in the thalamus; some difficulties in building a brain theory for visual experience; speech lateralization in infancy; and the relationship between cerebral functional asymmetries, maturation rate, and cognitive skills through the mediation of sex chromosomes. The book also considers language dysfunction in dementia and its connection to brain functioning, along with the variations produced in cases of bilingualism and the factors that may be critical for this issue. This monograph is addressed to researchers and students of the neuropsychology of language, whether they call themselves psychologists, neuropsychologists, neurologists, or linguists.

Table of Contents:
Contributors Preface I. Language as a Mental Organ or a Mental Complex Introduction Language as a Set of Neuropsychological Skills References 1. Language Functions: Syntax and Semantics Introduction Semantic Deficits in Aphasia Syntactic Deficits in Aphasia Conclusion References 2. Hemisphere Processing of Phonological Information Introduction Dichotic Listening with Brain-Damaged Populations Electrophysiological Correlates of Speech Perception Summary References 3. Pragmatic Aspects of Communication in Brain-Damaged Patients Introduction Vehicles of Communication Pragmatic Structures Other Linguistic Forms Conclusion References 4. The Right Hemisphere's Contribution to Language: A Review of the Evidence from Brain-Damaged Subjects Introduction Lesion Studies Commissurotomy Regional Cerebral Blood Flow Neurosurgical Studies Sodium Amytal (Wada Test) 109 Conclusion References II. What Should Be the Brain Base for Language? Introduction References 5. Bumps on the Brain: Right-Left Asymmetry as a Key to Functional Lateralization Introduction Nature of Hemisphere Specialization Unresolved Issues Limitations of Neurocognitive Methods Neuroanatomical Asymmetry Problems in Relating Planum Asymmetry and Functional Lateralization Asymmetries in Vivo and Functional Lateralization Planum Asymmetry and Speech Lateralization Implications of a Neuroanatomical Substrate of Cerebral Dominance References 6. Motor and Perceptual Functions of the Left Hemisphere and Their Interaction Introduction Auditory Perceptual Functions of the Left Hemisphere Evidence for Lateralized Manual Motor Control Evidence for Lateralized Oral Movement Control Traditional Localization of Oral Motor Control Perceptual Studies Production Studies Neurophysiological Studies Suggesting an Overlap in Perception and Production Behavioral Studies Theories Regarding the Motor-Perceptual Link Summary and Conclusion References 7. Thalamic Mechanisms in Language and Memory Introduction Anatomical Review Alterations in Language and Memory After Thalamic Lesions: Evidence from Spontaneously Occurring Lesions Language Changes Associated with Stereotaxic Thalamic Lesions The Role of the Left Thalamus in Language: Evidence from Electrical Stimulation The Role of Thalamic Motor Functions in Speech Summary Other Subcortical Areas References 8. The Placement of Experience in the Brain Introduction Logical Problems of Localizing Experience The Nature of Place Methodological Problems of Localization The Nature of Qualia References III. On the Requirements of a Developmental Theory of Lateralization Confusing Maturation with Development Neurophysiological Changes Psychological Changes Changes in Cerebral Asymmetries with Age Conclusions References 9. Cerebral Asymmetries for Speech in Infancy Introduction Evidence for Speech Lateralization in Infancy What Is Lateralized in Infancy? Implications for a Developmental Model of Lateralization References 10. Hemispheric Specialization and Integration in Child Development Introduction The Input-Output Problem and the Two-Compartment Black Box Development as a Nonlinear Sequence The Study of the Developing Brain: The Soviet Electrophysiological Approach Conclusions References 11. Relationships Among Brain Organization, Maturation Rate, and the Development of Verbal and Nonverbal Ability Introduction Sex-Related Biological Factors and Intellectual Ability Growth, the X Chromosome, and Cerebral Organization Conclusion References 12. Language and Brain Dysfunction in Dementia Introduction Cortical and Subcortical Dementias Language Form and Semantics Conclusion: Language and Neuropsychological Behavior References IV. Is Brain Lateralization a Single Construct? Introduction References 13. Cerebral Specialization in Deaf Individuals Introduction Cerebral Specialization in Deaf Individuals: Overview Speculations on the Cerebral Lateralization of Sign Language Clinical Evidence Concerning the Cerebral Lateralization of Sign Language Experimental Evidence Concerning Cerebral Specialization in Deaf Individuals: Tachistoscopic Studies General Discussion References 14. Bilingualism and Brain Lateralization Introduction Clinical Evidence Experimental Evidence Language-Specific Factors Language-Acquisitional Factors Age of Second Language Acquisition Discussion References 15. Individual Differences in Hemispheric Representation of Language Introduction Differences in Brain Morphology Early Experiences and Psycholinguistic Strategy The Problem of Task Demands Evidence for the Importance of Hemisphericity Handedness and Language Lateralization Sex Differences and Neurolinguistic Organization Getting a Measure of Intrasubject Variance Coping with Individual Differences in Neurolinguistic Organization References Index