Neuropsychology of Left-Handedness

List of Contributors

Preface

I Wence Sinistrality?

1 Left-Handedness: Early Theories, Facts, and Fancies

Introduction

How Many Left-Handers?

Early Theories

Heredity

Ambidextral Culture

Left-Handedness as Pathological

Studies of Animals

Conclusion

References

2 Neuroanatomical Asymmetry in Left-Handers: A Review and Implications for Functional Asymmetry

Introduction

Hemisphere Functional Asymmetry

Neuroanatomical Asymmetry

Patterns of Cognitive Skills and Neuroanatomical Asymmetry

Gender and Neuroanatomical Asymmetry

Summary

References

3 The Sinistral Blastocyst: An Embryologic Perspective on the Development of Brain-Function Asymmetries

4 Left-Handedness in Twins: Implications for the Mechanisms Underlying Cerebral Asymmetry of Function

Introduction

The Incidence of Sinistrality among Twins

Factors Responsible for Elevating the Incidence of Sinistrality among Twins

The Relationship of Handedness, Cerebral Organization, and Cognitive Abilities in Twins

Conclusions

References

5 Is Left-Handedness Genetically Determined?

Introduction

Annett/s Model

A Nongenetic Approach

Conclusions

References

6 A Model for the Ontogeny of Cerebral Organization in Non-Right-Handers

Introduction

Hypotheses about the Brain Basis of Cerebral Specialization

Brain Stem Activity and Cerebral Asymmetry

The Selective Activation Model of Cerebral Lateralization

References

II Cerebral Variation: The Most Consistent Sinistral Atribute

7 Incidence of Aphasia in Lefl-Handers: A Test of Some Hypothetical Models of Cerebral Speech Organization

Introduction

Method

Results

Discussion

References

8 Individual Differences in Psychoneurological Organization

Introduction

Origins of Lateral Asymmetry

Behavioral Indices of Cerebral Laterality

Sex-Related Differences in Cerebral Organization

The Population Variance in Hemispheric Lateralization

Predictions regarding the Cognitive Covariates of Cerebral Organization

Summary

References

9 Handedness and Individual Differences in Hemispheric Activation

Introduction

Hemispheric Activation: The Concept and Its Operationalization

The Effect of Handedness, Sex, and Eye Dominance on Hemispheric Activation

Summary

References

10 Two Hands, Two Brains, Two Sexes

Introduction

Right versus Left-Handed Differences

Left-Handed versus "Ambi-Handed" Differences

Inverted versus Noninverted Hand Posture Differences

References

III Sinistral Abilities

11 Handedness and Memory for Tonal Pitch

Introduction

Experiment 1

Experiment 2

Discussion

References

12 Handedness in Artists

Introduction

Method

Results

Discussion

References

13 Cognitive Deficit and Left-Handedness: A Cautionary Note

Method

Results

Discussion

References

14 Age-Related Changes in Cognitive Abilities and Hemispheric Specialization

Introduction

Hemispheric Development

Cognitive Abilities

Implications of Cognitive Differences

Age-Associated Changes in Cognitive Abilities and Hemispheric Specialization

References

15 Which Hand Is the "Eye" of the Blind?—A New Look at an Old Question

Introduction

Hand Asymmetries in Braille Reading: Early Studies

Braille Reading and Right-Hemisphere Functions

Experiment 1: Blind Subjects

Hand Asymmetries in Sighted Subjects

Experiment 2: Sighted Subjects, Massed Left-Right Trials

Experiment 3: Sighted Subjects, Alternating Left-Right Trials

Experiment 4: Left-Handers, Massed Left-Right Trials

Experiment 5: Left-Handers: Alternating Left-Right Trials

Summary and Conclusions

References

16 Tactile Learning, Handedness, and Reading Disability

Introduction

Mechanical Tactile Stimulation

Experiment 1: Interhemispheric Transfer from the Chest Area to the Hands

Experiment 2: Interhemispheric Transfer from the Nonpreferred to the Preferred Hand

Visual Memory

Discussion

Summary

Acknowledgments

References

Subject Index