HIGHER CORTICAL

FUNCTIONS IN MAN

PREFACES TO THE ENGLISH EDITION BY

HANS-LUKAS TEUBER

and KARL H. PRIBRAM

AUTHORIZED TRANSLATION FROM THE RUSSIAN

by BASIL HAIGH

HIGHER CORTICAL

FUNCTI.ONS INMAN

Second Edition, Revised and Expanded

ALEKSANDR ROMANOVICH LURIA

Basic Books, Inc., Publishers New York

CONSULTANTS BUREAU New York

The original Russian text was published by

Moscow University Press in 1962

Library of Congress Catalog Card Number: 77-20421 ISBN-13: 978-1-4m5-8s1h"7

DOl: 10.100']19711-1-4615-1\5']9-4

Copyright © 1966, 1980 Consultants Bureau Enterprises, Inc.,

and Basic Books, Inc.

Softcover reprint of the hardcover 2nd. edition 1980

All rights reserved. No part of this

publication may he reproduced in any form without written

permission from the publishers. Manufactured in the United

States of America.

10 9 8 7 6 5 4 3 2 I

Drawing by Leonardo da Vinci illustrating the Renaissance view of the structure of the brain and of the three cerebral ventricles

Contents

Preface by Hans - Leukas Teuber Preface by Karl H. Pribram Foreword

xi xv

XVll

xix xxi

Foreword to the Second Edition Foreword to the Second American Edition

I THE HIGHER MENTAL FUNCTIONS AND THEIR

ORGANIZATION IN THE BRAIN

1. The Problem of Localization of Functions in the Cerebral Cortex 3 A. Psychomorphological Concepts and Their Crisis-

A Historical Survey 3 B. Re-examination of the Concept of Function and of the

Principles of Its Localization 21

C. The Higher Mental Functions in Man 28 2. Modern Data on the Structural Organization of the

Cerebral Cortex 37 A. Original Conceptions 37 B. Structural Organization of the Posterior Cortical Divisions 42 C. Structural Organization of the Anterior Cortical Divisions 51 D. Progressive Differentiation of the Cortical Regions and

Fields in· the Course of Phylogenesis and Ontogenesis 56 E. Structural Organization and Connections of the Mediobasal

.Cortical Divisions 63 F. Functional Properties of Cortical Neurons 67

3. Disturbances of Higher Mental Functions in the Presence of Local Brain Lesions 78

vi

CONTENTS

II DISTURBANCES OF THE HIGHER CORTICAL FUNCTIONS

IN THE PRESENCE OF LOCAL BRAIN LESIONS

1. Some Functional Investigative Problems 89 A. Principal Forms of Disturbance of the Higher Cortical

Functions Resulting from Local Brain Lesions 89 B. The Problem of the Dominant Hemisphere 95 C. General Cerebral Components in Cases of Local Brain

Lesions 104

2. Disturbances of Higher Cortical Functions with Lesions of the Temporal Region 107

A. Historical Survey 108 B. The Auditory Analyzer and the Structure of the Auditory

Cortex 109 C. Language Sounds and the Hearing of Speech 113 D. Disturbances of Higher Cortical Functions with Lesions of

the Cortical Nucleus of the Auditory Analyzer. Acoustic Agnosia and Sensory Aphasia 117

E. Disturbances of Higher Cortical Functions with Lesions of the Middle Segments of the Temporal Region. Acoustic-Mnestic Aphasia 128

F. Disturbances of Intellectual Processes with Temporal Lesions I!S6

G. Disturbances of Psychological Processes in Lesions of the Medial Zones of the Temporal Regions 140

3. Disturbances of Higher Cortical Functions with Lesions of the Occipital and Occipitoparietal Regions 146 A. Historical Survey 147 B. The Visual Analyzer and the Structure of the Visual Cortex 149 C. Disturbed Object Perception with Lesions of the Visual

Cortex and Concurrent Agnosia 157 D. Disturbed Tactile Perception and Tactile Agnosia 168 E. Spatial Disorientation and Constructive Apractagnosia 171 F. Disturbed Logical-Grammatical Operations and Semantic

Aphasia 177 G. Disturbances of Arithmetical Operations and the Syn-

drome of Acalculia 182 H. Disturbances of Intellectual Processes 186

4. Disturbances of Higher Cortical Functions with Lesions of the Sensorimotor Regions 189 A. Historical Survey 189 B. The Motor Analyzer and the Structure of the Sensorimotor

Region 196

Vll

CONTENTS

5.

6.

7.

C. Disturbances of the Afferent Basis of Voluntary Movement. Afferent (Kinesthetic) Apraxia

D. Disturbances of the Kinesthetic Basis of Speech. Afferent (Kinesthetic) Motor Aphasia

E. Disturbances of Motor Functions with Lesions of the Pre-motor Region

F. Disturbances of the Kinetic Structure of Speech. Efferent (Kinetic) Motor Aphasia

G. Frontal "Dynamic" Aphasia H. Disturbances of Intellectual Processes with Lesions of the

Premo tor Region Disturbances of Higher Cortical Functions with

Lesions of the Frontal Region

A. Historical Survey B. Sfructure and Functions C. The Frontal Lobes and Regulation of States of Activity D. The Frontal Lobes and Regulation of Movements and

Actions E. Gnostic Disturbances F. Mnestic Disturbances G. Intellectual Disturbances H. Principal Variants of the Frontal Syndrome Disturbances of Higher Cortical Functions in

Deep Brain Lesions

On Function Interaction Between the Hemispheres

III METHODS OF INVESTIGATING THE HIGHER CORTICAL

FUNCTIONS IN LOCAL BRAIN LESIONS

(SYNDROME ANALYSIS)

202

207

215

226 237

241

246 248 257 263

285 327 338 345 360

366 374

1. Objectives of Neuropsychological Investigation of

Higher Cortical Functions in the Presence of

Local Brain Lesions 387 2. The Preliminary Conversation 398 3. Investigation of Motor Functions 414

A. Preliminary Remarks 414 B. Investigation of the Motor Functions of the Hands 415 C. Investigation of Oral Praxis 425 D. Investigation of Complex Forms of Organization of Move-

ments and Actions 428

viii

CONTENTS

4 Investigation of Acoustico-Motor Coordination 436 A. Preliminary Remarks 486 B. Investigation of the Perception and the Reproduction of

Pitch Relationships 486 C. Investigation of the Perception and the Reproduction of

Rhythmic Structures 489 5. Investigation of the Higher Cutaneous and

Kinesthetic Functions 444 A. Preliminary Remarks 444 B. Investigation of Tactile (Cutaneous) Sensation 444 C. Investigation of Deep (Kinesthetic) Sensation 447 D. Investigation of the Higher Tactile Functions and

Stereognosis 449 6. Investigation of the Higher Visual Functions 45 1

A. Preliminary Remarks 451 B. Investigation of the Visual Perception of Objects and

Pictures 454 C. Investigation of Spatial Orientation 461 D. Investigation of Intellectual Operations in Space 464

7. Investigation of Mnestic Processes 469 A. Preliminary Remarks 469 B. Investigation of the Direct Impression of Traces 470

C. Investigation of the Learning Process 475 D. The Role of Interference in Disturbances of Mnestic

Processes 478 E. Investigation of Logical Memorizing 488

8. Investigation of Speech Functions. Receptive Speech 486 A. Preliminary Remarks 486 B. Investigation of Phonemic Hearing 490 C. Investigation of Word Comprehension 498 D. Investigation of the Understanding of Simple Sentences 497 E. Investigation of the Understanding of Logical-Grammatical

Structures 499 9. Investigation of Speech Functions. Expressive Speech 506

A. Preliminary Remarks 506 B. Investigation of the Articulation of Speech Sounds 507 C. Investigation of Reflected (Repetitive) Speech 509 D. Investigation of the Nominative Function of Speech 513 E. Investigation of Narrative Speech 518

10. Investigation of Writing and Reading 528 A. Preliminary Remarks 528 B. Investigation of the Phonetic Analysis and Synthesis of

Words 538 C. Investigation of Writing 587 D. Investigation of Reading 543

ix

CONTENTS

11. Investigation of Arithmetical Skill A. Preliminary Remarks B. Investigation of the Comprehension of Number Structure C. Investigation of Arithmetical Operations

12. Investigation of Intellectual Processes A. Preliminary Remarks B. Investigation of the Understanding of Thematic Pictures

and Texts C. Investigation of Concept Formation D. Investigation of Discursive Intellectual Activity

Conclusion Bibliography

Russian Non-Russian

Subject Index Author Index

553 5511 554 557 562 562

565 5711 580

586 589

589 604 626 63 1

Preface

This full-length translation of Professor Luria's book introduces to the English­speaking world a major document in neuropsychology, summarizing Professor Luria's earlier contributions to that area for nearly a third of a century. It is a monumental contribution. Nothing of this scope exists in the Western literature of this field, with the possible exception of Ajuriaguerra and Hecaen's book (in French) on the cerebral cortex. Professor Luria's book thus marks a further and decisive step toward the eventual coalescence of neurology and psychology, a goal to which only a few laboratories in the East and West have been devoted over the last decades.

The book is unique in its organization. The first half deals with observations and interpretations concerning the major syndromes of man's left cerebral hemisphere: those grievous distortions of higher functions traditionally described as aphasia, agnosia, and apraxia. There is also a detailed and brilliant analysis of the syndrome of massive frontal-lobe involvement. The entire second half of the book is given over to a painstaking description of Professor Luria's tests, many of them introduced by himself, and set out in such detail that anyone could repeat them and thus verify Professor Luria's interpretations.

The two halves of the book are equally challenging and original. In the first, more tbeoretical, section, Professor Luria gives an account of the major syndromes in terms that reject with the same force the traditionallocalizationist view-the notion of discrete centers for different aspects of language, of calculation or writing-and the opposite view of holistic function of the cerebral hemisphere, a view clearly incompatible with clinical and experi­mental fact. In a similar way, Professor Luria's re-analysis of agnosia and apraxia reveals inadequacies of these clinical shorthand expressions; he points out that more elementary sensory and motor changes shade into the allegedly isolated aspects of distorted "higher" function, whether of recognition or skilled movement. As a result of this balance~ approach, a further traditional distinction falls by the wayside-the traditional opposition in the description of aphasia between the "instrumental" and "noetic" views, that is, between

xi

PBEFACI!!

those who believe that language is merely disturbed as a tool, with intel­ligence essentially intact, and those who believe that the trouble with language is simply one of several manifestations of an underlying change of intelligence.

The theoretical position adopted by Professor Luria himself in the face of these incredibly perplexing syndromes is most intriguing. He invokes cerebral reflexes as the basic elements of behavior. Yet careful reading reveals a remarkable restraint in the postulation of specific interruption of normal connections between different brain regions as the origin of major syndromes. In point of fact, he rejects the concept of conduction aphasia, preferring instead a carefully descriptive approach. Yet there is boldness too, as Professor Pribram stresses in his companion preface to this remarkable book: Professor Luria invokes again and again a principle of re-afference, in the tradition of Orbeli and Anokhin, and-one might add-of von Holst, modifying tra­ditional reflex views and emphasizing the all-pervasive influence of self­produced stimulation {such as proprioceptive feedback} which the organism must compare continuously with its intended output in order to assess the success of its own movements. This sort of approach to sensorimotor co­ordination requires a new way of looking at the major brain syndromes in man. It becomes particularly fruitful in dealing with the baffling changes in human behavior after lesions of the frontal lobes, an area of furious contro­versy where Professor Luria reaches conclusions {he claims there is an essential disturbance of "intention"} which are identical with those reached in our own laboratory on the basis of quite different clinical and experimental data.

The second half of the book with its rich descriptions of tests will be at least as influential as the first. Here one is struck primarily by the disarming simplicity of methods, nearly all suitable for bedside conditions, few requiring more than the examiner's voice, a few blocks, or paper and pencil. If one has had the privilege of observing Professor Luria and his staff in action at the Burdenko Institute in Moscow, one doubly appreciates the choice of his tasks, because he deals with large numbers of brain tumor cases, week after week; his assessment of these cases-the "neuropsychological" report-goes onto their clinical charts, together with other diagnostic techniques such as X-ray evaluations and electroencephalograms.

Where the situation demands it, Professor Luria is quite willing to employ more elaborate experimental techniques, such as the recording of eye move­ments, especially in cases of frontal-lobe involvement. Yet the emphasis remains on bedside tests, and a great many of them. It is here that the Western reader will be impressed by a difference in approach: neuropsychological laboratories in the West tend to be more quantitative.

The contrast is instructive, since one of the liberating effects of scientific exchange is to make one look at one's own work in a new and different way, as if one were permitted to look at it for a moment from the outside. Quantifi­cation is a major strength of the British and American tradition in psychology. If a book like Professor Luria's had been written here, it would teem with

xii

PREFACE

means and standard deviations, not to speak of analyses of variance and covariance. Yet the sobering fact is that most of Professor Luria's conclusions would not be changed if he had chosen to use these refinements. His own enormous clinical experience and his intuitive sense for what are reasonable interpretations are playing for him the role of large-sample statistics.

But there is a further and more important aspect to the difference in style of work: Much analysis in current neuropsychology in the United States (though much less in England and France) makes large-scale use of standard tests of intelligence, often at the expense of more versatile, qualitative tasks of the kind employed by Professor Luria. Here is a serious danger. By relying on routine psychometrics, one often loses crucial opportunities for the analysis of altered performance in the presence of brain lesions. Professor Luria's restraint in the use of psychometrics seems to me a major strength in his approach.

One of the most serious indictments of such psychometric tests comes from studies that permitted direct comparison of intelligence test scores obtained before, and again, in the same subjects, after a penetrating brain injury. In our own experience with such comparisons, two-thirds of an unselected group of brain-injured men have improved their scores from test to retest, even though the brain injury had intervened. Many of these patients increased their scores just as much as their controls. Yet most of the patients would have done poorly on a number of Professor Luria's informal, qualitative tasks, which are directly geared to the detection of specific change after cerebral lesions, while routine tests of intelligence are not.

The ingenious and abundant "little" tests employed by Professor Luria will undoubtedly find their uses here, and norms will be obtained in a number of laboratories. It will be of particular interest to see how his interpretations will hold up on cross-validation to other populations of patients, particularly those with selective removals of cortex for relief of epilepsy, or to those who have penetrating trauma in the absence of other complicating factors. Principal reliance on tumor cases, as in Professor Luria's work, entails certain risks of which Professor Luria is quite aware. His patients, on the whole, are more gravely ill than those studied in the neuropsychological program of, say, the Montreal Neurological Institute, where behavioral analyses are concentrated on cases of selective cortical removals for treatment of epilepsy, or in our own laboratory, with its major emphasis on the studies of late aftereffects of penetrating missile wounds of the brain. The more serious involvement in brain tumor cases is particularly apparent in patients with frontal-lobe tumors, since these tumors often grow undetected for considerable periods, as compared with those in other regions of the brain, where specific symptoms are more rapidly evident.

Yet Professor Luria makes the point that certain essential local symptoms are often brought out best against the background of more general changes in the brain, those due to pressure, vascular disturbance, or diffuse toxic effects

xiii

PB£FACI!!

The touchstone will be cross-validation and, as regards frontal syndromes, the agreement between his conclusion and ours is simply astonishing, considering the vast difference in patients and in methods.

In this connection, a last word of caution, not so much to the physicians who will read and use this book, but to the psychologists, who will receive it with equal eagerness: Professor Luria's techniques, in their intent and in their application, are extensions of the classical neurological examination-=-major extensions, to be sure, but extensions nevertheless. This means that we must use his techniques just as he does-in conjunction with the standard neurologic examination, and not in its stead. In this way, the maximal benefit will accrue to the diagnosis of the patient's condition, and to an understanding of the roots of his difficulties. For it should be remembered that the central task of neuropsychology is always twofold: to help the patient by understanding his disease, and to understand the disease, in turn, as ah experiment of nature, an experiment that, if properly used, may provide us with essential insights into the physiologic basis of normal function. In that sense, any contribution to neuropsychology attempts to tell us how the brain does work-by carefully observing how it sometimes does not.

Here then is the book, written by a master in his chosen field. Its translation marks a further step in the mutual recognition of common values in the scientific endeavors of East and West, a recognition which has at times been easier in the physical than in the behavioral and medical sciences, but is needed in every respect. And since it is the rapid development of physics that has made us so dangerous to one another, is it not fitting that we should get together over the great problem of detecting what makes us so frail and to join hands in the healing of the sick?

xiv

Hans-Lukas Teuber Cambridge, Massachusetts June, 1965

Preface

Higher Cortical Functions in Man marks an important accomplishment. Luria has, with one well-aimed stroke, managed to bring clinical neuropsychology back into the mainstream of scientific endeavor, while at the same time guarding the spirit and substance of the Soviet experience in this area of science. The volume is a documentary of bedside observation and experiment in the tradition of von Monakov and Goldstein-but the observations and the experiments are made in the image of Sechenov, Vigotsky, and Pavlov instead of Kiilpe, Brentano, and Wertheim. The reflex is regnant-but not the reflex arc. The volume is replete with evidence that reflex organization invariably involves a comparison between current input and residues of experience. Reflex organization is everywhere conceived and shown to be a two-way street whose traffic pattern is built of feedback between the central nervous system and peripheral sensory and motor structures. These are indeed current views; yet, as portrayed by Luria, they fall into place as naturally as if neurologists and psychologists had been groping in their various ways toward just this resolution of their dilemmas.

Higher Cortical Functions in Man is notable for another reason. These are the years when reticular systems, hypothalamic mechanisms, and other "diffuse," "facilitatory," and "inhibitory" processes are of central concern. Here, on the other hand, is a strong and sophisticated statement that does not flinch at complexities. This strength of statement is derived not from preconceived prejudice but flows from observation and experiment. Differences between neural systems and subsystems and their hierarchical relationships are spelled out. The hierarchical principle is then applied to unravelling disturbances of cognitive processes. But perhaps the most important achievement concerns the communicative behavior which ceases when the cortical mantle is destroyed: Here Luria applies the fruits of recent linguistic research to the problem of centrally-produced speech disorders.

In each chapter the historical context in which Luria's own and other current investigations are rooted is clearly spelled out for the reader; should,

xv

PREFACE

perchance, prejudice inadvertently be perpetrated it is openly declared for all to see. We are indeed fortunate to have available in English such a readable translation of an important contribution to neuropsychological knowledge by one of the outstanding Soviet scientists of our time.

xvi

Karl H. Pribram Stanford University May, 1965

Foreword

The purpose of this book is to analyze the disturbances of higher mental functions caused by local lesions of the brain.

The term "higher cortical functions" is a generally accepted one in the neurological literature, and it is used both in the title and in the text of this book. This has been done deliberately, although it is obvious that the higher mental processes are functions of the brain as a whole and that the activity of the cerebral cortex can be examined only in conjunction with that of nervous structures at lower levels.

Although the generalizations in this book are based on observations made during the past 25 years, and although an attempt has been made to correlate our findings with those presented in the literature, it cannot be said that this survey of the subject is exhaustive. An evaluation of the progress made in this area of study shows only too clearly that we are still only in the infant stages of the investigation of this complex field.

In describing disturbances of the higher cortical processes in their most general fonn, the author has drawn from the wide range of clinical phenomena encountered in neurology and neurosurgery and has disregarded findings pertaining to the pathogenesis, development, and clinical manifestations of the disturbances occurring with different types of brain lesions. This book is documented with very few actual case reports; a special book would be required to deal adequately with this additional material.

Another feature of this book has largely been determined by the present state of research into disturbances of the higher cortical functions in man in the presence of local brain lesions. A wealth of clinical material is avail­able as a source of descriptions of such disturbances. After a careful clinicopsychological study of these disturbances, it is often possible to identify the underlying factors and to study important aspects of the cerebral organization of complex fonns of mental activity. For this reason, the psychological study of the cortical functions has become an indispensable part of the clinical investigation directed at diagnostic localization of a lesion and restoration of the disturbed brain functions, and this aspect of the subject receives due attention herein.

xvii

Foreword

In contradistinction to the abundance of clinical data, accurate physi­logical investigation of the abnonnal dynamics of the nervous processes accompanying local brain lesions is only in its infancy. Although extensive material is presently available on the pathophysiology of higher nervous activity in the presence of generalized organic brain lesions and psycho­neuroses, it is only recently that careful physiological investigations have begun to be made in patients with local brain lesions. That is why the results of neurodynamic investigations of cases of circumscribed brain lesions could not be presented as fully as would have been liked, and to remedy this deficiency is an important task for the future.

The author has been greatly helped by many colleagues and associates in the writing of this book. He is particularly indebted to A. N. Leont'ev, F. V. Bassin, G. I. Polyakov, S. M. Blinkov, M. B. Eidinova, B. V. Zeigarnik, Y. V. Konovalov, and T. O. Faller and his collaborators N. A. Filippycheva, E. N. Pravdina-Vinarskaya, and E. P. Kok.

The author is grateful to G. I. Polyakov for accepting the task of writing the chapter dealing with modern views on the structural organization of the brain, in which he incorporated the results of his many years of experience (Part I, Section 2).

The assistance given to the author in the preparation of this book by his close collaborator E. D. Khomskaya has been especially valuable. The principal propositions in this book were fonnulated jointly with her, and it can rightly be said that this book is largely the result of our combined activity.

The author wishes to express his gratitude to the staff of the N. N.

Burdenko Institute of Neurosurgery of the USSR Academy of Medical Sciences, Moscow, with whom he has been actively associated for nearly a quarter of a century, and to its Director, B. G. Egorov, who has done so much to facilitate our investigations of patients with local brain lesions.

The author is greatly indebted to Dr. Basil Haigh for the translation of the book, and especially to Professor Joseph Wortis for his invaluable help in editing the English text of the volume.

The author first began his clinicopsychological investigations of cases of local brain lesions more than 30 years ago under the guidance of his friend and teacher L. S. Vygotskii. Much of what is written in the following pages may therefore be looked upon as a continuation of Vygotskii's ideas, and this book is dedicated to his memory.

xviii

Foreword to the Second Edition

A second edition of Higher Cortical Functions in Man was called for soon after publication of the first edition. This is a measure of the current impor­tance of the matters discussed in it and the wide interest in the problem of higher cortical functions shown by psychologists, neurologists, and physio­logists; interest in this field has grown considerably as a result of progress in bionics and the theory of self-regulating systems, on which attention has recently become focused.

The discussion which the book has provoked in the press has not called any of its basic propositions into question, and the author does not consider that any substantial corrections are necessary. However, progress in the sci­ence of the brain and its neuronal organization in recent years has necessi­tated a number of additions, and these and others have been included by the author in the new edition.

Much has been written in recent years on the functions of the limbic sys­tems of the brain and disturbances of the emotions and memory that arise in lesions of those systems. A short section devoted to research in this field has accordingly been introduced into the book. The author realizes that this section cannot hope to cover completely all the evidence that has accumu­lated in recent years on this subject; however, the basic theme of the book, the study of higher cortical functions, can allow only the most cursory examination of the data relating to the functions of this region.

Investigations of the functions of the components of nerve tissue con­ducted at the single neuron level have of late made rapid development. These investigations, published in several different countries, have yielded new and invaluable material, and indeed it would seem that within the life­time of the present generation, the science of the functional organization of the cerebral cortex will undergo a radical change and assume a totally dif­ferent form.

Since this new field of research lies outside the author's field of com­petence, he is deeply grateful to O. S. Vinogradova for undertaking the task of describing, in a short section, the results of recent research at the

xix

Foreword to the Second Edition

neuronal level in laboratories in the West a~d in E. N. Sokolov's laboratory at Moscow University, where she has been directly involved in this activity.

The section on the functions of the frontal lobes has been rewritten, draw­ing heavily on data obtained by E. D. Khomskaya and her colleagues, who have contributed much valuable material to this problem in recent years. The book also includes material from the author's friends and colleagues that is published in the complete form in the book The Frontal Lobes and Regulation of Psychological Processes, edited by E. D. Khomskaya.

Neuropsychology, the basic facts of which are dealt with in this book, has developed in recent years into a widely branching field of research. The au­thor hopes that this second edition of his book will be useful to workers in this new branch of science.

xx

Preface to the Second American Edition A long time has elapsed since the publication of the first edition of this book, in which I attempted to lay the foundations of neuropsychology as a new branch of science. Indeed, it is already a fair time since the publication of the second Russian edition, which was prepared 10 years ago and published in 1969.

In the intervening decade some really important work has been done by the author and his group, and the same can be said for the whole wide field of neuropsychology. The old topics of neuropsychology, already studied in the past, have been probed to a much greater depth; new problems not hitherto investigated have appeared. The literature analyzing higher corti­cal functions in man from the standpoint of neuropsychology and its allied disciplines has grown enormously.

These developments have compelled the author to look carefully at the previous text of this book and, while retaining its basic features, to rewrite some sections and to add information on new problems not previously mentioned.

In the present edition, which differs substantially from the first Russian and first American editions of this book, and which is also substantially en­larged compared with the second Russian edition, the author has added new and very important data.

The section dealing with the psychophysiological mechanisms of activa­tion, which is particularly afflicted by lesions of the frontal lobes, has been fully revised. This section is written by one of the author's closest colleagues, E. D. Khomskaya, whose investigations have developed particularly actively in the last decade: the results have been summarized in her book The Brain and Activation, published (in Russian) in 1972, and in many papers with her colleagues.

A new chapter on disturbances of higher cortical functions in deep brain lesions has been added.

Important additions reflecting the work of the author and his collabora­tors in the last decades have been made in the section on memory processes,

xxi

Preface to the Second American Edition

methods of their investigation, the forms of their disturbances, and the mechanisms lying at the basis of these disturbances.

A new section on interaction between the hemispheres, and the role which each plays in the course of complex types of psychological activity, has been introduced. This section was deliberately left out of earlier editions of the book, but recent investigations by the author's colleague E. G. Simer­nitskaya have taken the first steps toward the analysis of the internal mecha­nisms of this interaction. Consequently, despite the very -incomplete studies which have so far been made of this problem, the many articles which have been published demanded that a place be found for its discussion in this edition.

The author has deliberately decided to include only data obtained in the last 10 to 12 years in his laboratory and has not attempted to cover the vast literature on problems in neuropsychology containing the results of re­search in many different countries. These results have been published both in special monographs and in articles appearing in specialized journals such as Neuropsychologia, Cortex, and Brain and Language, not to mention many collections and periodicals devoted to advances in neurology and neurophysiology. The writer also decided with regret that he could not do justice to the work of his physiologist colleagues, who, during the last 10

to 15 years, have made tremendous advances and have opened up new and hitherto inaccessible ways of analyzing the intimate mechanisms of the working of the human brain.

To deal adequately with all these matters and to review in a succinct form the whole of the vast literature in this field would be far beyond the author's capacity. The author strives to maintain a modest outlook on his abilities and, more than anyone else, he is aware of the deficiencies of this book.

If, despite all that has been said, the decision is taken to publish the ex­tended edition of Higher Cortical Functions, its purpose is simply to reflect a stage in the development of neuropsychology in which the author has participated directly, and which, of course, will see considerable progress as a result of future research currently taking place in many different countries by a large army of workers.

When presenting this revised version of the book for publication the au­thor would lik~ to extend his thanks once again to the staff of the N. N. Burdenko Institute of Neurosurgery, Academy of Medical Sciences of the USSR, with whom he has been connected now for 40 years, and to the publishers Basic Books and Plenum, for deciding to publish the new edition.

xxii

A. R. Luria Moscow June, 1977