Table Of ContentBlindsight : A Case Study and Implications Oxford
title:
Psychology Series ; No.12
author: Weiskrantz, Lawrence.
publisher: Oxford University Press
isbn10 | asin: 0198521928
print isbn13: 9780198521921
ebook isbn13: 9780585258096
language: English
subject Blind, Visual perception.
publication date: 1990
lcc: BF241
ddc: 152.14
subject: Blind, Visual perception.
Page i
Blindsight
A Case Study and Implications
Page ii
OXFORD PSYCHOLOGY SERIES
Editors
Nicholas J. Mackintosh Timothy Shallice
Daniel Schacter Anne Treisman Lawrence Weiskrantz
1. The neuropsychology of anxiety: an enquiry into the functions of septohippocampal
system Jeffrey A. Gray
2. Elements of episodic memory Endel Tulving
3. Conditioning and associative learning Nicholas J. Mackintosh
4. Visual masking: an integrative approach Bruno G. Breitmeyer
5. The musical mind: the cognitive psychology of music John Sloboda
6. Elements of psychophysical theory Jean-Claude Falmagne
7. Animal intelligence Edited by Lawrence Weiskrantz
8. Response times: their role in inferring elementary mental organization R. Duncan
Luce
9. Mental representations: a dual coding approach Allan Paivio
10. Memory, imprinting, and the brain Gabriel Horn
11. Working memory Alan Baddeley
12. Blindsight: a case study and implications Lawrence Weiskrantz
13. Profile analysis D. M. Green
14. Spatial vision R. L. DeValois and K. K. DeValois
15. The neural and behavioural organization of goal-directed movements Marc
Jeannerod
16. Visual pattern analysers Norma V. Graham
17. Cognitive foundations of musical pitch analysis C. L. Krumhansl
18. Perceptual and associative learning G. Hall
19. Implicit learning and tacit knowledge A. S. Reber
20. Neuromotor mechanisms in human communication D. Kimura
21. The frontal lobes and voluntary action R. E. Passingham
22. Classification and cognition W. Estes
23. Vowel perception and production B. D. Rosner and J. B. Pickering
24. Visual stress A. Wilkins
25. Electrophysiology of mind Edited by M. D. Rugg and M. G. H. Coles
26. Attention and memory: an integrated framework N. Cowan
27. The visual brain in action A. D. Milner and M. A. Goodale
28. Perceptual consequences of cochlear damage B. J. C. Moore
29. Binocular vision and stereopsis Ian P. Howard and Brian J. Rogers
30. The measurement of sensation Donald Laming
31. Conditioned taste aversion: memory of a special kind Jan Bures, Federico Bermüdez-
Rattoni, and Takashi Yamamoto
Page iii
Blindsight
A Case Study and Implications
L. Weiskrantz
University of Oxford
OXFORD PSYCHOLOGY SERIES NO. 12
CLARENDON PRESS OXFORD
Page iv
Oxford University Press, Great Clarendon Street, Oxford OX2 6DP
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Oxford is a trade mark of Oxford University Press
Published in the United States
by Oxford University Press Inc., New York
© L. Weiskrantz, 1986
First published 1986
First published in paperback 1990
New paperback edition published 1998
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, without the prior permission in
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This book is sold subject to the condition that it shall not, by way of trade or otherwise,
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A catalogue record for this book is available from the British Library
Library of Congress Cataloging in Publication Data
Weiskrantz, Lawrence.
Blindsight: a case study and implications.
(Oxford psychology series; no. 12)
Bibliography: p.
Includes indexes.
1. BlindnessCase studies. 2. Visual cortex
DiseasesCase studies 3. NeuropsychologyCase
studies I. Title II. Series.
RE725.W45 1986 617.7 86-12515
ISBN 0-19-852192-8 (Pbk)
Printed in Great Britain by J.W. Arrowsmith Ltd, Bristol
Page v
PREFACE
The case study that forms a large part of this monograph was prompted by the astute
observations of a clinical ophthalmic surgeon, Mr Michael Sanders, at the National
Hospital, Queen Square, London, who first noticed unexpected signs of residual capacity
within the 'blind' visual field of D.B., and reported his observations to Dr (now
Professor) Elizabeth Warrington, of the same hospital. She, in turn, drew my attention to
them, and together with Mr Sanders and Professor Marshall (in whose charge D.B. was a
patient at the hospital) we published our first investigations in 1974, soon after the
seminal report of Ernst Pöppel and his colleagues. Almost incidentally, we invented the
term 'blindsight'. The name caught on, and unwittingly became attached not only to
findings with D.B. but also, in other groups' studies, to a variety of aspects of residual
vision in 'blind' fields caused by cortical brain damage, especially when there is a
corresponding lack of awareness of the visual capacity by the patient. Perhaps the name
has also contributed to the ease of reference and debate by experimental psychologists,
neuroscientists, and philosophers of mind. Meanwhile, our research with D.B. continued
for several years but much of it has remained unpublished until now. The time seems
ripe, perhaps, to draw our corpus of findings together in one place, and to attempt to set
them and the issues that emerge from them in the perspective of neurological findings and
of other contemporary work.
Throughout the entire series of experimental studies reported here, spread over more than
ten years, Elizabeth Warrington was a constant research collaborator. She shared in
formulating the questions, designing the experiments, collecting every data point,
proposing and discussing hypotheses. I had hoped that she would be a co-author of the
whole, or failing that even a part, of this monograph, but she preferred the journal mode,
especially as the review and interpretation sections of this monograph continuously
expanded as they emanated from my word processor. I can only record my deepest
appreciation and my debt of gratitude to her.
The National Hospital also provided testing space and help of various kinds over several
years, for which I am very appreciative. The special and rare atmosphere at Queen Square
in fostering neurological research helped to make such a study feasible. I am also grateful
to technical staff in my own Department of Experimental Psychology at Oxford for much
help with the peculiar demands I frequently put them for apparatus and photographic
material, especially when we tested in Oxford. In particular, I thank Brian Baker, Roger
Barnes, Ray Bennett, and Jeremy Broad.
Page vi
I also acknowledge a special debt to the Medical Research Council, which supported my
clinical research as part of a larger programme grant to Professor Alan Cowey and me. By
very generously offering to take over my personal support completely from 1977 to 1979,
the Council enabled me to put aside the demands of University administration and to
devote myself fully to research. While it would have been an untold luxury to have had
longer, I am grateful that Oxford University allowed me to stand down from my other
duties during that period.
Oxford colleagues have provided much valuable discussion and criticism over several
years. Among these, Alan Cowey, whose own scientific contribution to related aspects of
this research will be evident to the reader, deserves special thanks. Parts of the material
reviewed here have been published elsewhere in journals, and acknowledgements will be
found in the text. I am very grateful to the Royal Society of London for making available
the portrait of Gordon Holmes, which originally appeared in Biographical Memoirs of
Fellows of the Royal Society, vol. 12 (1966).
Oxford University Press have been extraordinarily helpful and efficient at all stages of the
publishing process, and it is a pleasure to express my thanks to them. I am also grateful to
my wife for preparation of the indexes and help with the proofs.
Finally, of course, D.B. himself: a painstaking, forebearing, extremely cooperative and
astute participant, observer, and commentator over so many days and daysand still more
daysof testing, much of it no doubt very tedious to him. To him is owed an inestimable
debt.
L.W.
OXFORD
MARCH 1986
Page vii
INTRODUCTION TO THE NEW PAPERBACK EDITION OF
BLINDSIGHT
The original edition of Blindsight: A case study and implications, published in 1986, has
been out of print for some years, and I am very grateful for the invitation by Oxford
University Press to write a new Introduction for its reissue. The experimental findings
reported in the original work have not changed and so in that sense there would be no
point in a 'revised' edition. Of course, the review of the literature is a dozen years out of
date, but more recent reviews are available to which reference will be made in passing. I
am happy to keep alive a route to older papers. In this age of electronically fostered
breathlessness over the latest 'hot' findings, we are apt to forget that there were also
exciting and valuable papers with a vintage of more than ten years. Some of them have
become buried and forgotten in the contemporary avalanche but very much deserve to be
followed up experimentally and to be absorbed into contemporary debate and research
planning.
The 1986 book was principally a detailed account of experiments carried out by Elizabeth
Warrington and me over a ten year period on a single subject, D.B., who had a small
tumour surgically removed from his right visual cortex, causing a left hemifield visual
defect. The various experimental investigations were also accompanied by recorded
accounts of the verbal commentaries of his experienceor lack of itgenerated by the visual
stimuli used in the experiments. Some points of discussion in contemporary research,
both of empirical findings and of interpretation, continue to draw on comparisons with
the detailed evidence first reported on D.B., although this has now become difficult to
access directly. I also frequently cite evidence in Blindsight in a recent book,
Consciousness lost and found: A neuropsychological exploration (OUP, 1997). And so I
greatly welcome the reissue of the 1986 book as a research and reference source.
The 'D.B.' period ended with the publication of Blindsight, except for one further paper
(Weiskrantz 1987) that had been in the pipeline. Much of the subsequent research in the
field has been on a small number of intensively studied subjects, especially G.Y., who has
been investigated by several groups in ten or more centres in America and in Europe.
This field of research will probably continue to focus on deep studies of single subjects
for reasons that are discussed later. In passing, it is with sadness that one records the
tragic death in an accident late in 1996 of one of the principle investigators in this field,
Prof. Keith Ruddock of Imperial College, London, a gifted, sophisticated, and incredibly
painstaking scientist.
