Visual Development

252 Pages·2013·7.827 MB·English

by  Nigel W. Daw

Nigel W. Daw
Visual
Development
Third Edition
Visual Development

Nigel W. Daw

V isual Development
Third Edition
Nigel W. Daw
Branford , CT , USA
ISBN 978-1-4614-9058-6 ISBN 978-1-4614-9059-3 (eBook)
DOI 10.1007/978-1-4614-9059-3
Springer New York Heidelberg Dordrecht London
Library of Congress Control Number: 2013949433
1st edition: © Plenum Press, New York 1995
2nd edition: © Springer Science + Business Media, Inc 2006
© Springer Science+Business Media New York 2014
This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or
part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of
illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way,
and transmission or information storage and retrieval, electronic adaptation, computer software,
or by similar or dissimilar methodology now known or hereafter developed. Exempted from this
legal reservation are brief excerpts in connection with reviews or scholarly analysis or material
supplied specifi cally for the purpose of being entered and executed on a computer system, for
exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is
permitted only under the provisions of the Copyright Law of the Publisher’s location, in its
current version, and permission for use must always be obtained from Springer. Permissions for
use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable
to prosecution under the respective Copyright Law.
The use of general descriptive names, registered names, trademarks, service marks, etc. in this
publication does not imply, even in the absence of a specifi c statement, that such names are
exempt from the relevant protective laws and regulations and therefore free for general use.
While the advice and information in this book are believed to be true and accurate at the date of
publication, neither the authors nor the editors nor the publisher can accept any legal responsibility
for any errors or omissions that may be made. The publisher makes no warranty, express or
implied, with respect to the material contained herein.
Printed on acid-free paper
Springer is part of Springer Science+Business Media (www.springer.com)
Pr eface
Research in the area of visual development has become a multidisciplinary
affair. Students who acquire an interest in the fi eld therefore need to under-
stand several different aspects of the subject. The development of acuity mea-
sured by psychophysicists is the concern of optometrists and ophthalmologists,
and depends on changes in the anatomy of the retina and the physiology of
cells in the visual pathway. Scientists working on the cellular, molecular, and
biochemical mechanisms lean on anatomical studies, physiology, and psy-
chophysics in designing and interpreting their experiments. Indeed, the labo-
ratories of the leading scientists working on the subject now all use a large
variety of techniques in their studies.
Because the study of visual development is pursued by workers in many
disciplines, from medicine to basic science, I have tried to write this book at
a level at which it can be understood by a variety of students: graduate stu-
dents in neurobiology and psychology, as well as optometry students and
ophthalmology residents. The text assumes some knowledge of basic terms
such as acuity, but a glossary is provided should the reader fi nd some words
that are unfamiliar. The emphasis is on facts and conclusions, rather than on
methods and procedures. Many details are left out.
However, I hope that the experts will also read the book. The subject has
become so wide-ranging that not many people have the time to read literature in
all aspects of it. The book is also intended for experts in one area to get a grasp of
the basics of the subject in other disciplines that are not their primary discipline.
To write a book covering such a wide variety of disciplines, I have had to
simplify. The book does not go into controversies in detail. Instead, it pro-
vides my summary of what seems to me to be the best evidence. Not every-
body will agree with my synthesis. Some experts will read it and be outraged
at some of my statements. However, my outrageous statements were intended
to be constructive: I hope that they will provoke thought and point the way to
more experiments that will carry the fi eld forward.
I am grateful to Colin Blakemore for inviting me to write this book. The
process has been an educational one for me, and led to a number of insights
which may have been apparent to others, but not to me. A number of friends
and colleagues have helped me in the preparation of the book. Grace Gray
in particular read the entire text twice, and improved it throughout. Robert
Hess went through the whole section on Visual Deprivation, and made
v
vi Preface
many valuable comments. John Lisman did the same for the section on
Mechanisms. Janette Atkinson, Marty Banks, Oliver Braddick, Jan Naegele,
Pasko Rakic, and Josh Wallman read individual chapters in their area of
expertise and made many corrections and improvements. Several of my col-
leagues in the Department of Ophthalmology—Ethan Cohen, Jonathan
Kirsch, Thomas Hughes, Colin Barnstable, Silvia Reid and Helen Flavin—
gave comments on various portions of the text, and Marc Weitzman read
two whole sections. I would like to thank them all. However, I did not adopt
all of their suggestions, and the errors and omissions are mine. I would also
like to thank Janet Hescock and Bob Brown for help in the preparation of
the text and fi gures, together with support from the Core Grant to Yale
University from the National Eye Institute.
Branford , CT , USA Nigel W. Daw
Preface to the Third Edition
It is almost 20 years since the fi rst edition of this book was written, and con-
siderable research has been done in that time. The development of vernier
acuity and contour discrimination have been more carefully defi ned. Genes
that play a role in myopia have been localized. New techniques using Gabor
patches in various confi gurations have enabled scientists to defi ne amblyopia
in more careful terms, particularly the concept of spatial uncertainty, and
whether it is due to undersampling or distorted sampling. Amblyopia was
never simply a matter of a defi cit in acuity, but it has taken careful experi-
ments to show exactly what it is beyond that.
Ten years ago, the molecules that govern the crossing of the optic nerve
fi bers in the chiasm, and which project to the contralateral side, and which to
the ipsilateral side were completely unknown. So were the molecules that
govern the topography of the projections within the visual system. Today, we
know some molecules involved in both these developmental events, as well as
some that mark the boundaries of the visual cortex.
The technique of optical imaging of the visual cortex has enabled scien-
tists to visualize the ocular dominance and orientation columns. Scientists
can now use this technique to study the development of these columns, and
the effect of various forms of visual deprivation on them, in a way that was
not possible with single unit recordings.
It has also become increasingly apparent that there are many critical peri-
ods in the development of the visual system. The critical period for the effect
of a particular form of visual deprivation in many cases lasts longer than the
period of development of the property affected, and the period during which
recovery can be obtained lasts longer still. Moreover, there are different criti-
cal periods for different properties. Properties handled at a higher level of the
system have a later critical period. In addition, the critical period can be
affected by the previous visual history of the animal, and by the technique
used to evaluate it. For all these reasons, the chapter on critical periods has
become much more involved.
Twenty years ago, quite a lot was known about mechanisms of long-term
potentiation and long-term depression, and not much about plasticity in the
visual cortex resulting from monocular deprivation. Today, a considerable
amount is known about mechanisms of ocular dominance plasticity, and what
is known about LTP and LTD does not add a great deal, so the chapter on the
latter has been eliminated.
vii
viii Preface to the Third Edition
The subject of the effect of out-of-focus images on the size of the eyeball has
also been a very active area of research. We still do not know how the signal
gets from the neural retina to the choroid and sclera, but there are a few mole-
cules known that increase in response to plus lenses and decrease in response to
minus lenses, or vice versa, that may be candidates for the signal.
Moreover, the best treatment for amblyopia has become much better
known, as therapists concentrate on properties other than acuity. Basic scien-
tists have quantifi ed the improvements that can be made by not patching the
amblyopic eye all of the time, and working with both eyes to improve binocu-
lar vision at the same time as the acuity in the amblyopic eye. Use of percep-
tual learning and video games has helped by increasing activity and attention
as the therapy is done. Many of the principles have been employed by pediat-
ric vision therapists for some time, but the publicity generated by “Stereo
Sue” and others has helped to broadcast them.
For all these reasons, it is high time that this book should be revised. The
aim of the book is the same as it was in the fi rst edition—to provide a short
summary of fi ndings in the fi eld that can be used by ophthalmology residents,
optometry students, graduate students in neurobiology and psychology,
senior undergraduates, and, since the fi eld is so diverse, for experts to read
chapters outside their area of expertise.
For this third edition, there is a Web site, w ww.visual-development.net ,
with links to various videos that illustrate points and procedures discussed in
the book. See also the list of useful videos after the table of contents.
I am most grateful to Paul Harris for reading the whole book and providing
a number of suggestions for clarifi cation, as well as for professional guidance
on the new chapter on “Treatment of Amblyopia.” I am also very grateful to
Terri Lewis, Len White, Mike Crair, Eileen Birch, Dennis Levi, Donald
Mitchell, John Lisman, Takao Hensch, and David Troilo, who provided com-
ments on individual chapters and hopefully caught most of my errors, but I am
sure that some remain. I also thank Simina Calin, my editor at Springer, for
all her help and guidance.
Contents
1 Introduction .................................................................................. 1
References ...................................................................................... 5
2 Functional Organization of the Visual System .......................... 7
General Anatomical Organization ................................................. 8
Function in the Retina .................................................................... 11
Function in the Lateral Geniculate Nucleus ................................... 14
Function in the Visual Cortex ........................................................ 16
The Columnar Organization of Cortex ...................................... 17
Parallel Processing Within the Visual System ............................... 19
Hierarchical Processing Within the Visual System ........................ 19
Higher Visual Areas ................................................................... 22
Summary ........................................................................................ 22
References ...................................................................................... 23
Part I Development of the Visual System
3 Development of Visual Capabilities ............................................ 27
Methods for Studying Infant Vision .............................................. 28
What Can Be Seen ......................................................................... 30
Faces .......................................................................................... 30
Biological Motion and Optic Flow ............................................ 30
Contour Integration, Illusory Contours,
and Continuity Behind Other Objects ........................................ 31
Depth Perception ........................................................................ 32
Fusion and Orthophoria ............................................................. 33
Color .......................................................................................... 34
Vision in the Periphery of the Visual Field ................................ 34
What Can Be Measured ................................................................. 35
Acuity ......................................................................................... 35
Contrast Sensitivity .................................................................... 36
Vernier Acuity ............................................................................ 39
Stereo ......................................................................................... 40
Prestereopsis and Poststereopsis ................................................ 42
The Prestereoptic and Poststereoptic Periods ............................ 43
Orientation, Direction, Movement ............................................. 43
Adaptation .................................................................................. 46
ix