Basic Vision: An Introduction to Visual Perception

421 Pages·2012·18.6 MB·English

by  Robert Snowden

Basic Vision
An introduction to visual perception
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BASIC VISION
an introduction to visual perception

REVISED EDITION
Robert Snowden Peter Thompson Tom Troscianko
School of Psychology Department of Psychology School of Experimental Psychology
Cardiff University University of York University of Bristol
1
1
Great Clarendon Street, Oxford, OX2 6DP,
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© R. Snowden, P. Thompson, and T. Troscianko 2012
The moral rights of the authors have been asserted
First Edition copyright 2006
Revised Edition copyright 2012
Impression: 1
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British Library Cataloguing in Publication Data
Data available
Library of Congress Cataloguing in Publication Data
Library of Congress Control Number: 2011943527
ISBN 978–0–19–957202–1
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For Tom
30.01.53–16.11.11
Preface
This book had its beginnings rather a long time ago. Two of the authors were sitting
in a bar at Chicago airport on their return to the UK from a conference in Florida.
When they had finished bemoaning the miserable lot of a British academic, they
turned to another favourite topic of conversation: that there simply wasn’t a text-
book on visual perception that was quite right for the courses they taught. There
were books that were excellent but too difficult for most undergraduates, there were
books that were too boring and dull, and there were books that had some good bits
and some bad bits. So, they resolved, as you do after a few beers, to write their own.
Copious notes were scribbled on beer mats that day and, had either of the authors
thought to pick up the beer mats when their flight was called, this book might have
been published some years ago. A third author appeared later and volunteered to
cook food for all three for as long as it took to write the book, which did nothing to
encourage completion of the work.
The original edition of Basic Vision was published in 2006 and we have used it for
our own teaching courses ever since. We have been very pleased by the reaction of
students to it; astonishingly, they seem to have enjoyed the humour in the book and
they appreciated the level of explanation we aimed for. The only complaints we had
were that students who were not even taking the perception course were borrowing
copies of the book from the library to read just for fun! The success of the original
edition has meant that, despite our recalcitrant nature, the publishers were keen that
we update the book and release this revised edition.
In making the revision, we have had feedback from many colleagues who have sug-
gested various changes to the book. Some of these we have embraced but others of
these went against the ‘ethos’ of what we wanted to achieve—a ‘basic’ book on vision
that was fun to read. It also seemed to us that most of what we know about vision
had not changed dramatically in the last five years—many of the basic processes have
been known about for many years. So, this revised edition of the book represents
a little remoulding, quite a bit of polishing, and the inclusion of a little of the most
exciting recent developments in vision, rather than a dramatic rewrite of the book.
We have tried to remove the more crass errors (and we thank our clever students
and colleagues who identified more than 60 errors in the original edition!). We shall
blame the remaining mistakes on each other.
As hinted at above, this revised edition would not have occurred had it not been
for the bullying tactics of Oxford University Press. We thank everyone at OUP who
helped us with this version of the book, especially Holly Edmundson, without whose
Preface vii
constant nagging we would have never completed the task. We thank them all for
their persistence and patience in dealing with a, frankly, difficult set of authors.
The writing of a textbook takes an enormous amount of time. As in the original
edition, we would therefore like to thank our loved ones for allowing us the time to
complete this work.
Robert Snowden, Cardiff
Peter Thompson, York
Tom Troscianko, Bristol
September 2011
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Contents
Figure acknowledgements xiv
0 Introduction: a trailer to the book 1
An apology 2
The problem 2
Vision in action 6
Illusions 8
Damage to the system 12
The brain 13
The study of vision 17
1 The first steps in seeing 19
The eye 20
The photoreceptors 32
The retinal ganglion cells 35
Beyond the eye—the optic nerve 37
The lateral geniculate nucleus 38
2 Signalling changes 45
Introduction 46
A problem 47
Retinal ganglion cells and receptive fields 49
Receptive fields and image processing 51
Some effects of retinal processing 58
Conclusion 66
3 To the cortex 68
The primary visual cortex (aka V1, striate cortex, area 17) 69
Orientation selectivity 70
Organization of the primary visual cortex 75