Visual Pattern Analyzers (Oxford Psychology Series)

663 Pages·1989·35.04 MB·English

by  Norma Van Surdam Graham

Visual Pattern Analyzers
OXFORD PSYCHOLOGY SERIES
EDITORS
DONALD E. BROADBENT NICHOLAS J. MACKINTOSH
STEPHEN KOSSLYN ENDEL TULVING
JAMES L. MCGAUGH LAWRENCE WEISKRANTZ
1. The neuropsychology of anxiety: an enquiry into the functions
of the septo-hippocampal system
Jeffrey A. Gray
2. Elements of episodic memory
Endel Tulving
3. Conditioning and associative learning
N. 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
C.-J. Falmagne
7. Animal intelligence
Edited by L. 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
L. Weiskrantz
13. Profile analysis: auditory intensity discrimination
David M. Green
14. Spatial vision
R. L. DeValois and K. K. DeValois
15. The neural and behavioral organizations of goal-directed movements
Marc Jeannerod
16. Visual pattern analyzers
Norma Graham
OXFORD PSYCHOLOGY SERIES NO. 16
Visual Pattern
Analyzers
NORMA VAN SURDAM GRAHAM
Department of Psychology
Columbia University
OXFORD UNIVERSITY PRESS • New York
CLARENDON PRESS • Oxford
1989
Oxford University Press
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Copyright © 1989 by Oxford University Press, Inc.
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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,
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Library of Congress Cataloging-in-Publication Data
Graham, Norma Van Surdam.
Visual pattern analyzers / Norma Van Surdam Graham.
p. cm. — (Oxford psychology series ; no. 16)
Bibliography: p.
Includes index.
ISBN 0-19-505154-8
1. Pattern perception. I. Title. II. Series.
QP491.G69 1989
152.1'423—del9 88-34883 CIP
987654321
Printed in the United States of America
on acid-free paper
In memory of
Norma Van Surdam Keesler
Clyde C. Keesler
who were partners in a
heavy-construction-equipment dealership
in Prospect Park, Pennsylvania
and
Helen Tredway Graham
Evarts Ambrose Graham
who were professors at the
Washington University School of Medicine
St. Louis, Missouri
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Preface
Visual perception can be described crudely as a two-part process: First, the
visual system breaks the information in the visual stimulus into parts, and then
second, the visual system puts the information back together again (not in its
original form, however). Why should there be this analysis followed by a syn-
thesis? The information in the visual stimulus as it impinges on the observer's
eye (the retinal image or "proximal stimulus") is just a collection of points of
light. The correspondences between the proximal stimulus and the important
aspects of the world that is being perceived (the "distal stimulus") are far from
straightforward, as the discussions of philosophers, visual scientists, and, more
recently, computer scientists emphasize (e.g., see Hochberg 1978 and Marr
1982). Presumably, once the information in the proximal stimulus is analyzed
into parts by the visual system's lower levels, it can be more easily reassembled
by the visual system's higher levels to tell us what is where in the environment!
This book deals with many of the parts into which visual information is ini-
tially analyzed. Presumably, these are the parts that make economic and feasible
the subsequent computation of "what is where." But just as with all the kings'
men and Humpty Dumpty, current visual science knows much more about the
parts than about the subsequent computations that put them back together
again.
The parts that are the topic of this book are those relevant for patterns in space
and time; that is, for discussions of shape and motion. Color and three-dimen-
sionality are not discussed.
Our knowledge of these parts has come both from psychophysics and neuro-
physiology. This book's major topic is the psychophysical evidence—particu-
larly that from experiments measuring human observers' ability to detect and
identify near-threshold spatiotemporal patterns. Physiological "asides" are fre-
quent in the book, however (see sections 1.4, 1.5, 1.6, 1.7, 3.6.1, 3.6.2, 3.7.8,
5.4.4, 8.7, 12.7, and 13.13), as the psychophysics and physiology have gone
hand-in-hand.
Over the last quarter-century or so of such research an enormous amount has
been learned. That information has been scattered over the pages of many dif-
ferent journals with many of the researchers themselves having little idea of how
coherent the whole story has become. In fact, in the course of the eight years I
spent writing this book, my original suspicions of chaos were replaced by a sur-
prised sense of convergence and definitive conclusions. If one considers only
near-threshold patterns, the results from different investigators using different
methods turn out to agree remarkably well and add up to a consistent story of
the low-level analyzers that exist in the human visual system. Organizing this
viii Preface
material within a framework and making it part of a coherent story is the major
aim of this book.
This book is primarily for readers with a very serious interest in visual per-
ception or closely related fields. The prototypical reader might be a graduate
student in vision or perception or an established researcher in another area of
vision or perception. Much of the book (parts II through V on models of four
kinds of psychophysical experiments) is just as applicable to people working in
the psychophysics of audition, taste, or smell as it is to people working in vision.
On the other hand, the book does include a good deal of background material
since people entering the field of pattern vision can come from medicine (oph-
thalmology), from biology (neurosciences, physiology), from engineering and
physics (especially electrical and optical), from computer science, from experi-
mental psychology, or from the arts (fine arts, film).
ORGANIZATION OF THE BOOK
As shown in the figure, the first part of the book provides background material
about physiology and psychophysics (Chapter 1) and mathematics (Chapter 2).
(Chapter 2 is more important for understanding Chapters 4, 5, 6, 12, and 13 than
for the other chapters. Readers able to tolerate ambiguity could skim or omit
Chapter 2.)
The next four parts discuss four kinds of psychophysical experiments that pro-
vide information about the parts into which the visual stimulus is analyzed:
adaptation experiments (Chapter 3), summation experiments (Chapters 4, 5,
and 6), uncertainty experiments (Chapters 7 and 8), and identification experi-
ments (Chapters 9 and 10). For each kind of experiment, current explanations
(more formally, models) of these experimental results are discussed at length.
These models are illustrated using experimental results on the spatial-frequency
dimension, but the general logic applies to experiments on other dimensions in
pattern vision and in perception more generally. It is possible to read only the
first chapter of each of these four parts (Chapters 3, 4, 7, and 9) with little loss
of continuity.
The first chapter in the summation part (Chapter 4) along with the uncertainty
and identification parts (Chapters 7 through 10) cover what is sometimes called
multidimensional signal-detection theory. They could be read independently of
the rest of the book quite easily.
The sixth part of the book summarizes results on all seventeen pattern-vision
dimensions: spatial frequency, orientation, spatial position (2 dimensions), spa-
tial extent (2 dimensions), spatial phase, temporal frequency (velocity), tem-
poral position, temporal extent, temporal phase, direction of motion, degree of
direction-selectivity, mean luminance, contrast, eye-of-origin, and degree of
binocularity. Some readers might skip or skim the middle sections of the book
Preface ix
going directly from the introductory material to Chapter 11 (which discusses
general issues of interpretation that arise when multiple dimensions are at issue)
or even to Chapters 12 and 13, which summarize conclusions about analyzers
on different pattern-vision dimensions (Chapter 12) and about parametric sen-
sitivity on different pattern-vision dimensions (Chapter 13). The conclusions in
Chapters 12 and 13, however, do depend on the theoretical framework outlined
in the middle parts of the book. The final sections of Chapters 12 and 13 are
lists of studies organized by both the primary and secondary dimensions stud-
ied. Only authors and dates are given in these lists, but the full references can
be found in the bibliography.
An appendix at the end of the book lists the assumptions used in the models
of Chapters 3 through 10 both in order of appearance and in groups according
to function. There is an index of assumptions appearing before the topic index.
A list of briefly defined symbols appears after the Table of Contents and the
symbols also appear in the topic index (with Greek letters alphabetized imme-
diately following their English equivalents).