Table Of ContentConsciousness
Consciousness
Confessions of a Romantic Reductionist
Christof Koch
The MIT Press
Cambridge, Massachusetts
London, England
© 2012 Massachusetts Institute of Technology
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Library of Congress Cataloging-in-Publication Data
Koch, Christof, 1956 –
Consciousness : confessions of a romantic reductionist / Christof Koch.
p. cm.
Includes bibliographical references (p. ) and index.
ISBN 978-0-262-01749-7 (hardcover : alk. paper)
1 . Consciousness. 2 . Mind and body. 3 . Free will and determinism. 4 . Life. I . Title.
B808.9.K63 2012
153 — dc23
2011040572
10 9 8 7 6 5 4 3 2 1
To Hannele
Contents
Preface ix
Acknowledgments xi
Chapter 1: In which I introduce the ancient mind– body problem, explain why
I am on a quest to use reason and empirical inquiry to solve it, acquaint you
with Francis Crick, explain how he relates to this quest, make a confession,
and end on a sad note 1
Chapter 2: In which I write about the wellsprings of my inner confl ict
between religion and reason, why I grew up wanting to be a scientist, why I
wear a lapel pin of Professor Calculus, and how I acquired a second mentor
late in life 11
Chapter 3: In which I explain why consciousness challenges the scientifi c
view of the world, how consciousness can be investigated empirically with
both feet fi rmly planted on the ground, why animals share consciousness
with humans, and why self-consciousness is not as important as many people
think it is 23
Chapter 4: In which you hear tales of scientist-magicians that make you look
but not see, how they track the footprints of consciousness by peering into
your skull, why you don’t see with your eyes, and why attention and
consciousness are not the same 41
Chapter 5: In which you learn from neurologists and neurosurgeons that
some neurons care a great deal about celebrities, that cutting the cerebral
cortex in two does not reduce consciousness by half, that color is leached
from the world by the loss of a small cortical region, and that the destruction
of a sugar cube – sized chunk of brain stem or thalamic tissue leaves you
undead 59
viii Contents
Chapter 6: In which I defend two propositions that my younger self found
nonsense — you are unaware of most of the things that go on in your head,
and zombie agents control much of your life, even though you confi dently
believe that you are in charge 75
Chapter 7: In which I throw caution to the wind, bring up free will, D er Ring
des Nibelungen, and what physics says about determinism, explain the
impoverished ability of your mind to choose, show that your will lags behind
your brain’s decision, and that freedom is just another word for feeling 91
Chapter 8: In which I argue that consciousness is a fundamental property of
complex things, rhapsodize about integrated information theory, how it
explains many puzzling facts about consciousness and provides a blueprint
for building sentient machines 113
Chapter 9: In which I outline an electromagnetic gadget to measure
consciousness, describe efforts to harness the power of genetic engineering
to track consciousness in mice, and fi nd myself building cortical
observatories 137
Chapter 10: In which I muse about fi nal matters considered off-limits to
polite scientifi c discourse: to wit, the relationship between science and
religion, the existence of God, whether this God can intervene in the
universe, the death of my mentor, and my recent tribulations 149
Notes 167
References 173
Index 179
Preface
What you ’ re holding in your hand is a slim exposition on the modern
science of consciousness. Within the space of a few hours, you can inform
yourself about where we natural scientists stand with respect to unravel-
ing one of the central questions of our existence — namely, how do subjec-
tive feelings, how does consciousness, enter into the world? “ Through
your head ” is the obvious answer. But that answer is not very helpful.
What is it about the brain inside your head that makes you conscious of
colors, of pain and pleasure, of the past and of the future, of yourself and
of others? And does any brain suffi ce? What about the brain of a coma-
tose patient, of a fetus, of a dog, a mouse, or a fl y? What about the
“ brains ” of computers? Can they ever be conscious? I ’ ll tackle these
questions and then some, including free will, a theory of consciousness,
and the b ê te noire of my research: the extent to which quantum mechan-
ics is relevant to understanding consciousness.
This book is not just about science, however. It is also a confession and
a memoir. I am not only a dispassionate physicist and biologist but also
a human being who enjoys but a few years to make sense of the riddle
of existence. I learned over the past years how powerfully my uncon-
scious inclinations, my beliefs, and my personal strengths and failings
have infl uenced my life and the pursuit of my life ’ s work. I experienced
what the novelist Haruki Murakami described in a striking interview:
“ We have rooms in ourselves. Most of them we have not visited yet.
Forgotten rooms. From time to time we can fi nd the passage. We fi nd
strange things . . . old phonographs, pictures, books . . . they belong to us,
but it is the fi rst time we have found them. ” You ’ ll learn about some of
these lost chambers as they become relevant to the quest I ’ m on — to
uncover the roots of consciousness.
Pasadena, California
May 2011
