A.D. Craig - How Do You Feel?: An Interoceptive Moment with Your Neurobiological Self

HOW DO YOU FEEL?

HOW DO YOU FEEL?

An interoceptive moment with your neurobiological self

A. D. (Bud) Craig

PRINCETON UNIVERSITY PRESS

PRINCETON AND OXFORD

Copyright 2015 by Princeton University Press

Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540

In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TW

press.princeton.edu

All Rights Reserved

Library of Congress Cataloging-in-Publication Data

Craig, A. D.

How do you feel? : an interoceptive moment with your neurobiological self / A.D. (Bud) Craig.

pages cm

Summary: How Do You Feel? brings together startling evidence from neuroscience, psychology, and psychiatry to present revolutionary new insights into how our brains enable us to experience the range of sensations and mental states known as feelings. Drawing on his own cutting-edge research, neurobiologist Bud Craig has identified an area deep inside the mammalian brainthe insular cortexas the place where interoception, or the processing of bodily stimuli, generates feelings. He shows how this crucial pathway for interoceptive awareness gives rise in humans to the feeling of being alive, vivid perceptual feelings, and a subjective image of the sentient self across time. Craig explains how feelings represent activity patterns in our brains that signify emotions, intentions, and thoughts, and how integration of these patterns is driven by the unique energy needs of the hominid brain. He describes the essential role of feelings and the insular cortex in such diverse realms as music, fluid intelligence, and bivalent emotions, and relates these ideas to the philosophy of William James and even to feelings in dogs.How Do You Feel? is also a compelling insiders account of scientific discovery, one that takes readers behind the scenes as the astonishing answer to this neurological puzzle is pursued and pieced together from seemingly unrelated fields of scientific inquiry. This book will fundamentally alter the way that neuroscientists and psychologists categorize sensations and understand the origins and significance of human feelingsProvided by publisher.

Includes glossary.

Includes bibliographical references and index.

ISBN 9780-691156767 (hardback)ISBN 069115676-X (hardcover) 1. EmotionsPhysiological aspects. 2. Affective neuroscience. 3. Neurobiology. I. Title.

QP401.C7 2015

612.823342dc23

2014009903

British Library Cataloging-in-Publication Data is available

This book has been composed in Charis SIL

Printed on acid-free paper.

Printed in the United States of America

13579108642

Contents

List of Figures and Plates

List of Boxes

Preface

T his book presents a new perspective on the origin and significance of human feelings, that is, one based on recent neuroscientific evidence. It is not a book about connecting with your feelings or controlling your feelings, although the ideas described here could lead you to practical insights. In this book, I explain ideas about structures and connections in our brains that are associated with feelingsany and all feelings. Based on evidence acquired in my own laboratory and a wealth of converging evidence from others, I present a model that offers plausible neurobiological explanations for how feelings are generated in our brains, what feelings represent, and how we experience our feelings.

First, I will describe the characteristics of the neural basis for the affective feelings from our bodies, such as hot, cold, muscle ache, hunger, pricking pain, and so on; much of this evidence comes from results obtained in my own laboratory, and I explain how my colleagues and I obtained the evidence. I focus on the surprising findings, the anomalies that didnt quite fit, which finally made sense after I realized that the distinct feelings we have from our bodies are elements of a neural representation of the physiological condition of our bodies. Such sensory activity is needed first of all for homeostasis, the process that maintains the health of our bodiesand thus, it seemed most apt to use the term interoception for the sensory representation of the condition of the body, enlarging it to relate to all tissues of the body, instead of just the interior tissues, or viscera. I describe how a key imaging experiment that was intended to validate this conceptual shift in humans produced striking evidence that underlies the heart of this new perspective on feelings; the evidence demonstrated for the first time that subjective bodily feelings are based directly on interoceptive integration in insular cortex. The convergence of this evidence with findings by others in widely disparate fields of neuroscience, psychology, psychiatry, and clinical medicine suggested quite clearly that the neural substrates which substantialize bodily feelings also provide the basis for our subjective awareness of emotional and social feelings, like pleasure, anxiety, trust, and anger. Together these results provide a solid foundation for well-known ideas about the embodiment of emotional awarenessin particular, they support the JamesLange theory of emotion and its modern refinements, the somatic marker hypothesis and self-perception theory. They can explain how you feel.

As I present the evidence, I explain how the homeostatic principle of optimal energy utilization underlies the neural integration that produces interoceptive feelings, subjective awareness, and forebrain asymmetry of emotion. The evolutionary success of every living organism depends on efficient energy utilization, and the evolutionary pressure for interoceptive neural optimization was heightened by the increasing proportion of the bodys energy budget used by the hominid brain (approximately 25% in adult humans and 60% in infants); thus, the model is consistent with the social-brain hypothesis of evolutionary forebrain enlargement and with the anthropological recognition that energy utilization was a crucial arbiter of hominid brain evolution.