Cover blurb

 

The Centered Mind is about the nature and causal determinants of both reflective thinking and, more generally, the stream of consciousness. It argues that conscious thought is always sensory based, relying on the resources of the working-memory system. This system has been much studied by cognitive scientists. It enables sensory images to be sustained and manipulated through attentional signals directed at midlevel sensory areas of the brain. When abstract conceptual representations are bound into these images, we consciously experience ourselves as making judgments or arriving at decisions. Thus one might hear oneself as judging, in inner speech, that it is time to go home, for example. However, our amodal (non-sensory) propositional attitudes are never actually among the contents of this stream of conscious reflection. Our beliefs, goals, and decisions are only ever active in the background of consciousness, working behind the scenes to select the sensory-based imagery that occurs in working memory. They are never themselves conscious.

 

Drawing on extensive knowledge of the scientific literature on working memory and related topics, Peter Carruthers builds an argument that challenges the central assumptions of many philosophers. In addition to arguing that non-sensory propositional attitudes are never conscious, he also shows that they are never under direct intentional control. Written with his usual clarity and directness, The Centered Mind will be essential reading for all philosophers and cognitive scientists interested in the nature of human thought processes.

 

Endorsements

 

“Although the stream of consciousness seems intimately familiar to us, its underlying nature has been an enduring philosophical and psychological mystery. Carruthers presents a clear and deeply radical solution to this mystery, drawing together a massive array of empirical research in support of an attractively simple sensory-based account of conscious thought. He takes bold positions on a wide range of related issues, including the line between mental activity and passivity, the relationship between working memory and reflective thought, and the gap between our intuitive impressions of our conscious states and the real contents of those states themselves. For those who are curious about these questions, The Centered Mind is a terrific and accessible guide; for those who are already specialists in conscious thought, this book sets the agenda of future research.”

-- Jennifer Nagel, University of Toronto

 

“Peter Carruthers has long been one of our foremost empirically informed philosophers of mind. In this book, he presents a persuasive account of the mechanisms underlying conscious thought and reasoning. Carruthers integrates a wealth of empirical work in the cognitive sciences to develop a novel conception of working memory as the heart of conscious thought and reasoning. Philosophically sophisticated and steeped in psychology and neuroscience, The Centered Mind is essential reading for philosophers and for cognitive scientists concerned with the nature of consciousness and the nature, powers and limits of conscious reasoning.”

-- Neil Levy, University of Oxford

 

Reviews

 

“Carruthers’ book … merit[s] careful study from anyone interested in reflection and the stream of consciousness. Carruthers writes clearly and engagingly. He treats his traditional targets with respect. He presents an impressive array of empirical research while both getting into the details and fitting them all into an intelligible order. His aim throughout is to help us better understand the things themselves -- reflection and the stream of consciousness -- not to grind some metaphilosophical axe. Although I am doubtful about Carruthers’ main theses, I found reading his book and engaging with his reasoning to be instructive and illuminating.”

-- Elijah Chudnoff, University of Miami, in Notre Dame Philosophical Reviews

 

“This impressive, if difficult, book of ‘theoretical psychology’ critically integrates results from across the cognitive sciences into a theory of ‘reflection’. … [Carruthers] systematizes and advances ‘global workspace’ theories in the most comprehensive philosophical study yet of the sciences of ‘working memory’ … Even readers who disagree with Carruthers’ central claims will enjoy his rich discussions along the way of attention, motor imagery, temporal discounting, mind-wandering and creativity, fluid intelligence, animal cognition, and extended minds.”

-- John Sutton, Macquarie University, in The Australasian Journal of Philosophy

 

“In the end, I would like to say that The Centered Mind is an excellent book and one of the best examples of efforts to explain the mind scientifically. The book is definitely not an introductory one, but I would recommend it to anyone who is interested in a scientific explanation of the stream of consciousness because Caruthers’s clear writing and thorough referencing makes the book accessible even to beginners.”

-- Mihovil Lukić, University of Zagreb, in Prolegomena

 

“[I] am especially impressed by the compelling evolutionary narrative and evidence Carruthers proffers in chapter eight to anchor this account (the work described on avian remembering and prospection … alone merits its own manuscript). I find it remarkable that this serious, and much needed, philosophical treatment of the dense and convoluted constructs of attention and working memory leads us to a similar, sensorily dependent, account of the mind as Aristotle holds in the De Anima … ‘the soul never thinks without an image’ (431a16). Scholars have attempted to diffuse the anti-propositional content of this claim for millennia; however, if Carruthers is right, they may not have to.”

-- Javier Gomez-Lavin, CUNY, in Philosophical Psychology

 

Contents

 

Preface

Figures

 

1.  Introduction

1. On reflection

2. The importance of the issues

3.  Working memory

4. The sensory-based account

5.  The road ahead

6. Conclusion

 

2.  Propositional Attitudes

1. Beliefs and desires

2. Goals, decisions, and intentions

3. Active versus passive: A problem

4. The case for amodal attitudes

5. The case for structured attitudes

6. Conclusion

 

3.  Perception, Attention, and Consciousness

1. Kinds of consciousness

2. Global broadcasting

3. Consciousness and attention

4. The nature of attention

5. Amodal content in perception

6. Conclusion

 

4.  The Nature of Working Memory

1. Working memory, imagery, and perception

2. Working memory and consciousness

3. Working memory and attention

4. Mental rehearsal

5. The sensory basis of working memory

6. Conclusion

 

5.  The Unity of Working Memory

1. An amodal workspace?

2. The problem of self-knowledge

3. The importance of working memory

4. The case of the missing variance

5. The default network

6. Conclusion

 

6.  Working Memory in Action

1. Unconscious goal pursuit

2. Attention as action

3. Mental rehearsal and mental manipulation

4. Generating inner speech

5. Creativity and mind wandering

6. Conclusion

 

7.  Reasoning, Working Memory, and Attitudes

1. Dual systems of reasoning

2. How System 2 reasoning works

3. System 2 reasoning in action

4. A second mind?

5. An extended mind?

6. Conclusion

 

8.  The Evolution of Reflection

1. The central puzzle

2. The age of attention

3. Episodic memory and prospection in birds

4. Working memory in mammals

5. Evolutionary developments across species?

6. Conclusion

 

9.  Conclusion: The Conscious Mind as Marionette

1. Against the intuitive view

2. The positive picture

3. Implications for philosophy and future questions

4. Conclusion

 

References

 

Index of names

Index of subjects

 

Preface

 

 

The project of this book developed out of an aspect of my last one. In The Opacity of Mind (Carruthers, 2011a), I defended the claim that our knowledge of our own thoughts (our beliefs, goals, decisions, and intentions) is always indirect and interpretive, no different in principle from our access to the thoughts of other people. In order to know our own minds, I argued, we have to turn our mindreading capacities on ourselves, drawing inferences from sensorily-accessible cues (including not only our own overt behavior and circumstances, but also such things as our own inner speech and visual imagery). I argued that this account is supported by a wide range of data from across cognitive science. But I also critiqued a number of competing theories proposed by philosophers. One account that I considered briefly is that we have a special-purpose working-memory system that enables our thoughts to be conscious and widely available to many different faculties of the mind. Since the latter include the mindreading system, we are thereby given direct access to the nature and occurrence of those thoughts—our judgments, goals, decisions, and the rest. It only occurred to me later that views similar to this one are quite widespread in philosophy (albeit using different terminology), as well as having considerable intuitive appeal. Moreover, what is really at stake in this aspect of the debate goes well beyond the topic of self-knowledge. Rather, it concerns the very nature of the cognitive architecture that underlies conscious thinking and reasoning, as well as our explanation of the so-called “stream of consciousness” more generally. In consequence, the topic is important enough to be worthy of a book in its own right.

 

I rely on an extensive scientific literature on working memory and surrounding issues to make my case.[1] Since working memory is the cognitive system that we employ when we engage in conscious forms of thinking and reasoning, and since (I shall argue) the contents of working memory are always sensory based (depending upon visual, auditory, and other forms of sensory imagery), it seems to follow that conscious thinking, too, is sensory based. In that case non-sensory (or “amodal”) thoughts (including goals, decisions, intentions, and many forms of judgment, I shall suggest) are incapable of being conscious. Rather, on the account that I provide, they “pull the strings” in the background, selecting, maintaining, and manipulating the sensory-based contents that do figure consciously in working memory. Somewhat surprisingly, then, it turns out that the conscious mind is much like a marionette that is controlled and made to dance by off-stage actors, who do their work unseen. But the main focus of this book is as much about developing a positive theory of reflection and the stream of consciousness as it is about overturning natural philosophical ideas about the nature of reflection. For while there is a wealth of work in cognitive science that bears on the topic, no one has, in my view, successfully woven it all together into a unified account. As a result, the book should be of broad interest to cognitive scientists as well as to philosophers.

 

The genre of this book is a kind of theoretical psychology, and I count myself (for present purposes, at least) as a theoretical psychologist. Consider an analogy with theoretical physics. Theoretical physicists generally do not conduct experiments. Rather, they take the data provided by experimental physicists and use those data to build general models and theories. The training for the two fields is different, and there is mostly no overlap between the two groups of scientists. In psychology, likewise, there is room for people who attempt to unify and explain the evidence collected by others. This is especially likely to be useful where the data in question cut across disciplinary boundaries (as they do here), or derive from traditions of inquiry whose participants rarely interact with one another. (In philosophy, too, some would say that there is room for people who pursue philosophical questions experimentally; hence the nascent field of experimental philosophy. This book is definitely not of that ilk.) Sometimes theoretical psychologists will also engage in experimental work. This would be true of Steven Pinker, for example. But sometimes they do not. Here Daniel Dennett provides an obvious instance. In this book (even more than in my previous one) I try to emulate the latter’s example (albeit without attempting to match his inimitable writing style, and without sharing many of his views).

 

The initial work for this book was supported by a Research and Scholarship Award from the University of Maryland Graduate School, for which I am grateful. In addition, I wish to thank the following friends, colleagues, and students for their comments on some or all of an earlier draft: Â Heather Adair, Felipe De Brigard, Mark Engelbert, Peter Godfrey-Smith, Andrew Knoll, Neil Levy, Ryan Ogilvie, Georges Rey, Lizzie Schechter, Julius Schoenherr, Chandra Sripada, Xuan Wang, Evan Westra, Wayne Wu, and two anonymous readers for Oxford University Press. I am grateful to Susan Levi for her help in producing Figures 1, 2, and 3; and to Mark Fox for permission to reproduce Figure 6.



[1] The contents of working memory are generally believed to be conscious, drawing from many different unconscious regions of the mind. Moreover, those contents are likewise made available to many different unconscious mental systems that consume and respond to them. So working memory is, as it were, the place where “everything comes together” in the mind. Hence my title, The Centered Mind.