A science of mind

We spend an enormous number of our waking hours thinking and talking about our thoughts, emotions, and experiences. For example, we wonder: Why did the waiter give me that unusual smile? Did my co-worker see me stealing those office supplies? How can I deflect my unwanted admirer's attention – or attract the attention of someone else? In trying to answer such questions, and in interpreting one another's behavior more generally, we make use of a vast body of lore about how people perceive, reason, desire, feel, and so on. So we say such things as: the waiter is smiling obsequiously because he hopes I will give him a larger tip; my co-worker does know, but he won't tell anyone, because he's afraid I’ll reveal his gambling problem; and so on. Formulating such explanations is part of what enables us to survive in a shared social environment.

This everyday understanding of our minds, and those of others, is referred to as “folk psychology.” The term is usually taken as picking out our ability to attribute psychological states and to use those attributions for a variety of practical ends, including prediction, explanation, manipulation, and deception. It encompasses our ability to verbally produce accounts couched in the everyday psychological vocabulary with which most of us are conversant: the language of beliefs, desires, intentions, fears, hopes, and so on. Such accounts are the stuff of which novels and gossip are made. Although our best evidence for what people think is often what they say, much of our capacity to read the thoughts of others may also be nonverbal, involving the ability to tell moods and intentions immediately by various bodily cues – an ability we may not be conscious that we have.

Our topic here is psychology, the self-styled science of the mind. Psychology's aim is to explain mental phenomena by describing the underlying processes, systems, and mechanisms that give rise to them. These hidden causal levers underlie all of our mental feats, including our richest conscious perceptions, our most subtle chains of reasoning, and our widest-ranging plans and actions. Although the phenomena of mind are intimately related to events occurring in the brain, these psychological explanations are, we will argue, distinct and autonomous relative to explanations in terms of neural processes and mechanisms. According to the view we present here, psychology and neuroscience are different enterprises. We certainly wouldn't claim that our ever-increasing understanding of how the brain works has nothing to say to psychology: on the contrary, they are complementary, because neuroscience can provide invaluable input to psychological theorizing (and vice versa, a point that we think is not stressed often enough). But our task will be to give a thorough account of the scope, methods, content, and prospects for a distinctive science of our mental lives.

This book is intended for students in philosophy, psychology, and the more cognitively oriented branches of neuroscience, as well as for readers who are merely curious about what these fields might have to contribute to our understanding of the mind. However, we hope that our professional colleagues will also find much to engage with here. So we’ve done our best to produce a book that holds interest on all levels – for undergraduates, graduates, and researchers alike. We have tried not to presuppose any significant background in any of the sciences that we discuss, and we hope that this book will serve as a useful companion for many of those pursuing the interdisciplinary study of cognition.

The slipperiness of experience

Consciousness and attention are two of the most vexing, hard-to-define aspects of mentality. No wonder, then, that even the most brilliant and articulate theorists, such as William James, are reduced to merely gesturing at them, or to seeming platitudes (“Every one knows what attention is”). Our everyday language for describing experience seems impoverished compared to the richness and dynamic pulse of the thing itself. Thoughts and intentions, daydreams and vivid bursts of emotion, coils and snippets of language, sights, aches, and the whole of the sensory world: these conscious experiences are always simply there, like a constant buzz. Take them away and, as Descartes astutely observed, it is hard to see what would be left of our minds as we know them.

Attention, by contrast, is not merely there, but also there for us. It can be commanded, albeit sometimes unwillingly. Notice the shape of someone's hand. Now, without shifting your gaze, notice its color and the texture of their skin. Notice the web of tiny lines, the fine hairs, any nicks or scars. Focus on just one of them. We have no trouble focusing our attention in these ways. In doing so, the character of our conscious experience shifts also. Of course, attention can also be dragged away against our will, by the intrusive ping of a text message or a nagging itch. When this happens, our train of conscious thought is disrupted and the source of our distraction takes center stage. Here we chronicle some contemporary ways of modeling attention and explore the possibility that these links between attention and consciousness are no coincidence but rather evidence for a deep theoretical connection between the two. In this way, perhaps two elusive mental phenomena can be grasped at once.

The minds of others

The term “folk psychology” was coined by philosophers to refer to the everyday capacities we have for predicting and explaining each other's behavior, as well as understanding each another as conscious, thinking, social beings. These capacities are also known as “commonsense psychology,” “mindreading,” or “everyday mentalizing.” The term “folk,” although it has a somewhat patronizing air, just refers to those of us who attempt to navigate the social world without appeal to the institutional apparatus of scientific psychology. At a minimum, folk psychology involves seeing others as having minds and attributing particular mental states and processes to them. Those that lack this capacity are said to be “mindblind”: they may interpret the world as containing animate, biological creatures, but they do not understand these creatures’ behaviors as actions driven by reasons, where reasons can include their perceptions, motives, and beliefs (Baron-Cohen, 1995). They may not even see the world as populated by persons who have inner lives of their own.

That we have such folk psychological skills from an early age is clear. However, folk psychology is not a transparent instrument. It cannot reliably be turned on itself to reveal its own inner workings. Although we often develop elaborate opinions about the operations of our own minds, they have at most prima facie standing as far as their accuracy is concerned. Our everyday perspective does not settle the question of how folk psychology itself operates: what sort of ability it is, what knowledge it draws on, and how it is situated vis-à-vis other cognitive systems. We turn now to some attempts to address these questions.

Explaining development

Minds, like living creatures, are born, grow, and change. Developmental psychology aims to describe these processes of change, and to characterize what the initial state of the mind is and how it gets from that initial state to its relatively stable and enduring mature form. The task for developmental psychology is to understand the factors that produce the normal initial state of the mind, and that take it from that initial state to its mature state, in much the way that developmental biology considers how new organisms are produced (e.g., as zygotes) and develop from embryos to reproductively mature adults.

In biology, early thinking about the origins of form involved preformationism, the doctrine that the form of a new organism somehow already existed, complete and entire, before its coming into material existence as an autonomous being. Where else could the form of a new, complete human being come from except from a tinier version of the same form, presumed to be curled up inside the parent cell, waiting until it could grow and be nourished in the womb? The theory, of course, only pushes the explanatory question back a step, since it fails as an ultimate explanation for the origins of biological form. This illustrates a common explanatory strategy: if there is no other plausible explanation for the existence of a certain form that appeals to known principles of assembly, then that form must not have been assembled at all. It must have already been present but hidden, just waiting for the right conditions to emerge.

The four E's

So far we have been looking at the mind from the perspective of traditional cognitive science. In this chapter we discuss a set of new and purportedly revolutionary approaches to cognition that have been gathering force in the past decade or so. These approaches go under the headings of Embedded, Embodied, Enactive, and Extended Cognition. These “four E's” propose a radical re-examination of how cognition should be modeled by the sciences, and they encourage a metaphysical shift in our view of what cognition itself is. These views raise a fundamental challenge concerning the very nature of how cognitive processes are distinguished from noncognitive ones. An upshot of these discussions will be to highlight the need for the cognitive sciences to settle a major foundational question, namely what makes something a cognitive system in the first place – that is, what the “mark of the cognitive” might be.

Very briefly, the four E's are as follows:

Mind–body relations

Psychology deals with mental phenomena, but these phenomena are intimately related to events in the body and brain. From the inside out, desires lead to plans, which result in intentions, which lead to actions. From the outside in, the environment impinges on us, producing perceptual episodes that lead us to update our beliefs and other models of what is going on in the world. All of these activities, from perception through belief updating, planning, and acting, involve continuous changes to underlying bodily and neural states. How should we understand the relation between these psychological and physical states? This is the mind–body problem as it has traditionally been understood by philosophers. It is the general metaphysical problem of explaining how psychological phenomena are related to physical, biological, and neurophysiological ones.

There are many possible philosophical stances on the mind–body relation, far too many for us to survey here. By far the greatest divide has historically been between dualists, who hold that the world contains two fundamentally distinct kinds of entities, the mental and the physical; and monists, who think that the world is fundamentally one type of thing through and through. Since at least the early twentieth century, dualism in most of its forms has been out of favor, paving the way for the rise of a thoroughgoing materialist or physicalist worldview. The demise of dualism has corresponded roughly with the increasing explanatory scope of the sciences. The more phenomena can be explained in physical and biological terms, the less need there is to posit special, nonphysical substances and properties. There gradually come to be fewer and fewer “gaps” in our understanding where dualistic explanations could carve out a distinctive role for themselves. But rejecting dualism only puts us on the side of some sort of monism. It does not tell us how we should understand the mind–body relation. For this, we need a positive theory.

The mind as a complex system

Brains and bodies are obvious examples of things – physical entities or objects. Like other paradigmatic physical objects, they have stable spatial boundaries and a host of other properties such as mass, density, and internal composition and organization. But are minds, or the ideas that fill them, also things? Are they object-like in these ways? Cartesian substance dualism, while it denied that the mind was something physical, nevertheless took it to be a kind of object or entity. Descartes argued further that the mind was not only a nonphysical object, but that it was also an indivisible object: it could not be decomposed into parts in any way whatsoever.

Ontologically, minds are systems, and some systems can also be object-like or entity-like. Atoms, solar systems, biological organisms, and hurricanes are all examples of entity-like systems. As systems they are decomposable into component parts and operations, but like many objects, they are also relatively persistent, coherent, and spatially circumscribed. Given the complex psychological and behavioral phenomena they give rise to, minds must be systems of extreme complexity. Like other complex systems, they have an internal design plan. For artificial computing devices, this plan corresponds to their circuit diagram – the description of their central processors (e.g., their instruction set), memory, system bus, various sub-controllers for storage, networking, audiovisual output, and so on. For biological organisms, this plan corresponds to their overall anatomical organization, their breakdown into organ systems (circulatory system, respiratory system, immune system), into individual organs and other active components (airway, lungs, diaphragm, etc.), and still further into specific types of specialized sub-organs, tissue and cell types, secretions and fluids, and so on.

Defining the senses

Psychologists have studied perception more deeply than any other of our cognitive capacities, and among the senses vision is by far the most closely scrutinized. Accordingly, although burgeoning philosophical attention has been paid in recent years to nociception (Aydede, 2006), audition (O’Callaghan, 2007), touch (Fulkerson, 2013), and olfaction (Batty, 2011), we mostly confine our attention here to vision. First, however, we address the more general question of how sensory systems are to be distinguished from the rest of cognition, as well as from each other.

The traditional division that posits five separate senses goes back to Aristotle, at least in recorded Western philosophical thought. Dividing the senses into touch, smell, taste, hearing, and sight makes sense on two intuitive grounds. First, these senses correspond to manifestly different sense organs. The eyes, ears, nose, tongue, and skin are relatively salient parts of the body, and their role in mediating different types of sensory interaction with the environment is pre-scientifically manifest. Second, these sensory divisions seem to be associated with distinct sensory phenomenology. To see something is a different kind of experience than to touch it or hear it. On the basis of anatomy and sensory experience, then, the Aristotelian divisions have some support.

On wordless minds

Which comes first, thought or language? Do thoughts about the world take shape and then become expressed in a language? Or does one acquire a language first, and only later, or simultaneously by virtue of the very tools of language, gain the ability to think about the world? Descartes notoriously took one of the hardest lines on this question. Speechless animals, he claimed, did not think at all. He may have even meant to imply by this that they lack experience of any kind. The ability to use language in a productive and creative way, for Descartes, was the only sure sign of mentality because it was a performance that could not be duplicated by a mere physical machine. Language is an infinite resource and one that is endlessly adaptable to new contexts. By contrast, the grunts of pigs and the cunning life-and-death dance of wolves hunting sheep are all purely material acts produced by mindless neural machinery.

To modern ears, this may sound peculiar. Language itself is an evolutionarily recent innovation, one that builds on a complex and extensive foundation of behavioral and cognitive processes. Once we adopt an evolutionary perspective, the phylogeny of cognition appears as a series of increasingly elaborate minds, and the Cartesian attempt to draw a bright line marking out the simultaneous emergence of thought and language seems fruitless (Dennett, 1997).