Evan Thompson, Ph.D.

Evan Thompson Ph.D.

Waking, Dreaming, Being

Spring Forward or Fall Back?

Changing Times for Neuroscience

Posted May 13, 2015

Spring means new beginnings, so maybe that’s why neuroscientists in recent weeks have been stepping out of the lab to muse about the long-term prospects of their efforts to understand the brain. It started with Cal Tech neuroscientist, Ralph Adolphs, writing a short piece called “The Unsolved Problems of Neuroscience,” which appeared in the leading journal, Trends in Cognitive Sciences. The blogger, Neuroskeptic, at Discovery Magazine, after calling attention to Adolphs' paper, followed with a post of his own, asking, “Where Are the Big Ideas in Neuroscience?” Neuroscientist, Micah Allen, at his well known blog, “Neuroconscience,” wondered, “Are We Watching a Paradigm Shift?” and offered a list of “7 Hot Trends in Cognitive Neuroscience According to Me.” Adolphs summarized the overriding reason for his reflections when he concluded, “In a nutshell, then, the biggest unsolved problem is how the brain generates the mind, conceived of in a way that does not simultaneously require answering the problem of consciousness.”

But solving unsolved problems, to say nothing of coming up with big ideas or shifting paradigms, requires thinking not just about the answers we still don’t have, but also about the kinds of questions we’re prone to ask. Asking how the brain generates the mind may not be the right question. It can lead us into thinking about the mind-brain relation in unproductive ways, ones that hinder rather than help neuroscience. Instead, we should ask how the brain facilitates the mind. This one word may make all the difference.

Asking how the brain “generates” the mind suggests that the brain brings the mind into existence—that special electrochemical or computational processes inside the brain produce the mind. According to this perspective, what neuroscience needs to figure out is how this generation happens. Brain imaging tools, such as fMRI (functional magnetic resonance imaging) or EEG (electroencephalography), however, aren’t enough to figure this out, because they show us the metabolic or electrical shadows of cognition without revealing how it’s generated. Computational neuroscience, which uses artificial neural network tools along with neuroimaging ones and studies the information-processing properties of the brain, seems better suited to the task, but here we run into a problem with the concept of “information.”

In one sense of the term, “information” refers to a measurable quantity of physical systems. This kind of information belongs to the province of information theory, a branch of applied mathematics. In another sense of the term, “information” has to do with meaning and belongs to the field of semantics. These two senses of the word and corresponding fields of study are fundamentally different. For example, you can measure the quantity of information in a string of characters without knowing anything about what the string means. The meaning of the string is what you get when you interpret the information it contains in one way or another in some context. Of course, “interpret,” too, is a semantic concept, so the study of meaning is inseparable from the study of the rules and practices governing interpretation—a study that comprises logic, linguistics, psychology, and philosophy, as well as anthropology and literary theory. The study of meaning goes well beyond the purview of neuroscience.

Although computational neuroscience deals in information, it has no established theory or model of how meaning or semantic information is generated in the brain. It’s not just that there are rival theories; it’s that we don't understand how to explain meaning in purely neural or computational terms. More generally, we don’t understand how it’s possible for a physical system, such as the brain, to generate meaning. So we don’t have a definitive way of deciding between rival theories. Indeed, this problem is just the problem of how the brain generates the mind in another guise.

Moreover, if, as some theorists have argued, it’s not possible to account for meaning without accounting for consciousness, then the proposal to bracket the problem of consciousness while trying to figure out how the brain generates the mind will not work. In any case, the problem of meaning is arguably just as much of a “hard problem” as the “hard problem of consciousness” (the problem of how consciousness arises from physical processes). It may even be the “really hard problem.”

Part of the problem, however, comes from thinking of the mind or meaning as being generated in the head. That’s like thinking that flight is inside the wings of a bird. A bird needs wings to fly, but flight isn’t in the wings, and the wings don’t generate flight; they generate lift, which facilitates flight. Flying is an action of the whole animal in its environment. Analogously, you need a brain to think, but thinking isn’t in the brain, and the brain doesn’t generate it; it facilitates it. The brain generates many things—neurons and their synaptic connections, ongoing rhythmic activity patterns, the constant dynamic coordination of sensory and motor activity—but none of these should be identified with thinking, though all of them crucially facilitate it. Thinking is an action of the whole person in its environment.

The problem with saying “the brain generates the mind” is that it leads us into thinking that the mind is literally inside the brain. Of course, no neuroscientist would say that the mind is inside the brain in exactly the way that brain cells are; everyone agrees that the mind isn’t concrete in that way. Rather, the mind is supposed to be a kind of abstract, informational pattern. Nevertheless, it’s supposed to be inside the brain in the sense of being instantiated there. My point is that we need a wider view.

Science already provides a wider view in the form of “embodied” cognitive science. To say that cognition is embodied means that it directly depends on the whole body and not just the brain. To put it another way, bodily activity and not just brain activity is part of cognition.

Take perception. From the embodied cognitive science perspective, to perceive isn’t to be in a particular internal brain state; it’s to be in an interactive relationship with the world, one in which bodily movements and not just neuronal states are part of perception. For example, experiments have shown that, even when the visual stimulus is exactly the same, active observers and passive observers perceive depth and three-dimensional shape differently, because motor action changes the perception. Of course, motor action generally changes perception—for example, moving your eyes changes the visual stimulation you receive. But here the stimulus changes, whereas in the experiments just mentioned, the visual stimulus stays exactly the same but the perception differs according to whether your body actively moves in relation to it or is passively moved in relation to it. In the case of active self-movement, the motor signals and proprioceptive signals (about the body’s position in space) directly determine what you see. Thus, self-generated motor activity contributes to the content of your visual perception, making motor action a part of seeing, not a mere accompaniment to it.

The point of this example is to illustrate that seeing doesn’t happen inside the brain; that’s not where it’s generated. Seeing happens in the interactive relationship between the body and the world. The brain crucially facilitates this relationship but it doesn’t generate it.

Another example is gesture. Linguist David McNeil argues that gesture isn’t a mere accompaniment to speech and thought; it’s an integral component of them. Gesturing, in his view, is thought in action. If this view is right, then thinking—at least, one major kind of thinking—isn’t generated inside the brain; it’s generated in and through the body’s expressive movement, which the brain facilitates.

To say that cognition is embodied also means that it’s “embedded” in the environment. The brain, the rest of the body, and the environment form a system, in which cognitive behavior, such as visual recognition or gesture and speech, happens as a systemic process. In the words of cognitive scientist, Randall Beer: “Behavior is a property of the entire coupled brain-body-environment system and cannot in general be attributed to any one subsystem in isolation from the others.”

For human beings, the brain-body-environment system is the one of symbolic culture. Psychologist Merlin Donald argues that we’re able to think in the ways we do because over millennia we’ve constructed symbolic cultures in which we’re thoroughly embedded. Technological devices, such as writing and computers, provide a new kind of “external memory.” How much mathematical thinking could you accomplish without this kind of memory? Biological memory and external memory together make up a hybrid cognitive system. Much of what we think and do would be impossible without this kind of system. Take navigating a large ship. As cognitive anthropologist Edwin Hutchins showed, this requires a distributed comptuational system made up of symbolic technologies put to use by many crew members. Navigation is a property of this entire system; it doesn’t happen in the head.

Donald calls the close association of biological nature and symbolic culture “brain-culture symbiosis.” The human brain is adapted to the environment of symbolic culture and can’t function properly unless it’s embedded in that environment; at the same time, that environment is a creation of the cognitive capacities that the human brain makes possible.

In sum, the brain, the rest of the body, and the environment, especially culture, generate the mind. The brain crucially facilitates the process, because without the brain, the body and the environment wouldn’t be related to each other in the right way so as to bring about the mind. But the brain doesn’t generate the mind; it facilitates it.

The moral of this story is that the biggest unsolved problem of neuroscience can’t be solved by neuroscience alone. Neuroscience needs embodied cognitive science. Mind doesn’t come from just what’s inside the brain but also from what the brain’s inside of.

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