Hood, Bruce - Supersense

As I write these heady sentences, I pause and pick up my coffee mug. This simple act is one of nature’s miracles. First, who made that decision if not me? More disturbingly, how can my mental thought cause my physical hand to move? How does mind interact with body? These are some of the most profound issues that have preoccupied thinkers for millennia, but most of us never even bother to consider how amazing these questions are. This is because we do not see a problem at all. We treat the mind and the body as separate because that is what we experience. I am controlling my body, but I am more than just my body. We sense that we exist independently of our bodies.

For most of us, if feels as if we spend our mental life somewhere resident behind our eyes, inside our heads. If we want to see what is behind us, we steer the ship around in order to look. If we want the coffee, we engage the coffee acquisition mechanisms. We feel like pilots controlling a complicated meat machine. There is only one Numskull in control inside my head, and it is I. But how can a nonphysical me control the physical body? How can a ghost inside my head pull the levers?

The dualist philosopher René Descartes proposed that the mental world must control the physical one through the pineal gland deep in the middle of the brain, which he called the seat of the soul. 31Descartes’s solution represents dualism, which requires that there be a soul that is separate from the body and yet in control of the body. But substance dualism must be wrong. The mind is not separate from the body but rather a product of that three-pound lump of gray porridge in our heads. When you damage, remove, stimulate, probe, deactivate, drug, or simply bash the brain, the mind is altered accordingly. In the last century, the great Canadian brain surgeon Wilder Penfield pioneered operations on awake patients for the treatment of epilepsy, including his own sister. He would expose the surface of the brain and then stimulate the region he was about to operate on to make sure that he was avoiding motor areas that might leave the patient paralysed. When he stimulated the brain directly, the patients experienced movements, sensations, and vivid memories. They tasted tastes, smelled smells, and relived past experiences. Direct stimulation proved that mental life is a product of the physical brain.

Even if there were a seat of the soul that controls our body, how could we explain the relation between these two types of substance, the one immaterial and the other material? In other words, how could an immaterial substance act on a material one? It’s not clear how this could work. Descartes’s way of solving the mind–body problem, by suggesting a soul that controls the body through the pineal gland, crosses the boundaries between what we know about mental states (that they are immaterial) and what we know about physical states (that they are material). If something nonmaterial could act directly on something material, this would require a mechanism beyond our natural understanding. It would have to be supernatural.

And yet this is exactly what all of us experience on a daily basis. We don’t just believe that we are different from our bodies, but rather, as Bloom points out, that we occupy them, we possess them, we own them. Again, this is an illusion that the brain creates for us. For example, when you cut yourself, you feel the pain in your finger, but it is in fact in your brain. When you take a painkiller, it works by altering the chemistry of your brain, not your finger. And yet you feel pain in your finger. Patients unfortunate enough to lose a leg or an arm through amputation often experience their missing limb. 32Just like real limbs, these ‘phantom limbs’ get itchy and can be tickled, but they too are an illusion. They are a product of a brain that has failed to update the loss of a body part in its overall map. As if some controller Numskull is looking at the schematic for the factory floor and has not realized that one section has been closed down. The brain areas previously responsible for receiving signals from the missing limb continue to fire away as if the limb were still connected. These examples prove something very disturbing. The brain creates both the mind and the body we experience. A physical thing creates the mental world we inhabit.

This experience of mind is personal and unavoidable. The Harvard psychologist Dan Wegner thinks that the experience of conscious free will in our minds may work like Damasio’s emotional somatic marker. 33Remember how emotions help us in our decision-making by giving us a sense of certainty? Wegner thinks that the experience of conscious free will works in a similar way. My body may tell me that it wants a slurp of coffee, but I experience the decision as my desire to have a drink. This enables me to keep track of my decisions by enriching them with a feeling of control. This is why we have the experience of purposeful decision-making and conscious appraisal. We need to take note of events for future reference. But we would be wrong in assuming that our mental experience at the time is responsible for the decisions we make.

Is all human mental life like this? What about plans for the future, such as schemes for revenge, humanitarian goals, and the need to crack jokes or write popular science books? In what sense could a conscious automaton be responsible for the whole gamut of mental life and aspirations that seems aimed at a future that has not yet happened? The fact that human activities and mental experiences are complicated is not under question. But in the same way we look at complex structures or behaviours in the animal world, such as building a spiderweb or constructing a wasp nest, and wonder how things so complicated could have evolved in creatures to which we don’t attribute minds, then we must equally entertain the possibility that humans are just more sophisticated life forms – forms that are capable of making plans and anticipating outcomes. The factors that feed into these processes that lead to complex mental lives in humans are diverse and multifaceted. The mental experiences that accompany such processing are undeniable, but we don’t need to evoke a mind that exists independent of and separate from the physical brain to explain them.

Even as a scientist aware of the problem of substance dualism and why Descartes’s solution is necessarily wrong, I still cannot ignore the overwhelming sense of my own mind as separate from my body and in control of my body, but ultimately I know it is a product of my body. How do the two interact? That’s the mind–body problem. That’s what keeps me awake at night. If all my daily conscious experience of a ‘me’ residing in my head like a Numskull boss were actually true, then it would require a supernatural explanation to make sense of it. That’s because we have no natural explanation of how something that has no physical dimensions can produce changes in the physical world. This is why the mind–body problem is one of life’s great mysteries.

MIND MY BRAIN

The mind–body problem simply does not appear on most people’s radar. It is not a problem until someone points it out or you read books like this one. People have a vague notion that the mind and brain are somehow linked, but rarely do they stop to ponder how the two could actually talk to each other or how something nonphysical could interact with something physical. Most humans have experienced the consciousness of their own minds from an early age, even before they discovered they had a brain. Therefore, it’s not surprising that young children can tell you more about their mind than they can tell you about their brain. 34However, they rarely use the word ‘mind’, but rather use ‘me’, ‘my’, and ‘mine’. It’s a natural way to describe oneself. The brain, on the other hand, is something they have to learn about, and that comes with science education.