Consciousness 8 — Neurophilosophy

As I make the transition in this series from philosophy to neuroscience, a natural step between these two disciplines (some might even call it an evolutionary step) would clearly be with the work of Patricia Churchland. She's a philosopher and neuroscientist who thinks that "philosophers are increasingly realizing that to understand the mind one must understand the brain."

I'll start with a few snippets from the podcast Nous, and its episode: Patricia Churchland on How We Evolved a Conscience. Churchland has a book out now called Conscience: The Origins of Moral Intuition, which I know is not the same thing as consciousness, but her discussion still has some relevant information for us.

• There were some philosophers who thought that if we went off and really studied the language of what we MEAN by the word consciousness, we’d be able to understand it. But other philosophers said, wait a minute, we might be mistaken about what we mean.
• Philosophy is a proto-science that must remain in touch with empirical discoveries. Science cannot tell us why something is right or wrong. However, science gives us all sorts of information that we take into account.
• Why did we become social? It started when we became warm blooded. Warm blooded creatures need about 10 times more nutrition though. One way to compensate for this requirement was for mammals to develop a new structure in the brain—a cortex—which allowed them to store a tremendous amount of information in the brain and to integrate it. The cortex relied on the subcortical parts of the brain for motivations, sleep/wake patterns, etc., but the cortex allowed for a kind of predictive prowess that had not been seen on the planet before.
• This all comes with a cost though. You can’t have memory unless you can build structure on the neuron. To tune the brain up to an environment requires that you are super immature when you are born. Snakes just are born and go off into the world. Mammals can’t. It was like evolution took a step backwards. This immaturity then led to the need for caregiving, which led to parents who care. Once caring for offspring turns on, family units, sociality, norms, and morality all take off.

That's a nice short, sharp, prod to get us philosophers studying the evolution of brains. A much more rigorous argument can be found in Churchland's essay "Neurophilosophy", which was a chapter in the fantastic edited collection How Biology Shapes Philosophy: New Foundations for Naturalism. Here are some useful points from that essay:

• The words “mind” and “brain” are distinct. Even so, that linguistic fact leaves it open whether mental processes are in fact processes of the physical brain. … [For physicalists] the important problem concerns how the brain learns and remembers, how the brain enables us to see and hear and think, and how it enables us to move our eyes, legs, and whole body. Their problem concerns the nature of the brain mechanisms that support mental phenomena. Interestingly, dualists also have a closely related set of problems: how does soul stuff work such that we learn and remember, see and hear and think, and so forth. Whereas in neuroscience, physicalists have a vibrant research program to address such questions, dualists have no comparable program. No one has the slightest idea how soul stuff does anything.
• Studies of a few patients who had suffered bilateral damage to the hippocampus showed them to be severely impaired in learning new things. … Memory losses associated with dementing diseases also linked memory with neural loss and further suggested the tight link between the mental and the neural. Important also are studies of attention using brain imaging along with single neuron physiology. These varied studies suggest that at least three anatomic networks, connected but somewhat independent of the other, are involved in different aspects of attention: alerting, orienting, and executive control.
• Developments in psychology, especially visual psychology, also implicated neural networks in mental functions, and this work tended to dovetail well with neuroscientific findings on the visual system. Explanations of color vision, for example, depended on the retina’s three cone types and on opponent processing by neurons in the cortical areas. … Visual hallucinations were known to be caused by physical substances such as LSD or ketamine, and consciousness could be obliterated by drugs such as ether, as well by other substances employed by anesthesiologists, such as propofol. No evidence linked these drugs to soul stuff.
• Short-term memory can be transiently blocked by a blow to the head or by a drug such as scopolamine; emotions and moods can be affected by Prozac and by alcohol; decision making can be affected by hunger, fear, sleeplessness, and cocaine; elevated levels of cortisol cause anxiety. Very specific changes in whole-brain activity corresponding to periods of sleep versus dreaming versus being awake have been documented, and explanations for the neuronal signature typifying these three states have made considerable progress. In aggregate, these findings weighed in favor of the physical brain, not of some spooky “soul stuff.”
• A methodological point may be pertinent in regard to the dualist’s argument: however large and systematic the mass of empirical evidence supporting the empirical hypothesis that consciousness is a brain function, it is always a logically consistent option to be stubborn and to insist otherwise, as do Chalmers and Nagel. Here is the way to think about this: identities—such as that temperature really is mean molecular kinetic energy, for example—are not directly observable. They are underwritten by inferences that best account for the mass of data and the appreciation that no explanatory competitor is as successful. One could, if determined, dig one’s heels in and say, “temperature is not mean molecular kinetic energy, but rather an occult phenomenon that merely runs parallel to KE.” It is a logically consistent position, even if it is not a reasonable position.
• With the benefit of contemporary physics, we can see that the causal interaction between nonphysical stuff such as a soul with physical stuff such as electrons would be an anomaly relative to the current and rather well-established laws of physics. More exactly, it would affect the law of conservation of energy. If brains can cause changes external to the physical domain, there should be an anomaly with respect to conservation of energy. No such anomaly has ever been seen or measured.

​Brief Comments
In previous posts, we saw how argument alone could make the case that thinking of consciousness as a non-material or panpsychic phenomenon is not helpful. Now, we see a glut of empirical evidence supporting the idea that consciousness is a physical phenomenon. Does that prove the case? Of course not. Knowledge is never proved in this way. Churchland's point, however, is exquisite, and right on the nose, that one can always dig their heels in about this and remain consistent, while also being unreasonable. This is something all philosophers should keep in mind.

What do you think? Any other important points jump out at you from these quotes? Let me know in the comments below.

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Previous Posts in This Series:
Consciousness 1 — Introduction to the Series
Consciousness 2 — The Illusory Self and a Fundamental Mystery
Consciousness 3 — The Hard Problem
Consciousness 4 — Panpsychist Problems With Consciousness
Consciousness 5 — Is It Just An Illusion?
Consciousness 6 — Introducing an Evolutionary Perspective
Consciousness 7 — More On Evolution