Patricia Churchland:

"Touching a Nerve - The Self as Brain" (Norton, 2013)

(Copyright © 2015 Piero Scaruffi | Terms of use )
Patricia Churchland, who virtually invented a new field with her book Neurophilosophy (1986), collects a series of essays on different topics in this book whose overarching narrative is very materialistic: everything we are is due to the electrochemical activity of our brain ("me" is "it"). The first chapters on the soul and near-death experience are rather trivial.

Things get more interesting in the chapter about morality and altruism. She tracks down the origin of moral values to the bonding between mother and newborn in mammals. The mammalian brain (at least the female one) evolved to take care of helpless cubs. In particular, the mammalian brain evolved to feel pain when the baby feels pain. The mammalian brain is wired for care of others. That wiring happens in the hypothalamus, the same place responsible for hunger, thirst and lust. Two peptide hormones, oxytocin and vasopressin, predispose the human brain for socialization. For social animals isolation is a punishment, whereas other animals are perfectly happy to live alone: the difference attitude towards others lies in the way the brain works, and the working of the mammalian brain is conditioned by that original need, the need to care for helpless infants. One factor that dramatically altered the structure of the mammalian brain is the energy cost of being a warm-blooded animal (an animal whose activity that does not depend on sunlight to recharge). A more energy-efficient brain is a brain capable of learning. Hence the cortex, which appeared in mammals. Mammals are capable of learning and of problem-solving. Churchland puts all of these together and argues that moral behavior stems from the brainstem-limbic system and is shaped by reward-based learning and problem solving. These ideas was better articulated in her previous book "Braintrust - What Neuroscience Tells Us about Morality" (2011).

The chapter on aggressive behavior feels inconclusive. She starts out by saying that aggression is multidimensional (defending offspring, competing for females, etc). She explains how the male brain is formed in the mother's womb via the action of testosterone. During puberty hormones trigger the neural circuits that have been built during fetal development. An important part of this "male" circuit lies inside the hypothalamus, that controls male sexual behavior. In the female brain the hypothalamus is tightly connected with the amygdala, the organ that regulates fear. Hence the woman is less likely to be aggressive and more likely to be prudent.

The chapter on the self is another highlight. Patricia Churchland shows how confusing the topic is. Kant's definition of "free will", i.e. that nothing at all other than your will causes your actions, is untenable: countless circumstances affect your actions, and most of your actions are not even conscious. Whichever action we end up performing in a certain circumstance, it takes place because the brain ordered so. Nothing happens to the body without the brain being at least "informed" of it and in most cases "ordering" it. For every movement of your body there is a signal coming from or going to the brain. Nothing moves in the body without a signal traveling from or to the brain.

More humbly, the law deals with "intentional" and "voluntary" acts to determine your liability for the consequences of those acts; but even this is hardly satisfying. The law excuses someone who was not in control of himself, but it is not clear what that means. Who is the "someone" who is or is not in control? My brain is always in control of my body. In other words, who is the thing that "wills"? The brain is the organ that directs all my actions. If "i" am my brain, then i am always responsible for my actions. But my brain can object that it is simply a calculator: given the current brain state and some new input (external stimuli), the brain calculates a new state that results in some action. The brain is responsible for neither the external stimuli nor for the preexisting state (an evolution of the original genetically determined state after countless external stimuli).

The immediate cause of a new brain state (and therefore of a new action) is the external stimuli: are they the ones that "will" my behavior? If not, then is it the preexisting brain state, which, again, has been created by a long chain of reactions to stimuli all the way back to my gestation in my mother's womb when a random genetic event created my original brain? That original brain itself was an effect, not a cause. Everything that happened later to my infant brain was due to genetic programming and external stimuli. I did not "will" to have that original brain shaped in my mother's womb and i did not "will" to be bombarded by all those external stimuli. I have control over neither genes nor environment. It sounds unfair to hold me responsible for the actions caused by my current brain, shaped by events that were beyond my control. Neither my genes nor my neural connections were chosen by me; therefore i should never held responsible for what i do.

We often excuse people who "lost control" of themselves, but either we all have control of ourselves (everything we do is due to our brain). or we all have no control of ourselves (our brain was shaped by genes and environment). The word "control" must mean something else in order to make sense beyond the trivial sense of "my brain controls my body" or "the environment controls my brain". Nonetheless, we clearly understand the meaning of "self-control", and that makes a big difference on how we judge someone's actions. Churchland describes the case of a man who set fire to his barn and was initially deemed to be demented (and therefore excused), but later found to have set fire to the barn in order to collect insurance money (and therefore jailed). The action is the same, the consequence is the same, but in one case we assume that there was no "intent" whereas in the other we read an "intent". We excuse "insanity" based on rationality. If we "know" that an act will benefit us, then there is no way to tell the judge "i was not in control of myself". If we don't "know" that the act will benefit us, and in fact may turn out not to benefit us at all, then we are "not in control". The question then shifts to determining which part of the brain is the "knower" to be held responsible for the other parts of the brain that carried out the action. When that "knower" had nothing to do with the workings of the rest of my brain, the actions caused by my brain are excused by society.

We also excuse "insanity" based on something much harder to prove: the case in which someone "could not stop himself" from doing harm from someone else. This sounds odd, to say the least. Someone knows that he is doing something, and knows that it will harm someone else, but cannot stop from doing it. And, yet, you don't have to be insane in order to qualify for this type. Given strong enough a provocation, all of us react by doing something that "we cannot stop ourselves" from doing and that we may regret a few seconds later. This is the routine "loss of control" that is common throughout ages and genders. This "loss of control" is hard to distinguish from the one due to dementia or insanity. The "knower" in the brain is perfectly aware of what is going on but is incapable of stopping the rest of the brain from causing the action that the knower knows will be harmful.

We also excuse children. The law does not punish children the way it punishes teenagers and does not punish teenagers the way it punishes adults. The law indirectly recognizes that a part of the brain, the "knower" is not fully developed in children and teenagers in order to hold "them" accountable for their actions.

"Self-control" is valued not only by the law but also by ordinary folks. It is a virtue to be admired and imitated. Self-control is an exhibition of pristine "free will". In fact, that is precisely what parents teach children. In fact, that is precisely what society teaches criminals. In fact, that is precisely what mental institutions try to instill into the minds of the insane.

We also excuse people whose brain is affected by a disease. A tumor in your brain is considered an excuse for your behavior. However, the tumor is as much part of your brain as anything else in it. It was formed by processes inside your body. We consider that part of the brain as an invader, an offender, a hijacker, although it was created by my own brain. The excuse is that i didn't "know" that this tumor was growing inside my brain. I was "not in control" of this tumor. I did not "will" it, although it was created by my brain within my brain with no external intervention.

Sometimes we even excuse gullible people. Most gullible people are not locked into mental institutions. They live among their friends and are viewed as very nice (if sometimes funny) people precisely because they are gullible. One could argue, though, that gullible people have less of that "knower" in their brain. A criminal, who is thrown in jail for his actions, has, by definition, more of that "knower" in his brain, and that's why we throw him in jail (he was perfectly aware of his actions and of their harmful effects on others).

Back to Churchland's book, the next essay is about the subconscious. She resurrects the specter of Freud (which we hoped had been buried once and forever) but in a slightly different way. She first explains how we all tend to mimick each other, and how salespeople are in fact trained to mimick their customers in order to gain their trust. We unconsciously mimick the people we interact with. She then reminds us that we don't consciously pick the words we use. We decide what to say, but the way we say it, the specific arrangement of words that we use, is largely outside of our conscious control: words just come out of our mouth to express what we want to say. If writing, we have to keep rewriting the same sentence several times before we find the right wording. If speaking, we may add a lot of extra words simply because the words that first came out of our mouth were not the right ones. No matter how conscious we are of speaking, the speaking itself is unconscious.

Next she delves into the consciousness debate. Here the most interesting bit is about the US neurologist Nicholas Schiff, who has pinpointed the central thalamus as the region most responsible for conscious states ("Central Thalamic Contributions to Arousal. Regulation and Neurological Disorders of Consciousness", 2008). This region of the thalamus is directly connected to every part of the cortex; and viceversa: every part of the cortex is connected back to the central thalamus. When we are awake or dreaming, the neurons of the central thalamus fire at high frequencies (800-1000 Hz), eventually causing the overall 40 Hz wave that is associated with conscious states.

At the same time, the Dutch computational neuroscientist Martijn van den Heuvel and the German computational neuroscientist Olaf Sporns discovered that the brain contains a high-level network (or "rich club") of neurons, each representing a lower-level network that is specialized in a cognitive task ("Rich-Club Organization of the Human Connectome", 2011). The rich-club neurons are directly connected to each other. There are 12 main hubs of neurons in the brain, six per hemisphere.

Churchland marries these two findings with Bernard Baars' old intuition that the global conscious state must be created in a special workspace where all processing gets integrated, whereas unconscious states are due to neural processing that remains confined to some regions of the brain The three ideas together, in her opinion, constitute a major step forward to understanding where and how consciousness happens.

She closes the book with a reminder that the basic structures of consciousness are the same in the brains of other mammals. She doesn't think that human language is essential to consciousness,

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