Mental illness is different from physical illness.

Post 311 Oct 13 JDN 2458770

There’s something I have heard a lot of people say about mental illness that is obviously well-intentioned, but ultimately misguided: “Mental illness is just like physical illness.”

Sometimes they say it explicitly in those terms. Other times they make analogies, like “If you wouldn’t shame someone with diabetes for using insulin, why shame someone with depression for using SSRIs?”

Yet I don’t think this line of argument will ever meaningfully reduce the stigma surrounding mental illness, because, well, it’s obviously not true.

There are some characteristics of mental illness that are analogous to physical illness—but there are some that really are quite different. And these are not just superficial differences, the way that pancreatic disease is different from liver disease. No one would say that liver cancer is exactly the same as pancreatic cancer; but they’re both obviously of the same basic category. There are differences between physical and mental illness which are both obvious, and fundamental.

Here’s the biggest one: Talk therapy works on mental illness.

You can’t talk yourself out of diabetes. You can’t talk yourself out of myocardial infarct. You can’t even talk yourself out of migraine (though I’ll get back to that one in a little bit). But you can, in a very important sense, talk yourself out of depression.

In fact, talk therapy is one of the most effective treatments for most mental disorders. Cognitive behavioral therapy for depression is on its own as effective as most antidepressants (with far fewer harmful side effects), and the two combined are clearly more effective than either alone. Talk therapy is as effective as medication on bipolar disorder, and considerably better on social anxiety disorder.

To be clear: Talk therapy is not just people telling you to cheer up, or saying it’s “all in your head”, or suggesting that you get more exercise or eat some chocolate. Nor does it consist of you ruminating by yourself and trying to talk yourself out of your disorder. Cognitive behavioral therapy is a very complex, sophisticated series of techniques that require years of expert training to master. Yet, at its core, cognitive therapy really is just a very sophisticated form of talking.

The fact that mental disorders can be so strongly affected by talk therapy shows that there really is an important sense in which mental disorders are “all in your head”, and not just the trivial way that an axe wound or even a migraine is all in your head. It isn’t just the fact that it is physically located in your brain that makes a mental disorder different; it’s something deeper than that.

Here’s the best analogy I can come up with: Physical illness is hardware. Mental illness is software.

If a computer breaks after being dropped on the floor, that’s like an axe wound: An obvious, traumatic source of physical damage that is an unambiguous cause of the failure.

If a computer’s CPU starts overheating, that’s like a physical illness, like diabetes: There may be no particular traumatic cause, or even any clear cause at all, but there is obviously something physically wrong that needs physical intervention to correct.

But if a computer is suffering glitches and showing error messages when it tries to run particular programs, that is like mental illness: Something is wrong not on the low-level hardware, but on the high-level software.

These different types of problem require different types of solutions. If your CPU is overheating, you might want to see about replacing your cooling fan or your heat sink. But if your software is glitching while your CPU is otherwise running fine, there’s no point in replacing your fan or heat sink. You need to get a programmer in there to look at the code and find out where it’s going wrong. A talk therapist is like a programmer: The words they say to you are like code scripts they’re trying to get your processor to run correctly.

Of course, our understanding of computers is vastly better than our understanding of human brains, and as a result, programmers tend to get a lot better results than psychotherapists. (Interestingly they do actually get paid about the same, though! Programmers make about 10% more on average than psychotherapists, and both are solidly within the realm of average upper-middle-class service jobs.) But the basic process is the same: Using your expert knowledge of the system, find the right set of inputs that will fix the underlying code and solve the problem. At no point do you physically intervene on the system; you could do it remotely without ever touching it—and indeed, remote talk therapy is a thing.

What about other neurological illnesses, like migraine or fibromyalgia? Well, I think these are somewhere in between. They’re definitely more physical in some sense than a mental disorder like depression. There isn’t any cognitive content to a migraine the way there is to a depressive episode. When I feel depressed or anxious, I feel depressed or anxious about something. But there’s nothing a migraine is about. To use the technical term in cognitive science, neurological disorders lack the intentionality that mental disorders generally have. “What are you depressed about?” is a question you usually can answer. “What are you migrained about?” generally isn’t.

But like mental disorders, neurological disorders are directly linked to the functioning of the brain, and often seem to operate at a higher level of functional abstraction. The brain doesn’t have pain receptors on itself the way most of your body does; getting a migraine behind your left eye doesn’t actually mean that that specific lobe of your brain is what’s malfunctioning. It’s more like a general alert your brain is sending out that something is wrong, somewhere. And fibromyalgia often feels like it’s taking place in your entire body at once. Moreover, most neurological disorders are strongly correlated with mental disorders—indeed, the comorbidity of depression with migraine and fibromyalgia in particular is extremely high.

Which disorder causes the other? That’s a surprisingly difficult question. Intuitively we might expect the “more physical” disorder to be the primary cause, but that’s not always clear. Successful treatment for depression often improves symptoms of migraine and fibromyalgia as well (though the converse is also true). They seem to be mutually reinforcing one another, and it’s not at all clear which came first. I suppose if I had to venture a guess, I’d say the pain disorders probably have causal precedence over the mood disorders, but I don’t actually know that for a fact.

To stretch my analogy a little, it may be like a software problem that ends up causing a hardware problem, or a hardware problem that ends up causing a software problem. There actually have been a few examples of this, like games with graphics so demanding that they caused GPUs to overheat.

The human brain is a lot more complicated than a computer, and the distinction between software and hardware is fuzzier; we don’t actually have “code” that runs on a “processor”. We have synapses that continually fire on and off and rewire each other. The closest thing we have to code that gets processed in sequence would be our genome, and that is several orders of magnitude less complex than the structure of our brains. Aside from simply physically copying the entire brain down to every synapse, it’s not clear that you could ever “download” a mind, science fiction notwithstanding.

Indeed, anything that changes your mind necessarily also changes your brain; the effects of talking are generally subtler than the effects of a drug (and certainly subtler than the effects of an axe wound!), but they are nevertheless real, physical changes. (This is why it is so idiotic whenever the popular science press comes out with: “New study finds that X actually changes your brain!” where X might be anything from drinking coffee to reading romance novels. Of course it does! If it has an effect on your mind, it did so by having an effect on your brain. That’s the Basic Fact of Cognitive Science.) This is not so different from computers, however: Any change in software is also a physical change, in the form of some sequence of electrical charges that were moved from one place to another. Actual physical electrons are a few microns away from where they otherwise would have been because of what was typed into that code.

Of course I want to reduce the stigma surrounding mental illness. (For both selfish and altruistic reasons, really.) But blatantly false assertions don’t seem terribly productive toward that goal. Mental illness is different from physical illness; we can’t treat it the same.

How personality makes cognitive science hard

August 13, JDN 2457614

Why is cognitive science so difficult? First of all, let’s acknowledge that it is difficult—that even those of us who understand it better than most are still quite baffled by it in quite fundamental ways. The Hard Problem still looms large over us all, and while I know that the Chinese Room Argument is wrong, I cannot precisely pin down why.

The recursive, reflexive character of cognitive science is part of the problem; can a thing understand itself without understanding understanding itself, understanding understanding understanding itself, and on in an infinite regress? But this recursiveness applies just as much to economics and sociology, and honestly to physics and biology as well. We are physical biological systems in an economic and social system, yet most people at least understand these sciences at the most basic level—which is simply not true of cognitive science.

One of the most basic facts of cognitive science (indeed I am fond of calling it The Basic Fact of Cognitive Science) is that we are our brains, that everything human consciousness does is done by and within the brain. Yet the majority of humans believe in souls (including the majority of Americans and even the majority of Brits), and just yesterday I saw a news anchor say “Based on a new study, that feeling may originate in your brain!” He seriously said “may”. “may”? Why, next you’ll tell me that when my arms lift things, maybe they do it with muscles! Other scientists are often annoyed by how many misconceptions the general public has about science, but this is roughly the equivalent of a news anchor saying, “Based on a new study, human bodies may be made of cells!” or “Based on a new study, diamonds may be made of carbon atoms!” The misunderstanding of many sciences is widespread, but the misunderstanding of cognitive science is fundamental.

So what makes cognitive science so much harder? I have come to realize that there is a deep feature of human personality that makes cognitive science inherently difficult in a way other sciences are not.

Decades of research have uncovered a number of consistent patterns in human personality, where people’s traits tend to lie along a continuum from one extreme to another, and usually cluster near either end. Most people are familiar with a few of these, such as introversion/extraversion and optimism/pessimism; but the one that turns out to be important here is empathizing/systematizing.

Empathizers view the world as composed of sentient beings, living agents with thoughts, feelings, and desires. They are good at understanding other people and providing social support. Poets are typically empathizers.

Systematizers view the world as composed of interacting parts, interlocking components that have complex inner workings which can be analyzed and understood. They are good at solving math problems and tinkering with machines. Engineers are typically systematizers.

Most people cluster near one end of the continuum or the other; they are either strong empathizers or strong systematizers. (If you’re curious, there’s an online test you can take to find out which you are.)

But a rare few of us, perhaps as little as 2% and no more than 10%, are both; we are empathizer-systematizers, strong on both traits (showing that it’s not really a continuum between two extremes after all, and only seemed to be because the two traits are negatively correlated). A comparable number are also low on both traits, which must quite frankly make the world a baffling place in general.

Empathizer-systematizers understand the world as it truly is: Composed of sentient beings that are made of interacting parts.

The very title of this blog shows I am among this group: “human” for the empathizer, “economics” for the systematizer!

We empathizer-systematizers can intuitively grasp that there is no contradiction in saying that a person is sad because he lost his job and he is sad because serotonin levels in his cingulate gyrus are low—because it was losing his job that triggered other thoughts and memories that lowered serotonin levels in his cingulate gyrus and thereby made him sad. No one fully understands the details of how low serotonin feels like sadness—hence, the Hard Problem—but most people can’t even seem to grasp the connection at all. How can something as complex and beautiful as a human mind be made of… sparking gelatin?

Well, what would you prefer it to be made of? Silicon chips? We’re working on that. Something else? Magical fairy dust, perhaps? Pray tell, what material could the human mind be constructed from that wouldn’t bother you on a deep level?

No, what really seems to bother people is the very idea that a human mind can be constructed from material, that thoughts and feelings can be divisible into their constituent parts.

This leads people to adopt one of two extreme positions on cognitive science, both of which are quite absurd—frankly I’m not sure they are even coherent.

Pure empathizers often become dualists, saying that the mind cannot be divisible, cannot be made of material, but must be… something else, somehow, outside the material universe—whatever that means.

Pure systematizers instead often become eliminativists, acknowledging the functioning of the brain and then declaring proudly that the mind does not exist—that consciousness, emotion, and experience are all simply illusions that advanced science will one day dispense with—again, whatever that means.

I can at least imagine what a universe would be like if eliminativism were true and there were no such thing as consciousness—just a vast expanse of stars and rocks and dust, lifeless and empty. Of course, I know that I’m not in such a universe, because I am experiencing consciousness right now, and the illusion of consciousness is… consciousness. (You are not experiencing what you are experiencing right now, I say!) But I can at least visualize what such a universe would be like, and indeed it probably was our universe (or at least our solar system) up until about a billion years ago when the first sentient animals began to evolve.

Dualists, on the other hand, are speaking words, structured into grammatical sentences, but I’m not even sure they are forming coherent assertions. Sure, you can sort of imagine our souls being floating wisps of light and energy (ala the “ascended beings”, my least-favorite part of the Stargate series, which I otherwise love), but ultimately those have to be made of something, because nothing can be both fundamental and complex. Moreover, the fact that they interact with ordinary matter strongly suggests that they are made of ordinary matter (and to be fair to Stargate, at one point in the series Rodney with his already-great intelligence vastly increased declares confidently that ascended beings are indeed nothing more than “protons and electrons, protons and electrons”). Even if they were made of some different kind of matter like dark matter, they would need to obey a common system of physical laws, and ultimately we would come to think of them as matter. Otherwise, how do the two interact? If we are made of soul-stuff which is fundamentally different from other stuff, then how do we even know that other stuff exists? If we are not our bodies, then how do we experience pain when they are damaged and control them with our volition? The most coherent theory of dualism is probably Malebranche’s, which is quite literally “God did it”. Epiphenomenalism, which says that thoughts are just sort of an extra thing that also happens but has no effect (an “epiphenomenon”) on the physical brain, is also quite popular for some reason. People don’t quite seem to understand that the Law of Conservation of Energy directly forbids an “epiphenomenon” in this sense, because anything that happens involves energy, and that energy (unlike, say, money) can’t be created out of nothing; it has to come from somewhere. Analogies are often used: The whistle of a train, the smoke of a flame. But the whistle of a train is a pressure wave that vibrates the train; the smoke from a flame is made of particulates that could be used to smother the flame. At best, there are some phenomena that don’t affect each other very much—but any causal interaction at all makes dualism break down.

How can highly intelligent, highly educated philosophers and scientists make such basic errors? I think it has to be personality. They have deep, built-in (quite likely genetic) intuitions about the structure of the universe, and they just can’t shake them.

And I confess, it’s very hard for me to figure out what to say in order to break those intuitions, because my deep intuitions are so different. Just as it seems obvious to them that the world cannot be this way, it seems obvious to me that it is. It’s a bit like living in a world where 45% of people can see red but not blue and insist the American Flag is red and white, another 45% of people can see blue but not red and insist the flag is blue and white, and I’m here in the 10% who can see all colors and I’m trying to explain that the flag is red, white, and blue.

The best I can come up with is to use analogies, and computers make for quite good analogies, not least because their functioning is modeled on our thinking.

Is this word processor program (LibreOffice Writer, as it turns out) really here, or is it merely an illusion? Clearly it’s really here, right? I’m using it. It’s doing things right now. Parts of it are sort of illusions—it looks like a blank page, but it’s actually an LCD screen lit up all the way; it looks like ink, but it’s actually where the LCD turns off. But there is clearly something here, an actual entity worth talking about which has properties that are usefully described without trying to reduce them to the constituent interactions of subatomic particles.

On the other hand, can it be reduced to the interactions of subatomic particles? Absolutely. A brief sketch is something like this: It’s a software program, running on an operating system, and these in turn are represented in the physical hardware as long binary sequences, stored by ever-so-slightly higher or lower voltages in particular hardware components, which in turn are due to electrons being moved from one valence to another. Those electrons move in precise accordance with the laws of quantum mechanics, I assure you; yet this in no way changes the fact that I’m typing a blog post on a word processor.

Indeed, it’s not even particularly useful to know that the electrons are obeying the laws of quantum mechanics, and quite literally no possible computer that could be constructed in our universe could ever be large enough to fully simulate all these quantum interactions within the amount of time since the dawn of the universe. If we are to understand it at all, it must be at a much higher level—and the “software program” level really seems to be the best one for most circumstances. The vast majority of problems I’m likely to encounter are either at the software level or the macro hardware level; it’s conceivable that a race condition could emerge in the processor cache or the voltage could suddenly spike or even that a cosmic ray could randomly ionize a single vital electron, but these scenarios are far less likely to affect my life than, say, I accidentally deleted the wrong file or the battery ran out of charge because I forgot to plug it in.

Likewise, when dealing with a relationship problem, or mediating a conflict between two friends, it’s rarely relevant that some particular neuron is firing in someone’s nucleus accumbens, or that one of my friends is very low on dopamine in his mesolimbic system today. It could be, particularly if some sort of mental or neurological illness in involved, but in most cases the real issues are better understood as higher level phenomena—people being angry, or tired, or sad. These emotions are ultimately constructed of axon potentials and neurotransmitters, but that doesn’t make them any less real, nor does it change the fact that it is at the emotional level that most human matters are best understood.

Perhaps part of the problem is that human emotions take on moral significance, which other higher-level entities generally do not? But they sort of do, really, in a more indirect way. It matters a great deal morally whether or not climate change is a real phenomenon caused by carbon emissions (it is). Ultimately this moral significance can be tied to human experiences, so everything rests upon human experiences being real; but they are real, in much the same way that rocks and trees and carbon emissions are real. No amount of neuroscience will ever change that, just as no amount of biological science would disprove the existence of trees.

Indeed, some of the world’s greatest moral problems could be better solved if people were better empathizer-systematizers, and thus more willing to do cost-benefit analysis.