In a podcast released today, Robert J. Marks, director of the Walter Bradley Center, interviewed Dr. Andrew Knox, a pediatric neurologist at the University of Wisconsin School of Medicine and Public Health, about “How the Brain Breaks Down” ( #220, 5 January 2023).
The brain is a wonderful organ that has yet to be elucidated. Artificial neural networks are thought to be simulations of the human brain. But comparing the brain to an artificial neural network is like comparing the human heart to the handle of a pump. Dr. Andrew Knox and Dr. Robert J. Marks discuss the brain, aging, and neurology.
This part starts at 00:04 minutes. A partial transcript and additional resources follow.
Robert J. Marks: I have to ask you a little personal question. Do you work with brain-damaged children? Man, I would find this difficult. I have a small child who has epileptic seizures and brain damage. I don’t know, you’re going to have a hard time just leaving this at work and not taking it home, but your profession has developed a kind of rhino skin and you have to separate the medical side from your personal feelings. Yes. Do your experiences sometimes haunt you after your work?
Andrew Knox: Well, sometimes they do. In fact, one of the great things about doing epilepsy is that there is a broad spectrum of what epilepsy looks like. So there are kids who have frequent daily seizures that cause all sorts of problems.
But there are many other children who have a few seizures in their lives and then disappear after a few years. I find this useful even if it’s just dealing with fatigue or taking care of a patient. It is a pleasure to work with those families, even in difficult cases. I met some wonderful people that way.
I think one of the great things about being a doctor or part of medicine is being with people and helping them get through the times. This is an important thing you can do for your patients, even if there is no cure available for their particular medical problem.
Robert J. Marks: In a way, it’s like a ministry for you, right?
Andrew Knox: yes.
Robert J. Marks: Well, you are a neurologist. What do neurologists think of the brain? Is there a particular way of looking at the brain?
Andrew Knox: Neurologists are usually primarily interested in thinking about brain hardware. There, parts of the brain can be seen either in imaging studies, pathology under a microscope, or studies looking at brain wave activity. We are concerned with low-level brain problems.
Psychiatry and psychology usually approach the brain from the perspective of the mind — not what is happening in the physical substrate of the brain, but what is going on in people’s thought processes and how those thought processes work. Well, obviously there is overlap between the two.
Robert J. Marks: yeah that’s what i meant to ask. There must be an overlap between the two. So what is it?
Andrew Knox: That overlap is, in some respects, not yet fully understood. It can come out in different ways. For example, if we think about depression, certain brain structures are associated with depression. There are neurotransmitters that have been implicated in depression. Indeed, there are cases of depression where treatment with specific medications that deal with neurotransmitters can help improve or eliminate the problem.
Robert J. Marks: Now, let’s drill down a bit. Could you define and talk about neurotransmitters? What are they and why are you interested in them?
Andrew Knox: At its basic level, the brain is made up of neurons, cells that use electrical signals to integrate information and communicate with each other. Then there are other supporting or glial tissues. Neurons communicate with each other through neurotransmitters. There is a structure called a synapse, which is the connection between the output from one neuron and the input to another neuron. They communicate via tiny chemical messengers. When I say neurotransmitters, that’s what I’m referring to: the substances that neurons use to communicate with each other.
Robert J. Marks: He said he felt his brain slow down as he got older. Are my neurotransmitters like a little knob down as a function of age?
Andrew Knox: Yeah, you could potentially say that. Certainly for a child, looking at how the brain develops in her first 18 years of life shows that a child’s brain is actually building more synapses. So, in her first decade, there are more and more connections between different neurons. A child may actually have twice as many neurons as she does in a typical adult.
Robert J. Marks: very?
Andrew Knox: yes. And part of maturation is actually getting rid of superfluous synapses.
Robert J. Marks: So aren’t these synapses used in some way?
Andrew Knox: yes.Your brain develops its structure, or meaningful pathways or communication between neurons in real time. There’s probably a good analogy for the way you think [artificial] neural network. When you start using your neural network, train it. And as you train it, some ties get stronger and some get weaker.
The brain goes further and actually removes some of these connections entirely. It likely improves cognitive function when you are in the childhood range.
Robert J. Marks: That’s interesting. Artificial neural networks had a process called pruning. If there are neurons sitting there doing nothing, they will eventually be algorithmically removed from what is going on. Suppose it’s the weather. It has nothing to do with whether you’re talking about cats or dogs. So it happens to children…
Andrew Knox: It’s part of normal brain development, probably for the exact same reason you said. As you get older and experience, your brain narrows down to the most beneficial connections.
Robert J. Marks: Now, will the removal of neurons continue, or will it plateau at some point?
Andrew Knox: it’s flat. I’m also not talking about getting rid of neurons. I’m just talking about removing some of the connections between different neurons. So, by and large, the number of neurons stays roughly the same.
Robert J. Marks: Is that so. interesting. Now, we’ve talked about the difference between neurology and psychology, and you characterized it as hardware versus software, right? Let’s talk about how it breaks. That’s a pretty strong statement. “Break” is different from “slow down”. How do brains break?
Andrew Knox: There are many ways to break the brain, let’s look at some typical examples. I think it also gives us some good insight into how neurologists think about the relationship between the brain and the mind.
Most people think of neurology as having emerged from the study of stroke. This is a typical problem that usually appears later in life. But there are also children with stroke.
Andrew Knox: The basic idea of a stroke is that something blocks blood flow to a particular part of the brain. When that happens, brain tissue in that particular area dies. Neurologists who treated stroke patients noticed that many patients presented with the same set of symptoms. [they] We found that brain tissue was lost in certain areas. They found a good correlation between the loss of brain tissue in specific areas and the symptoms patients may have.
Next: What if my child has a stroke or signs of dementia?
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You may also want to read: A neurosurgeon on why some people only work with one half of their brain. The research results are encouraging and point to two big truths. First, the mind is not the brain. Second, people tend to view the mind-brain relationship in terms of cultural concepts that are important to them.
