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What Can Modern Neuroscience Really Do

This lesson is a part of an audio course Brain Science for Non-Scientists by Wilf Nelson

Modern neuroscience is an interesting beast, you will hear incredible statements like tomatoes curing Alzheimer's or Parkinson's but Alzheimer's and Parkinson's still exist, that MRIs can read minds and human-like AI is round the corner. But again human-like AI doesn't exist, and the courts don't use mind-reading MRIs; the courts don't even allow polygraphs known more commonly as lie detectors.

What is going on here? Well, the truth is some people get carried away. The results of the science aren't wrong, yes enzymes from lots of things have been shown to damage plaques and toxins which cause diseases in the brain, in a petri dish, in set conditions, not in a live human. Experiments can put people in machines that measure the brain states of people choosing to press the left or right mouse buttons and then use very complex stats to see if there is a difference between the two brain states before a person says they made their choice. There is a difference, that is a world away from airport scanners plucking thoughts out of your head. AI is technically the most complex challenge humanity has ever given itself, we don't understand our own consciousness, and yet we are trying to recreate it in machines that use silicon, not neurons. It would be an understatement to call that ambitious, but admirable and arguably doable.

This lesson is about what modern neuroscience can and can't do.

Modern neuroscience, as I explained in previous lessons, is bound by the machines we can use. MRIs study structure, but only down a couple of millimetres, that still includes thousands of neurons and as discussed EEG and MEG can study the brain millisecond by millisecond those machines can only locate brain activity to somewhere in a few centimetres, if at all because once you get deep in the brain, it becomes very hard.

Almost any study on the chemistry of the brain, on individual cells, or manipulating how brains work is done in rodents. Human research laws don't allow researchers to cut into human brains except for medical treatments, if in my own research I wanted to know whether a region was vital to processing regulation signals in the brain then I can't harm that region in humans but could apply to do that in rodents. Whether you agree or not, that is where modern neuroscience is right now.

Neuroscience also works on understanding the brain from one condition to the other. This is really important to understand. The brain is always active in one way or another, even when I study inhibited or quote-unquote shutdown regions they are still doing something but the analogy would be like a car just ticking over, it is still running. When you see images online of brains being lit up in some places and dark in others they are just computer images to make the stats programs easier to understand, you could if you wanted to show the entire brain as a set of numbers and it would mean the same thing. But that means we only understand the brain as either-or, how the brain really functions with every system interacting with every other system is just something we don't really understand. I also don't think that is a bad thing, what we know today is how different regions function, how they communicate, what they respond to and don't, and even how whole networks come together. The beauty of that research is enough for me; I look forward to the future but understand there are limits.

The other thing that modern neuroscience can tell us is how people do act, not how they should act. I get asked as a neuroscientist all the time why do people act this way or not, why to commit this crime, why do people not trust others more. I can give basic answers like humans are risk-averse, we are scared of loss, we also work in an in-group and out-group mentality, but ultimately neuroscience is describing behaviour, it passes no judgment. Even when I have interviewed people who study psychopaths, murderers, and violent criminals, there is no judgment, that is for the courts to provide. Our job is to study the brain, see how it works, and go from there. This sounds a bit weak, I know, but neuroscience and psychology have to study people are they are, not as we want them to be.

Let's say I want to know how people will handle their finances; neuroscience can put people in machines, offer money choices, and see how the brain responds and how people act. We know people value short term gain, even small gain, over long term gain, the brain reacts very strongly to immediate promises of wealth and even then gets scared when promises are threatened to be taken away. That means we should expect people will want to get rich quick schemes; we even know that from a sales perspective you should promise riches, scare the audience by saying they could lose something they don't even have, and then sell them a product. Again neuroscience has no opinion on if this is right or wrong, whether you should exploit neuroscience to sell products like this, but it is something modern neuroscience does understand. As scientists, we study the environment as it is, not as we want it to be, and move on.

This lesson has been abstract, but I wanted you to understand that modern neuroscience makes humble claims and doesn't try to change behaviour, only understand it. If you see flashy claims and moral panic, be wary.

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Wilf Nelson