Chris Smith
Appearances
Global News Podcast
Syria's new leader says armed factions will come under state control
This is what we call an observational study. So what you do is you don't randomise people to something and then see what happens to them.
Global News Podcast
Syria's new leader says armed factions will come under state control
You look at all the people doing different things and see what their outcomes are and it is subtly different because when you look at the rate of Alzheimer's disease across the population you can say well we expect this number of people in the population to get Alzheimer's disease.
Global News Podcast
Syria's new leader says armed factions will come under state control
Then you break them all up into what they do for a job and you see if any job is higher or lower than that average number. And taxi drivers, ambulance drivers, they turn out to be right at the bottom of the risk list. 1% compared to some occupations that seem to be associated with an 8% risk.
Global News Podcast
Syria's new leader says armed factions will come under state control
And you could say, ah, right, well, I'll go and be a taxi driver and I will immediately reduce my risk of getting Alzheimer's disease.
Global News Podcast
Syria's new leader says armed factions will come under state control
Now, that might be true, but actually, statistically, that might be a fallacy because what might be happening here is that people who are at low risk of Alzheimer's disease because of the way that their brain is wired up also happen to have all the right neurological attributes to be a really good taxi driver, store lots of spatial information, know their way between A and B incredibly well, and therefore having that sort of brain composition selects for being a taxi driver
Global News Podcast
Syria's new leader says armed factions will come under state control
and means you're at low risk of Alzheimer's disease. So we don't know if it's cause or effect. And you've got to be really careful about attributing cause when it's not causal, it's an association.
Global News Podcast
Syria's new leader says armed factions will come under state control
It does make a difference because about 24 years ago, Eleanor McGuire, who's a researcher in London, published a paper that got headlines all around the world when she showed that taxi drivers' brains do change in response to being a taxi driver. They actually looked at people who hadn't
Global News Podcast
Syria's new leader says armed factions will come under state control
and then had completed the knowledge, the amazing tests that taxi drivers in London have to go through to learn literally thousands of routes right the way across London. She found that this affected a region of the brain that we know is uniquely bound up with being able to find your way around and have a really good three-dimensional map of the world inside your head. That's the hippocampus.
Global News Podcast
Syria's new leader says armed factions will come under state control
One region of the hippocampus in these taxi drivers was bigger after they finished the knowledge.
Global News Podcast
Syria's new leader says armed factions will come under state control
Therefore, one argument is, well, if you can flex your brain in this way, in the same way that building muscles in the gym, if you build brain power by doing cognitively demanding tasks, perhaps that does mean you are at lower risk of developing certain memory-eroding conditions like Alzheimer's disease.
Global News Podcast
Syria's new leader says armed factions will come under state control
Against that theory is that Alzheimer's tends to, while it does start in regions like the hippocampus, this area I'm talking about, It actually is a global brain shrinkage, so it's harder to argue that flexing one bit of the brain more ought to then have a protective effect everywhere, which is why scientists are saying we're not sure if it's cause or effect.