Do you reckon this is possible?

I hear so much in psychology about the nature/nurture 'debate', and to anyone with half a brain it's obviously both of them.

But, I was wondering (naively thinking of a 24/7 MRI scanner fitted around one's head), if we could ever record someone's brain activity for their whole life or at least most of their development, and then find out what caused what and which experiences stunt this and which experiences cause that etc. etc.

The brain is so complicated to study, I figure it would only be possible to pinpoint its development through this type of development. You can't just cut up a brain and get all the answers, because you have no idea how it developed. If you could constantly monitor a brain's development, say in an animal to avoid ethical concerns, and correlate each growth with events in the animal's life, then you could figure out so much more about how the brain works.

It sounds very sci-fi; you'd have to have little invisible drones or something buzzing around its head, but mankind has approved that stranger things are possible.

MRI scans can't actually tell us much about brain activity. They can tell us which areas are active, but not really what's going on within them.

Basically we don't have the technological capacity yet, and may not for a very long time. There are 100bn neurons in the brain and we don't really know what's important. There's no existing technology that could monitor each one and transmit data, probably no technology with the capacity to record it all, and certainly no technology to crunch all the trillions of bits and make sense of them.

Even beyond our current limitations in brain imaging technology, it's not at all clear that slapping some sort of apparatus on someone's head and then setting them loose in the world could be very informative even in principle. The brain imaging technology itself is only half the story in brain imaging studies; the other half is very strict experimental control over what the subject does and doesn't do. Letting people do whatever they want while we scan them is basically the definition of a poorly controlled study.

In order to identify the neural correlates of some cognitive function, we have to compare the imaging data that we get from a subject when they are doing that task to the data that we get when they are doing a separate task which is exactly like the first task in every single way, except for the exact thing being studied. Further, we have to observe the subjects doing each of these tasks very many times consecutively in order to wash out incidental noise in the data. Then we use a sort of "subtraction" method, whereby we take the aggregation of all the experimental trials (trials where the subject is doing the thing of interest), and we subtract from that the patterns we see in the aggregate of all the control trials (trials where the subject is doing the matched task). What we are left with is a fairly good idea of which brain areas are active when the subject does just that one thing. (How useful that information actually is to us is another story entirely.)

A major problem with this naturalistic imaging data is that it would be extremely hard to identify "control tasks" that we could use to make sense of the data that we observed when the subject was doing the thing we are actually interested in. Imaging data is only informative relative to other imaging data; it's meaningless on its own. And when/if we could identify (purely through luck) a reasonable control task to use in examining a particular cognitive function, we are virtually guaranteed within this paradigm to get very noisy and low-quality data. Moral of the story: proper experiments are crucial.

I know the rough example I gave wouldn't cut it, but I was trying to emphasise more the technology part of it.

It's really sad in a way that it is so hard to develop. I don't even know why I am so intent on looking into the brain, because having access to 'too much' knowledge could lead to some pretty inhumane developments. I am always too paranoid about such technology being used for evil things like mind control, so maybe it's just as well.

I guess I need to understand how the brain works to make sure that it does. If you could prove the brain controlled the mind in 100% of its aspects then it would leave us with very clear philosophical answers to great questions. As for the actual practical use of the findings; like I said it's iffy but there will be ethical barriers to stop it and I hope we can use it for good.