As part of the BOLD study, we make model 3D brains from individual brain scans (as long as we don’t run into technical issues). Harriet and Saloni have just had their brains printed, and we’ve also received models for the first few children we scanned from the printers. The colours aren’t representative of our real brains, of course. The models are also smaller than our real brains – we print them to about 45% of actual brain size.
We think that brains are a little bit like faces – everyone’s is a little different, but we do expect some basic anatomy to be represented. What you see on these models is a representation of the cerebral cortex (the grey matter of the brain). It’s not very smooth, it looks a little bit like a walnut or the bark of a tree. Those different gyri (upward bumps) and sulci (the valleys in between) help to increase the area of the cortex that can fit in our skulls, so we can have more processing power.
These gyri and sulci also divide the brain up, and we know that different areas of the brain help us perform different functions. For example, the frontal lobe of the brain helps us with planning, reasoning, making decisions, but also helps us program and control our speech and limb movements. The parietal lobe’s function is somatosensation – a fancy word for dealing with touch and other sensations like pressure and pain. At the very back of the brain, the occipital lobe is responsible for vision. And just underneath the lateral fissure, the temporal lobe helps us makes sense of sound – so it’s a part of the brain the BOLD team is very interested in.
You can also see that the left and the right half of the brain are quite similar, but are not mirror images of each other. If you could open the model up, you would see the space the ventricles (fluid filled sacs in the brain) occupy – these help keep our brains light and buoyant. You would also see a bridge of fibres connecting the right and left half of the brain. This is the corpus callosum and helps the left and right half of the brain exchange information. As part of our project, we will examine if structural and functional differences between the left and right hemisphere are linked to variation in language ability.
If you get your brain scanned and printed as a 10-15 year old, you might notice that our brains look a little different from yours. If you peer very closely, you can see that our sulci are a bit deeper, and there is more space between the gyri. This is because as we grow older, the amount of grey matter we have actually decreases. We could be sad about this (we are!), but another way to think about it is that our brain decides which connections are the most efficient and then prunes away the rest. We also know that grey matter changes when we learn new information or skills, so our brains are constantly changing because of what we do.
If you want to know more about the brain and what it does, this page has lots of information.