Here’s your brain:
For the layman, it can be broadly described as a dense, complex network of neurons and the synapses between them. The whole structure is almost incomprehensibly complicated, but the basic parts are fairly easy to understand. Neurons are cells, which serve a function of receiving electrical signals from previous neurons in the network, and when a certain voltage threshold is reached – of ‘firing’ their own signal to the next neuron in the network. Synapses, on the other hand, are the structures, which are used by the neurons to send and receive these signals. So the oversimplified way we can imagine them as, is just tiny wires between the neurons.
It is arguably the most complex structure humans have ever had the chance to analyse. In comparison to our extensive knowledge about the biggest objects in the deep cosmos and the tiniest, near invisible, building blocks of matter, we know almost nothing about this gooey flesh sack, residing in our head.
Isn’t that weird? Why is it so hard to study this thing?
Well, first of all, and most obviously – cutting into it is generally frowned upon while it’s still functioning properly and waiting until it isn’t functioning anymore to tinker with it can only give us so much information, before we need better ways to gather data.
Luckily, there are many smart and creative people in the world, who are very good at gathering data about something, without ever needing to actually come in contact with the thing itself (see Astrophysics). These people have come up with a variety of subtle ways to inquire into the workings of the fleshy sack. Here’s a few of these methods:
- Electroencephalography (EEG)
As the neural network responds to a stimulus, a big number of neurons begin to fire in succession, each neuron excited by the previous one and so on. This cascade of electrical activity is what is commonly referred to as a brain wave.
Electroencephalography is the method of tracking this large-scale brain activity by simply placing a number of electrodes on the outside of the head and recording any electrical activity. This way we can form a broad picture of how our neural network responds to various stimuli and we can start to build our picture of associations of particular areas of the brain to particular emotions, senses, activities , etc.
- Computerised Axial Tomography (CAT Scan) and Magnetic Resonance Imaging (MRI)
I’m grouping both of these methods together, as they are different ways to achieve the same result – a 3D model of the brain. CAT Scans use a series of x-ray images of different ‘slices’ of the brain to form the 3D model, while MRI uses radio waves and strong magnetic fields to achieve the same effect, without subjecting the patient to harmful radiation.
- Positron Emission Tomography (PET Scan) and Functional MRI (fMRI)
PET Scans consist of the subject swallowing a tracer substance (normally a variant of glucose) and then tracking the way the brain uses this substance as an indication of its specific activity. fMRI is essentially a combined use of a PET Scan and MRI, to both show a 3D model of the brain and map onto it the current blood flow to its specific subsections.
- Freaky Accidents (No fancy name for this one)
In contrast to the previous high-tech methods, the simplest one is to just wait for chance to do our work for us. In rare cases people suffer from a brutal accident, in which a certain part of the brain suffers irreparable damage. In these cases, we can observe any changes to the subject’s personality and mental activity and infer the functions of the damaged brain section.A famous example of such an accident is the unfortunate fate of Phineas Gage:
A railroad worker from the 1800’s, who survived an accident, in which a large iron rod was driven completely through his head, destroying much of his brain’s left frontal lobe and causing a dramatic shift in his personality in the twelve remaining years of his life.
Armed with tools, such as the ones previously listed, and a vast knowledge of anatomy, biochemistry, molecular biology, evolutionary biology, some psychology and pharmacology, these awesome people called neuroscientists (even the name is awesome) work in one of the most interesting and practically impactful research fields in science!
To anyone who’s interest I’ve piqued – I highly recommend to further inquire into the subject, if you haven’t already, as it is a fascinating body of work, and I have barely scratched the surface of it. But be warned! If you are anything like me, you might become addicted to reading and watching lectures on the subject, as I certainly have for the past few weeks, but then again – what better addiction is there to develop than learning?