Have you ever wanted to see inside of someone’s brain?
Well science has a few ways of reading your mind
hey guys Julia here for DNews.
The brain is made up of more than 100 billion neurons all connecting and firing, registering
information from the senses, forming memories, and making you, well you.
But how do we know what’s going on in there?
Back in the day it took something horrific, like an iron rod going through your skull,
for scientists to know what a part of the brain did.
An iron rod went through Phineas Gage’s temporal lobe in the mid 1800s, which forever
changed his personality.
Which lead scientists to discover that the temporal lobe might have something to do with
emotion.
Phrenology was BIG thing in the 1800s too.
Since they really couldn’t see into a brain without injuring a person, scientists believed
that the shape of your head related to traits.
Like a protruded forehead might mean you’re intelligent.
Phrases like “highbrow” and “lowbrow” can trace their roots back to phrenology.
But in the centuries since, we’ve become a little more advanced in the way we look
at the brain.
When we talk about the brain here on DNews we frequently mention MRI, or magnetic resonance
imaging technique, but what is it and how the hell does it see into the brain?
Well the technique is sort of new, it’s only been around for 20 years or so.
Like the name suggests the machine is basically a giant tube shaped magnet, basically as you
lie there, the machine aligns the hydrogen atoms in your body!
These aligned atoms give off very faint signals.
The machine uses these signals to take images of your insides in slices, kind of like slicing
a loaf of bread.
To see inside the brain, the machine takes advantage of the differences in magnetic properties
between oxygen-rich and oxygen-poor blood.
Basically when neurons fire, they need energy, they don’t store it themselves, so they
need a quick hit of energy from blood.
So this technique works on the idea that if you see an increase in blood flow to an area
of the brain, there’s increased activity there.
So scientists can see what part of the brain is working during different tasks like talking
or seeing.
However, it works too slowly to capture the changes in the brain that can happen in a
millisecond.
NIRS, also measures blood flow.
Near Infrared spectroscopy shoots a beam of light through the skull and measures how that
light changes on the way out.
The way it changes depends on how much blood there is in a part of the brain.
But other techniques can measure electrical activity in the brain.
EEG measures this through up to 256 electrodes placed on the scalp.
It’s an old technique, some form of the EEG has been around for over 80 years.
As neurons fire they give off electrical signals, which are picked up by the electrodes.
This way researchers can measure quick changes in the brain that can happen in the blink
of an eye.
While MRI’s are used more often these days, EEG’s are still used to diagnose conditions
like epilepsy.
MEG is kind of a mix of both.
It detects the magnetic fields created by electrical firing in the brain.
Basically when the brain’s neurons fire in a certain pattern, it creates small magnetic
fields detected by SQUIDS.
No, not actual squids.
I mean a superconducting quantum interference device.
But both of these measure activity at the surface of the brain.
The best we have for deep brain imaging for now is fMRI, or Functional magnetic resonance
imaging.
And in the past five years thousands of studies depend on the technique to discover things
like where emotions are registered in the brain and diagnosing mental illnesses.
WHICH IS SO COOL.
As neuroscientist Richard Frackowiak puts it, fMRI has paved the way for turning psychology
“into a biological science.”
Who knows what the future will hold?