The human brain is a mystery, but it is also one of the mysteries that have generated the most interest throughout history.
After all, it has been known for millennia that it is in him that thoughts, feelings, subjective sensations and self-awareness arise. In addition, this set of organs is so complex that until recently those who wanted to study could only do so passively and indirectly, that is, examine the brains of people who have already died and try to relate the symptoms. that this person was expressing. the anatomy of its nervous organs.
What technologies are used to study the brain and nervous system?
This had obvious drawbacks: this type of information also could not be contrasted with what was observed in the person’s behavior in real time (which meant among other things that useful data could not be obtained for treatment of patients). study brain activity, present only in living people. The latter is very relevant, since the brain is partly formed by the activity it contains: the characteristics of the dynamics of the nervous functioning of each modify the anatomy of the brain.
Fortunately. today there are technologies that make it possible to study not only the anatomy of the brain of living and conscious people, But also its operation and activity in real time. These new techniques are encelography (EGG), computed tomography (CT), positron emission tomography (or PET), angiography and functional magnetic resonance imaging (fMRI). Below we will see the characteristics of each of these systems.
1. Electroencephalography, EEG
This was one of the first methods developed to “read” brain activity, that is, the electrical trigger patterns that pass through it. The technique is relatively simple, and involves leaving electrodes attached to the scalp of the person so that they pick up the electrical impulses they pick up just below to send this information to a machine. The machine collects this data and expresses it as lines and peaks of activity using a chart plotter, much like seismographs that measure the intensity of earthquakes. This activity log is called an encephalogram.
EEG is very simple and versatile, so it can be used to measure the activity of a few neurons or larger areas of the cerebral cortex. It is widely used to study cases of epilepsy, as well as brain waves from sleep, but because it is not very precise, it does not allow us to know exactly in which part of the brain these activation patterns begin. In addition, knowing how to interpret encephalography is complicated and requires good training and supervision.
2. Computed tomography, computed tomography
the computed tomography (CT)Unlike encephalography, it gives us a picture of the brain and its anatomy from different angles, but not of its activity. This is why it is mainly used to study the shapes and proportions of different parts of the brain at a given time.
3. Positron emission tomography or PET
This kind of tomography whether it is used to study brain activity in specific areas of the brain, albeit indirectly. To apply this technique, a slightly radioactive substance is first injected into the person’s bloodstream, which will leave a trail of radiation wherever it passes. Then, certain sensors will detect in real time which areas of the brain are those which monopolize the most radiation, which may indicate that these areas are absorbing more blood because, precisely, they remain more active.
From this information a screen recreates the image of a brain with the most activated areas marked.
the angiography it looks a bit like PET, although in this case some kind of ink is injected into the blood. In addition, the ink does not accumulate for a period of time in the most activated areas of the brain, unlike with radiation, and remains in circulation in the blood vessels until it is gone. , it therefore does not make it possible to obtain an image of the brain. activity and if of its structure and anatomy.
It is used in particular to detect diseased areas of the brain.
5. Magnetic resonance imaging (MRI and fMRI)
both the Magnetic resonance imaging like its “enlarged” version, functional magnetic resonance imaging, or fMRI, are two of the most popular brain study techniques in psychology and neuroscience research.
Its operation is based on the use of radio waves in a magnetic field in which the head of the person in question is inserted.
The limits of these techniques
The use of these technologies is not without drawbacks. The most obvious is its cost: the machines necessary for its use are very expensive, and to this must be added the opportunity cost of having reserved space for a clinic and having at least one highly qualified person who will run the clinic. process.
Additionally, information related to which parts of the brain are activated does not always provide too much information, as each brain is unique. This means that just because part of the cerebral cortex “turns on” does not necessarily mean that the part in charge of the X function has been activated.