Research techniques in neuroscience are very important, especially if we take into account what we expect in the coming years of this science. Until not long ago, when neuroimaging techniques were just a dream, checking the reality of some theories about the nervous system was complicated / impossible.
In 1988, the Spanish physician Santiago Ramón y Cajal described the morphology of neurons through a complex staining system. Since that time , several milestones in neurobiology have occurred, such as the discovery of the electroencephalogram (EEG) or the classification of the biological rhythms of the brain.
What is a neuroscience research tool?
Neuroscience research tools are devices that allow studying the nervous system. So- called neuroimaging techniques are used for both clinical and academic purposes. Thus, these tools allow the nervous system to be approached from four approaches :
- Functional : describes the functioning of the nervous system, for example, through the flows or the degree of activation of various areas.
- Structural : they provide anatomical information about the brain or other structures of the nervous system.
- Electrical : techniques that provide information about the electrical activity of the nervous system.
- Stimulation : tools based on non-invasive stimulation of the brain.
Structural neuroimaging techniques
Among the structural techniques specialized in providing anatomical information, the most basic and used is radiography. This technique consists of the emission of X-rays ; Depending on the density of the tissue, it causes a different image to be projected onto the photographic plate. Finally, we have two types of X-rays:
- Common X-ray. Only X-rays are used. Commonly used to obtain information from the bones that surround the nervous system, in case of fractures.
- Contrast X-ray. It is used with the same X-ray method, but entering a catheter through the femoral artery. This hyperdense contrast allows to detect vascular alterations.
Computed axial tomography
We are talking about the famous tube-shaped scanner. This technique is based on the emission of X-rays from different directions, giving a more finished image and at different cutting levels. It is a fast and low-cost technique that allows the detection of tumors, aneurysms and hemorrhages. On the other hand, the radiation emitted is not good for the body and its definition is not as high as that of other techniques.
This research technique in neuroscience allows to collect images of the interior of the body with high resolution and safely; one of the few precautions that must be taken when using it is that it is incompatible with metal implants. It is based on the phenomenon of nuclear magnetic resonance, where the device records the radio frequency signals emitted by hydrogen atoms, previously subjected to a magnetic field.
Hydrogen atoms are present in large quantities in the body, so it is a high-resolution technique and without harmful effects by not using radiation. On the other hand, it has a high cost.
It is a tool that uses magnetic resonance imaging to evaluate the functioning of white matter beams. These are largely made up of water, and are responsible for carrying nervous information at high speed, since they are mainly myelinated axons. In this way, the technique allows to evaluate the subcortical structure of the brain, being able to detect neurodegenerative diseases and epilepsy.
Functional neuroimaging techniques
They are the research tools in neuroscience, which allow to detect changes in brain activity in vivo. They are usually used to assess cognitive processes in conjunction with the functioning of their anatomical correlates.
Positron emission tomography
This technique is based on the introduction of radioactive substances into the bloodstream. Cells with high metabolic activity absorb this substance. In this process, the isotopes that emit positrons cancel out when they combine with electrons, generating electromagnetic energy, which is captured by the device.
It is a widely used technique to detect brain tumors, since they tend to have a higher metabolism. In turn, it also serves to detect neurodegenerative diseases. In the case of Alzheimer’s, for example, the degeneration of cells will cause not as much substance to be absorbed and the image will differ from that of a normal brain.
Single photon emission computed tomography
Recording technique similar to the previous one, only that it uses gamma radiation, produced by an isotope directly from within the body. So, this technique also requires a receptor, through which an image will be generated, which highlights the different degrees of brain activation in colors.
Functional magnetic resonance
It consists of an MRI, but where at the same time some cognitive activity is carried out. It is based on the fact that the neurons involved in a mental process will need more energy and therefore more oxygen from the blood. When we perform a mental task, the consumption of oxygenated blood (which has magnetic properties) increases. So then, this activity is recorded by the device. Despite having a high cost, it makes it possible to locate cognitive functions in the brain.
These techniques allow the electrical activity of the brain to be recorded . Among the most outstanding we can list:
- Electroencephalogram. System that records the electrical potentials of the brain and therefore the type of wave and frequency in which it is working.
- Electromyogram. Technique to evaluate the electrical activity of the muscles. It is used for the exploration of the peripheral nerves.
- Electrooculogram. Muscular electrical recording of eye movement, used to distinguish the phases of sleep.
Brain stimulation techniques
These techniques allow influencing brain activity through two types of stimuli:
- Magnetic : With transcranial magnetic stimulation, a current is safely induced in the brain. This induction is achieved by a flow of current that passes through a coil and generates a magnetic field.
- Electrical : a low intensity current is applied through electrodes located on the scalp. This induction causes changes in the excitability of neurons in the cortex.
These forms of stimulation usually reach only areas of the cortex. They are mostly used to identify mental processes, as well as to create virtual injuries. Its application to improve performance or treat disorders such as phobias, is still under investigation and should not be applied in people with epilepsy, implants or pregnant women.
The importance of neuroscientific research techniques
Diseases that affect the nervous system often have serious consequences. Detecting a tumor or hemorrhage early is of the utmost importance to increase the chances of survival. Likewise, detecting a neurodegenerative disease in its early stages is the key to trying to postpone symptoms.
On the other hand, scientific progress has allowed us to delve into brain function. For example, it is currently possible to compare the brain of a depressed person with that of a normal person, obtaining functional differences associated with the symptoms. In the same way, we can identify the brain areas and processes corresponding to such a particular function, such as attention.
Arzy’s experiment, ghosts are in the brain
Arzy’s experiment is based on demonstrating the scientific nature of some hallucinatory phenomena, through electrical stimulation of the brain.