Evoked potential tomography

The evoked potential is brain activity upon presentation of a repetitive sensory stimulus. You can compare how it changes in the process or under different stimuli. This is a multichannel method for recording brain activity further averaged.

This method has its limitations and advantages. The method of averaging is used. Used since the 50s. This method can find out the familiar and unfamiliar information, information that is significant or insignificant. You can fix the “waiting wave” (cnv, e-wave) for a stimulus that repeats after a fixed time. Click - wait wave - flash - click on the button = study of the formation of the reaction. Under normal conditions, a waiting wave is formed in a depressed person, and in extreme conditions in a depressed person, a waiting wave is suppressed - this is a test for pathology. The test is also used to test children with voluntary attention problems. Correction is carried out with the help of BFR There is still potential caused by events.

Tomography - the study of natural radiation (MRI) or from the introduced positrons (PET).

The founder of PET - Pozdner, the disadvantage - isotopes should be made nearby, since the isotope lives for 30 minutes. Different isotopes can be introduced which are akin to the body. With their help, you can identify various pathologies, but to study the dynamics you need a long time. They shoot a picture before the task and after it has been received and the beginning of the solution. Then the results are compared and subtracted from one another.

MRI is a more affordable and compact method, but also expensive. Diagnostics takes less time and gives more detailed information. This method can be used to diagnose a conflict detection system and a smoothing system. fMRI allows you to see the dynamics of the process. It is very important in the preoperative diagnosis to determine the individual location of the various zones.

Detection of neural and multi-neuron activity — implanted or injected microelectrodes into the brain — helps to find foci of arousal in epilepsy and Parkinson's disease. Registration by 1 electrode of several electrodes is a multi-neuron method. The hemodynamic signal reflects the dynamics of the change in the ratio of oxygen and oxygen-free blood in each area, which allows detecting areas that consume oxygen normally, increased, decreased, and hence the activity of neurons in these areas. Research methods correlate among themselves - fMRI, neural activity, EEG.

Neural networks are very specialized - one for the perception of certain stimuli (detectors), the other for motor acts (command). The brain is organized difficult, but very carefully and specialized.