The proposed approach is based on registering radiation features from the studied head surfaces reflecting the activity of the corresponding parts of the human brain. A person receives short low power light pulses with various frequencies at certain areas of the head. This light pulse is partially reflected from the surface and partly enters the tissue, where it starts to dissipate and absorb. The photons are repeatedly scattered on the optical inhomogeneities of the tissue and partially return back to the surface. The deeper the photons entered the tissue, the later and the smaller their proportion will come out. These photons can be registered with a photosensor, we can study the distribution of the released photons in time, and thus restore the optical (scattering and absorbing) properties of tissues at different depths. Since any biological tissue is not completely transparent, light will be partially absorbed. However, absorption is not critical in soft tissues, and the scattered fraction is quite large. This can be illustrated by shining a laser point through the palm of your hand in a dark room: you will see from the back of the hand that the light comes through it, while there will be noticeable darkening in the place of bones, demonstrating that light easily passes through a few centimeters of soft tissue. The skull is a more complicated object, but it can also be translucent since the skull is a porous medium rather than a solid barrier. A significant proportion of the photons will be absorbed, but the equipment is able to register a significant reflected component. For example, a milliwatt laser produces about 1016 photons per second. Even if only one-trillionth part of the photons are reflected, we will get 10 thousand photons per second, and a photo sensor is capable of registering this amount. Thus, it becomes possible to determine the activity of different zones of the human brain.
Let us describe a simple but real experiment on a human. The patient performs a simple motor task (taps the finger on the table), and an optical transmitter with a sensor installed opposite the left motor area of the cerebral cortex (which controls the movements of the right arm) try to see the brain manifestations of this action. Indeed, there will be clear distinctions between cases when the patient taps the finger of the left arm, the right arm, or does not tap at all, and also whether he has certain brain dysfunctions. In practice, for each frequency of the visible, infrared, and UV range, the rhythm frequencies, amplitude, waveforms, and topography will be calculated. It is assumed that each such "rhythm" corresponds to a certain state of the brain and is associated with certain cerebral mechanisms.
Devices recording optometric rhythms – optorhythmographs – have 4 or more channels and allow simultaneous recording of optorhythmogramms (ORGs) of a number of vascular regions. ORGs are recorded by fixing the sensors to the head surface.
ORGs have features depending on the patient age, and this is taken into account. Special functional tests are used during investigations to distinguish between functional and organic changes. We plan to use the Stange tests (maximum respiration delay), nitroglycerin test (in small doses, sublingually), head rotations, and body position changes. Sharply arising shifts of arterial pressure will be reflected in the ORGs by a change in the tone and the level of pulse blood filling, which will also be taken into account when analyzing the curves. The scientific novelty consists in registering radiation in the optical range from the surface of the human head, analyzing the topology of this radiation, as well as the corresponding rhythms at each of the optical frequencies. This allows us to obtain the most complete integral characteristic of the way the human brain is functioning at various levels of its organization. The practical novelty is in the mobile and fast nature of the registration, as well as in the increase of opportunities and information in registering functional states of the brain for assessing dysfunctions and pathologies, and for assessing the adaptive reserves of sportsmen. In addition, the methodology will allow to objectify the process of professional selection. Another application is the use of technology as a method of controlling a computer and electronic communication devices by consciously changing the mental activity of a person.