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Isolation
Secretory system
Endurance
Otter
Otter
Vydrino
Vydrovaya the shrew
Blowing of the sowings
Breaking in
Visiting editorial staff
The out-of-town session of the law court
Viability
Overflow
Caused potentials
Calling production
Calling instrument
Abortion
Switch is electrical
Vykopochnye the forest instruments
Fillet
Vyksa
Redemption operation
Hatching
Vylcha
Vylchanov
Freezing the plants
Extinction
Extortion in
Soaking the plants
Freezing
Vfp

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Caused potentials

the fluctuation of bioelectric potentials in the surface electroencephalogram or into the records of the elec. activity of other formations of the brain, proceeding in response to the pulses, which enter through the ascending or associative nervous ways. They distinguish: primary v. p., or the primary answer (ON), with the short latent (latent) period, which appears 10-20 ms after pulsing. It is recorded in the limited zone of the crust representation of the irritated analyzer (for example, after the irritation of eye by the flash of light PO it appears in the occipital cerebral cortex in the form one- or two-phase fluctuation of biopotential, fig. y,A); in t about r and h n ye v. p., or second answers (V), with the large latent periods (from 30 to 200 ms) and the wider region of propagation (Fig. of y,B). IN they appear first in the same zone of the brain, that also ON, they are characterized by more complex form and multiphasic nature. Simultaneously either more lately are observed local reactions even more complex on the form VO in other points of crust - Vol. n., or even throughout the entire cortex of the cerebrum - generalizovannye reactions (Fig. 2).

Fig. 1. But - primary answer to the single elec. irritation of the skin. Active electrode above the somatosensory region, the second - in the frontal bone. Moment of irritation in the form of the distinct maximum. First phase - droop, the second - deviation upward. On the lower timing curve is - 10 ms B - second answer; record at a distance is several of mmot of focus max, activity of primary answer. (both records on the cathode-ray oscillograph.)

Fig. 2. Distribution of the caused potentials to the light on the regions of the hemispheres: points 1 - 7 (record on the chernilopishushchem electroencephalograph). Vertical line on the electroencephalogram - sign of irritation. Deflection of feather upward - strengthening electronegativity.

ON - the algebraic sum of initial changes of the biopotentials in the group of crust neurons in response to the first volley of pulses, which comes the crust from receptor along the shortest specific (lemniskovym) nervous ways. Reasons for the appearance of local IN - the trace processes, which are developed in the same crust neurons, and the propagation of excitation (its irradiation) along the associative nervous ways to the nearest and more distant neurons. It is considered that generalizovannye IN appear with pulse arrival into the cerebral cortex on nespetsifich. to nervous ways (from the reticular formation, limbich. of system).

The maps of representation in the cortex of the cerebrum of visual, auditory, skin and other receptors are created on the basis of registration PO. Appearance PO and IN is tightly connected with processing of obtained by organism information and closing the conditioned-reflex connections in the nervous system. Registration v. p. adapts in the clinic for refining the localization in the brain of path. process.

Lit.: R on and t b and to a. i., caused potentials of the cerebral cortex, in the collection: Contemporary problems of electrophysiological studies of nervous system, M., 1964; Kullanda k. M., the second bioelectric reactions of the cerebral cortex, there; Puchn certain l. M., electro-cortical reactions to the light in man, Novosib., 1967. E. A. zhirmunskaya.