Latent periods of the components of evoked potential.

Abstract

1. The generally accepted view on components of the evoked potential (EP) of the cerebral cortex as surface-positive and surface-negative waves is unsatisfactory: the information obtained from the layerwise [1] and synchronous layerwise leads [2] is used insufficiently, the EP profile proves to be a function of time, some components are indistinguishable on the cortex surface, and it is difficult to determine the total number of components and estimate their latent periods. I propose to transform the multilead recording of the EP (a set of curves that begin simultaneously) into another system of curves beginning at different moments. In this case, a time-independent normalized profile of the EP is constructed for each new curve. Let us call the product of the new time function and the corresponding profile a linearly independent component. The sum of linearly independent components is the EP to be measured. 2. Assume that the EP is recorded using n electrodes, the centers of the working surfaces of the electrodes being located at points x i of the cortex ( i = 1, 2, …, n ). Then, after each stimulation, n time functions V i ( t ) that have emerged at the moment t 1 are recorded. In other words, the latent period of the functions V i ( t ) is t 1 . The basic mathematical model of the EP is a sum of components W s ( t ) :