The Scalp Topography of Slow Vertex Response and Middle Latency Response in Human Subjects

Abstract

Scalp distributions of slow vertex response (SVR) and middle latency response (MLR) were studied in normal human subjects by computed mapping.
The 12 responses elicited by 12 electrodes on the scalp were analyzed automatically with Topography System 500 (Sanei Sokki Co. Ltd).
The peak to the baseline amplitude of each component of the responses were calculated, and the distribution of the relative voltage value spread upon the scalp was mapped on the CRT.
The maximal amplitude areas of P₁ components were tended to distribute over the fronto-central scalp regions.
The N₁ components were distributed maximally over the frontal head regions.
The P₂ components were localized upon the central regions.
The P₀ components were tended to dislocate to the contra-stimuli side from the central regions.
The Na components showed no stability.
The Pa components were distributed maximally over the centrofrontal regions.