The contingent negative variation and the excitability of the spinal monosynaptic reflex

Abstract

A method is described which permits simultaneous measurement of changes in slow electroencephalographic potentials (Contingent Negative Variation, CNV) and the excitability of the spinal monosynaptic arc (H reflex) during the foreperiod of a simple reaction time experiment. Data from 11 normal subjects show that during the development of the CNV there is an augmentation of the amplitude of the H reflex. It is suggested that the 2 phenomena are controlled by a common subcortical structure.