Bilateral symmetry of the time course of early facilitation of the Hoffman reflex

Abstract

The time course of early facilitation of the Hoffman reflex by a preliminary stimulus that preceded the reflex-eliciting stimulus by 2–17 msec in 1-msec steps was determined separately for the left and right legs of normal male subjects. The time course of recruitment and decay of facilitation was identical for both sides, showing that the asymmetrical temporal processing that has been reported does not extend to a simple neural network in the spinal cord. The results show the early facilitation in more detail than has been reported previously.