An Electromyographic Study on the Progress of Training for the Forearm-Lifting Response in the Dog

Abstract

Five dogs were subjected to the forearm-lifting training every day, except Sunday. A response stimulus was given in a simulated manner of the actual training procedure. Electromyograms were recorded from the biceps brachii muscle in the responding arm every 3 or 4 days during the progress of training. Premotor time (PMT), or the latency of sustained potentials, became obviously reduced and stabilized in all the dogs as the training advanced. The mean PMT ranged from 119 to 358 msec in the well-trained stage. Sustained potentials were often preceded by sparse potentials, the latency of which was designated the preceding potential latency (PPL). PPLs were highly variable and ranged from 9 to 1135 msec. They seemed to be divided into three groups: the first group having a mode at 15 msec, the second at 75 msec, and the third exceeding 150 msec. Based upon experimental results obtained under the sensory elimination, it was considered that preceding potentials of the second group primarily depended upon the auditory input and those of the third group upon the visual input. Thus, the dependence of the motor program for the forearm-lifting response on the sensory input seemed to have changed from the visual to the auditory input as the training advanced. In addition, the aptitude of individual dogs for training could be evaluated from the characteristics of the response.