[Motor components of "caudate arrest"].

In chronic experiments on 4 defense-conditioned dogs maintaining a certain posture, the analysis of motor components of the "caudate arrest" (induced by high-frequency stimulation of the caudate nucleus) and their comparison with the characteristics of the myographic and motor components of normal cessation of the legs (i. e. in absence of the conditioning signal), showed the "caudate arrest" not to be a model for arrest of a voluntary movement. The caudate nucleus seems not to be involved structurally in the instrumental defense response but to belong to a parallel system controlling all stages of the response.