Behavioral kinetics: dynamics of the unconditioned response to footshock.

The purpose of this paper is to present an instrument and behavioral assay for monitoring the unconditioned response to footshock in the rat. The instrument provides measures of the total force exerted by a subject in response to a footshock, the duration of the subject's response, and the subject's latency to respond to the stimulus. The assay is developed to minimize the error variance inherent in behavioral measurements. In the second part of this paper, the relationships between the response and the physical parameters of the stimulus are investigated. The total force exerted by a subject, and the duration of the subjects response are linearly related to the multiplicative interaction of stimulus current and stimulus duration. The subject's latency to respond is curvilinearly related to stimulus current alone. The form of this relationship is hyperbolic. These results are discussed in the context of the measurement of behavioral and psychophysical processes in psychobiological research.