Abstract: | Five experiments are reported which attempt to eliminate two possible sources of reinforcement in one-way avoidance learning: a period of escape from aversive apparatus cues and the termination of the warning signal (WS). A “brief escape”/one-way avoidance procedure was developed to minimize the time rats spent away from the shock box. It was found that, although prolonged escape from shock box cues contributes to the acquisition rate of one-way avoidance, it is not essential for relatively rapid acquisition to occur. It was also found, in agreement with earlier evidence, that WS termination makes no discernible contribution to learning in the one-way situation. Thus, neither source of reinforcement appears to be necessary for acquisition. At this point, one may argue either that reinforcement is not necessary for rapid one-way avoidance acquisition e.g., Bolles' 1972 species-specific defense reaction hypothesis (In G. H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 6). New York: Academic Press, 1972)] or that there are other sources of reinforcement. As an example of the latter approach, a consummatory stimulus reward hypothesis is advanced. |