Abstract
Rats received shock that was predicted by either a light signal alone, light-tone complex signal or no signal. In the light signal alone and light-tone complex signal conditions, experimental rats which could avoid and/or escape shock developed less gastric ulceration than did yoked “helpless” rats which had exactly the same shock but had no control over shock. In the non-signal condition, however, the experimental rats did not differ from the matched yoked rats. Ulceration of non-shock control rats was negligible as compared to experimental and yoked rats in each of the three warning conditions. Presence or absence of a safety signal has an effect on ulcerogenesis. The light signal alone condition was effective in reducing ulceration for “helpless” rats as well as rats which could control shock. Thus, the effectiveness of a coping behavior depends on the reliable prediction of shock in a stressful situation.