Effects of coping behavior on gastric lesions in rats as a function of the complexity of coping tasks.

In fixed ratio (FR) 2 coping task condition, experimental rats which could avoid and/or escape shock by emitting a disk-pulling operant response developed less stomach ulceration than did yoked "helpless" rats which had exactly the same shock but which had no control over shock. In variable ratio (VR) 5 coping task condition, however, the experimental rats developed more lesions than did the matched yoked rats. Neither the VR 2- nor the FR 5-experimental group was significantly different from its yoked group. Ulceration of non-shock control group was negligible compared to experimental and yoked rats in each of the four coping task conditions. The level of a complexity or difficulty of coping response tasks required has a detrimental effect on ulcerogenesis for "coping" experimental rats. The effectiveness of a coping behavior covaries with the nature or ease of the coping tasks in a stressful situation.