title: Differential gastric ulceration in rats receiving shocks on either fixed-time or variable-time schedules.
abstract: Research suggests that predictable electric shocks produce less stress than unpredictable shocks. In this experiment, predictability was manipulated by using fixed-time (FT, predictable) and variable-time (VT, unpredictable) schedules of shock delivery. Rats receiving 3-mA, 1-s electric shocks on a FT 45-s schedule developed less gastric pathology than another group that was administered identical shocks on a VT 45-s schedule. It is argued that this finding represents a more subtle effect of predictability than has been obtained heretofore.
mesh_terms: D000818:Animals; D004597:Electroshock; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D013276:Stomach Ulcer / Q000523:psychology*; D013312:Stress, Physiological / Q000150:complications*