Effects of the Amount of Required Coping Response Tasks on Gastrointestinal Lesions in Rats

Abstract

The effects of the coping response on gastrointestinal lesions by changing the values of fixed-ratio (FR) schedule for the coping response task in freeoperant avoidance situation over 24 hrs were studied. In FR 1 or FR 2, experimental animals which could control electric shock to avoid or escape by pushing a flapper only once or twice developed less severe gastrointestinal lesions and body weight loss than yoked animals which received the same amount of shocks but could not perform any coping responses. In FR 5 or FR 8, however, the experimental Ss developed more severe stress pathology than the yoked or control Ss. These reversal effect show that the interaction between controllability of experimental environment and the amount of required coping response task plays an important role, which seems to support Weiss's ulcerprediction model.It is well known that" psychosomatic" diseases, such as gastric ulcers, essential hypertension and coronary heart disease are related to emotional stress (anxiety, fear or conflict). Many studies have been conducted to clarify the relationships between psychological stress and gastrointestinal ulcers in animals.Brady (1958) and Porter, Brady, Conrad, Mason, Galambos, and Rioch (1958) previously reported that the experimental animal, or the "executive " monkey, who could avoid an electric shock by pressing a lever under Sidman avoidance schedule, developed duodenal ulceration, and that the control animal which received identical shock experiences developed no ulceration. Brady and his coworkers concluded that responsibility for the fulfillment of the lever-pressing shock termination produces gastroduodenal ulcers while shock alone does not.However, the validity of Brady's experiment could he questioned. First, the monkeys were not randomly assigned to experimental and yoked control groups. In each pair, the subject which acquired the avoidance response first was chosen as the executive. Such a method of selection was not proper according to Sines, Cleeland and Adkins (1963) who found that rats which were susceptible to ulcers learned an avoidance response faster than normal controls. Second, in Brady's experiment the ulcer was produced only under the condition in which the monkeys worked on a cycle of an alternating sixhour avoidance and six-hour rest schedule. Animals exposed to either a 1 hr or 3 hr work-rest schedule did not develop ulcers. Third, some investigators who had attempted to replicate Brady's results have

Sense of Control in Late Life

“…It is likely that the consequences will be similar to those that have been found for traditional perceived control measures (e.g., locus of control, mastery, and self-efficacy). Perceived control is consistently shown to have health benefits for individuals across the life span (Schulz, Heckhausen, & Locher, 1991), and the early experimental studies convincingly demonstrated its linkage to autonomic reactivity and catecholamine levels, suppressed tumor rejection, and increased tumor growth and gastric ulceration (Bandura, Reese, & Adams, 1982; Sklar & Anisman, 1979; Tsuda & Hirai, 1975; Visintainer, Volpicelli, & Seligman, 1982).…”

Predictable and unpredictable shock: Behavioral measures of aversion and physiological measures of stress.

“…Although the mechanisms involved in ulcerogenesis are not clearly understood, the development of gastrointestinal lesions is sensitive to behavioral and emotional factors (cf., Weiss, 1977). Immobilization (e.g., Brodie, 1963;Brodie & Hanson, 1960;Selye, 1936), conflict (e.g., Sawrey, Conger, & Turrell, 1956;Sawrey & Weisz, 1956;Weisz, 1957), and absence of control (e.g., Tsuda & Hirai, 1975;Weiss, 1968,197 la, 1971b have potent effects on ulcer development. Therefore, investigations examining the effects of predictable and unpredictable shock on gastric pathology must attend carefully to these variables.…”

The Physiological Mechanisms of Motivation

“…In an experiment following up on Weiss's study of the effects of a coping response on stomach lesions, Tsuda and Hirai (1975) found that, compared with helpless yoked control rats, those that could escape the electric shock by a single bar press had fewer stomach lesions, but those that had to press the bar 10 times in order to escape had more lesions. From this, the formulation represented in Figure 14-10 would have to predict that the latter group would show more fear than their yoked controls by all of the other measures, including the CER and learning and performing a response to escape from the apparatus.…”