A strategy for facilitating post-treatment weight maintenance was examined. Subjects were matched for age, sex, and amount of weight that they desired to lose and were then assigned to one of two groups. Both groups were under contracts and had individually designed self-control programs for weight loss, but subjects in the experimental group lost weight in small steps and subjects in the control group lost weight continuously. The experimental group was predicted to have better weight maintenance after treatment because of a greater number of reinforcements for weight loss. Two-month follow-up data was obtained on the ten subjects who completed the study, and the experimental group was found to have regained significantly less than the control group after treatment ended. The implications of these results for obesity research are discussed.

The investigation sought to examine resistance to extinction (Rn) as a function of previous experience with downward shifts in reward magnitude. It was suggested that previous research conducted within the framework of the Spence-Amsel frustration hypothesis and the sequential hypothesis failed to administer sufficient postshift trials to adequately establish the relationships that may exist. Under one condition, four groups of rats received twenty extinction trials following forty postshift trials. Under another condition, four groups were extinguished following eighty postshift trials. An inverse magnitude of reward effect occurred in the preshift phases, however, which prevented an adequate analysis of either the shift or the Rn data, This unexpected effect was discussed within the framework of Black's incentive-motivation interpretation of reinforcement.

Human immunodeficiency virus (HIV) can result in posttraumatic stress disorder (PTSD) as events related to illness act as traumatic stressors. This study tested some basic hypotheses of Sewell and Cromwell's personal construct model of PTSD in HIV+ women both with and without diagnoses of PTSD. Trauma-related constructs of HIV+ women with PTSD with HIV+ non-PTSD controls at varying stages of illness were compared. The elaboration, rankings, and valence of trauma-related constructs were examined using the Life Events Repertory Grid (LERG) procedure. Findings provided evidence that a clinical diagnosis of PTSD in women was not associated with the degree of construct elaboration. These findings may imply a qualitative difference in cognitive processing of social stressors and violent stressors.

A procedure in which the S- was prevented from being responded to, by electro-magnets, was used to establish color discriminations. The procedure was modified in Situation 1, to include the prevention of responses to the S+ if the S- was responded to first. The original procedure and modified procedure were used in Situation 1, with only the modified procedure being used in Situations 2 and 3. The procedure of reinforcing responses to the S+ and extinguishing responses to the S-, through nonreinforcement, was used in Situation 4. Data recorded consisted of the number of trials, the number of reinforcements, and which stimulus was first responded to. Criteria for the acquisition of a discrimination was 100 first responses to the S+. Results indicated that the modified procedure was much more effective in establishing the discriminations, than the original procedure or the procedure of reinforcing responses to the S+ and extinguishing responses to the S-. The modified procedure enhanced the establishment of stimulus control, reduced the number of errors and eliminated stereotyped responses.

The present research has focused on an often-neglected segment of society—the aged. A number of phenomena which appear relevant to a study of aging have been discussed and the pertinent literature reviewed. Specifically, learned helplessness, depression, internal-external locus of control, and disengagement versus activity have been examined. The present research was divided into two studies. Study Number 1 has investigated internal-external locus of control in an elderly sample and related it to indices of activity and morale. Study Number 2 has extended Seligman's (1975) theory of learned helplessness to an elderly population and investigated the phenomenon in individuals with either an internal or an external locus of control. The locus of control construct (Rotter, 1966) and the theory of learned helplessness (Seligman, 1975) appear to have immediate relevance for the treatment of aging individuals. The present study suggests that exposure to controllable reinforcement may break-up or alleviate learned helplessness in elderly individuals.