Projection in surrogate decisions about life-sustaining medical treatments.

To honor the wishes of an incapacitated patient, surrogate decision makers must predict the treatment decisions patients would make for themselves if able. Social psychological research, however, suggests that surrogates' own treatment preferences may influence their predictions of others' preferences. In 2 studies (1 involving 60 college student surrogates and a parent, the other involving 361 elderly outpatients and their chosen surrogate decision maker), surrogates predicted whether a close other would want life-sustaining treatment in hypothetical end-of-life scenarios and stated their own treatment preferences in the same scenarios. Surrogate predictions more closely resembled surrogates' own treatment wishes than they did the wishes of the individual they were trying to predict. Although the majority of prediction errors reflected inaccurate use of surrogates' own treatment preferences, projection was also found to result in accurate prediction more often than counterprojective predictions. The rationality and accuracy of projection in surrogate decision making is discussed.     

The effects of applied tension on symptoms in French-speaking blood donors: a randomized trial.

Blood-donation-related symptoms such as dizziness and weakness discourage people from participating in this important health-related activity. Four hundred sixty-seven young adult, French-speaking blood donors were randomly assigned to (a) a condition in which they learned a possible preventive technique called applied tension and were asked to practice it from the time they got on the donation chair until they were just about to get up, (b) a placebo condition in which they learned applied tension and were asked to practice it from the time they got on the chair until the insertion of the donation needle, or (c) a no-treatment control condition. Donors assigned to the treatment condition reported significantly fewer blood-donation-related symptoms than did donors assigned to the other conditions and rated their likelihood of returning to give blood again as greater than did those in the no treatment condition. Among donors whose chairs were not reclined, participants in the treatment condition had significantly smaller heart rate reactions to blood donation than did those in the other conditions.     

Appraising the threat of illness: a mental representational approach

This article (a) describes a mental model underlying initial evaluations of illness signs and (b) reports an experiment demonstrating the model's utility by showing how the model represents evidence of defensiveness among people who test positively for a sign of illness. The model consists of a set of cognitive elements that people consider to evaluate the threat represented by a sign of possible illness. Seventy-two undergraduates were led to believe that they tested positively or negatively on a saliva test for a fictitious risk factor for a disease. In addition, half the participants were told about the existence of a simple preventive treatment for the disease, whereas the others were not. Subsequently the participants answered questions about elements of the threat-appraisal model. Analysis of their responses reveals evidence of defensiveness on several elements of the model. Those testing positively for the risk factor, especially those uninformed about its treatment, minimized threat by (a) increasing their estimates of the false-positive rate of the test, (b) decreasing their estimates of the seriousness of the risk factor, and (c) decreasing their estimates of the extent to which the disease itself is life-threatening. Applications of the model to actual illness threats and the relation between threat-related judgments and health-related behavior are discussed.     

The effects of culture and self-construal on responses to threatening health information

Objective: The current studies examined if cultural and self-construal differences in self-enhancement extended to defensive responses to health threats.

Design: Responses to fictitious medical diagnoses were compared between Asian-Americans and European-North Americans in Experiment 1 and between Canadians primed with an interdependent versus an independent self-construal in Experiment 3. In Experiment 2, the responses of Chinese and Canadians who were either heavy or light soft drink consumers were assessed after reading an article linking soft drink consumption to insulin resistance.

Main outcome measure: The primary-dependent measure reflected participants’ defensiveness about threatening versus nonthreatening health information.

Results: In Experiment 1, all participants responded more defensively to an unfavourable than a favourable diagnosis; however, Asian-Americans responded less defensively than did European-North Americans. In Experiment 2, all high soft drink consumers were less convinced by the threatening information than were low soft drink consumers; however, among high consumers, Chinese changed their self-reported consumption levels less than did European-Canadians. In Experiment 3, interdependence-primed participants responded less defensively to an unfavourable diagnosis than did independence-primed participants.

Conclusion: Defensive reactions to threatening health information were found consistently; however, self-enhancement was more pronounced in individuals with Western cultural backgrounds or independent self-construals.     

A controlled evaluation of paraspinal EMG biofeedback in the treatment of chronic low back pain

Sixty-six chronic low back pain sufferers were randomly divided into three groups. Following individual assessments consisting of psychological questionnaires, pain monitoring, and measurement of paraspinal electromyogram (EMG), one group received paraspinal EMG biofeedback and another a placebo treatment. The third group received no intervention. Two further assessments were carried out on all groups immediately after treatment and at a 3-month follow-up. All groups showed significant reduction in pain, anxiety, depression, and paraspinal EMG following treatment and at follow-up, but there were no differences between groups. A regression analysis failed to identify subjects' characteristics that predicted positive outcome in the biofeedback group. However, high scores on the Evaluative scale of the McGill Pain Questionnaire and high hypnotizability were significant predictors of positive outcome for the placebo group. It is concluded that paraspinal EMG biofeedback is not a specific treatment for chronic low back pain in a nonhospitalized population.     

Judging health status: effects of perceived prevalence and personal relevance

In this article, we show that people's evaluations of the seriousness of a health disorder are influenced by the perceived prevalence and personal relevance of that disorder. As part of a study ostensibly concerned with college students' health characteristics, 60 undergraduates were "tested" for the presence of a fictitious enzyme deficiency. The subjects discovered either that they had the deficiency (deficiency-present subjects) or that they did not have it (deficiency-absent subjects), and were led to believe either that 1 of the 5 people in the laboratory had the deficiency (low-prevalence subjects) or that 4 of them had it (high-prevalence subjects). As predicted, the low-prevalence subjects evaluated the deficiency as more serious than did the high-prevalence subjects. In addition, consistent with the view that personal relevance affects perceptions of health disorders, the deficiency-present subjects evaluated the deficiency as less serious than did the deficiency-absent subjects. The deficiency-present subjects also derogated the validity of the test ostensibly used to diagnose the deficiency compared with other subjects. Finally, the deficiency-present subjects requested more information about the deficiency than did the deficiency-absent subjects.     

The fundamentals of controlling chaos

The concepts of chaos and its control are reviewed. Both are discussed from an experimental as well as a theoretical viewpoint. A detailed exposition of the mathematics of chaos control is presented, with an eye toward implementation in computer-controlled experiments.