Biomedical subjects

Andrew L Geers

Publications and source records attributed to Andrew L Geers.

6 recordsLinked to original sources

PubMed2005

Expectations and placebo response: a laboratory investigation into the role of somatic focus.

It has been theorized that expectations are an important causal determinant of the placebo effect. Placebo expectations, however, do not always yield placebo effects. In a laboratory study, we tested the hypothesis that one's level of somatic focus moderates the effect of placebo expectations on placebo responding. We also varied whether participants were told the placebo was a drug, could either be a drug or placebo, or was a placebo. The results revealed that individuals who thought they were taking a drug (i.e., unconditional expectations) reported more placebo symptoms when they closely focused on their symptoms. Individuals told they may or may not be receiving a drug (i.e., conditional expectations) did not differ from control participants regardless of how closely they attended to their symptoms. The findings have theoretical implications for expectancy models of the placebo effect as well as for practical research comparing the type of expectations held by individuals in clinical trials and clinical practice.

Adult↗

PubMed2005

Reconsidering the role of personality in placebo effects: dispositional optimism, situational expectations, and the placebo response.

OBJECTIVE: Prior investigations have failed to find reliable personality differences in placebo responding. The present study tests the hypothesis that personality and situational variables interact to determine placebo responding. METHODS: Optimists and pessimists were randomly assigned to one of three conditions. In the first condition, the participants were told that they were to ingest a pill that would make them feel unpleasant (deceptive-expectation group). In the second condition, the participants were told that they were to ingest a pill that would make them feel either unpleasant or was an inactive substance (conditional-expectation group). Finally, a third group was told they were to ingest a pill that was inactive (control group). RESULTS: Pessimists were more likely than optimists to follow a negative-placebo expectation when given a deceptive expectation, but not when given a conditional expectation. CONCLUSION: The personality variable optimism-pessimism relates to placebo responding when individuals are given a deceptive but not a conditional expectation. This suggests that personality and situational variables interact to determine placebo responding.

Adult↗

PubMed2005

Goal activation, expectations, and the placebo effect.

Motivational factors receive little attention in current theories of the placebo effect. Reasons for this position are reviewed, and an argument is made for reconsidering the influence of motivation on the placebo effect. The authors hypothesize that nonconscious goals alter reactions to a placebo expectation. Specifically, the authors predict that the placebo effect is most likely to occur when individuals have a goal that can be fulfilled by confirmation of the placebo expectation. The authors tested this notion in 5 experiments. The results demonstrate the role of motivation in the placebo effect across a variety of symptom domains and via 4 different goal activation techniques. Moreover, this moderating effect occurred for both positive and negative placebo expectations, across different placebo effect measures, and in brief laboratory experiments as well as in lengthier studies. It is argued that theories regarding the placebo effect should incorporate motivational factors.

Analysis of Variance↗

PubMed2003

Discerning the role of optimism in persuasion: the valence-enhancement hypothesis.

The valence-enhancement hypothesis argues that because of their active coping strategies, optimists are especially likely to elaborate on valenced information that is of high personal relevance. The hypothesis predicts that as a result, optimists will be more persuaded by personally relevant positive messages and less persuaded by personally relevant negative messages than pessimists. It also predicts that when the message is not personally relevant, optimism and persuasion will not be related in this manner. The results of 3 studies support these predictions and supply evidence against several alternative hypotheses. The possibility that the observed effects are not due to optimism but to the confounding influence of 7 additional variables is also addressed and ruled out. Implications are discussed.

Adaptation, Psychological↗

PubMed2002

Videotaped interrogations and confessions: a simple change in camera perspective alters verdicts in simulated trials.

Prior research has indicated that altering the perspective from which a videotaped confession is recorded influences assessments of the confession's voluntariness. The authors examined whether this camera perspective bias persists in more ecologically valid contexts. In Study 1, neither a realistic videotaped trial simulation nor potentially corrective judicial instruction was sufficient to mitigate the prejudicial effect of camera perspective on mock jurors' assessments of voluntariness or on their all-important final verdicts. Study 2 suggests that perhaps the best camera perspective to use is one that focuses trial fact finders' attention on the interrogator, as this particular vantage point may facilitate decision makers' capacity to detect coercive influences, which in turn could, in some cases, improve assessments of the confession's reliability.

Adult↗

PubMed2002

Illusory causation: why it occurs.

Considerable evidence indicates that people overattribute causality to a given stimulus when it is salient or the focus of their attention--the so-called illusory-causation phenomenon. Although illusory causation has proved to be quite robust and generalizable, a compelling explanation for it has not been empirically documented. Four social-attribution studies were conducted to test the hypothesis that illusory causation occurs because salient information is initially registered, or perceptually organized, differently than nonsalient information. The results provide considerable support for the notion that people's literal point of view affects how they initially perceive, or extract, information from an observed interaction, which in turn affects their judgments regarding the causal influence exerted by each interactant.

Adult↗