Impairments in an early stage of the decision-making process in patients with ventromedial prefrontal damage: preliminary results.

Lesions of the ventromedial prefrontal cortex can result in a deficient decision-making behavior. So far, most experimental results in the neuropsychological decision-making research have been obtained with gambling tasks. Due to their high complexity, it is difficult to evaluate the underlying processes of the decision-making deficits. The aim of this study was to assess if patients with ventromedial prefrontal damage compared to patients with dorsolateral prefrontal damage and controls show a deficit in an early stage of the decision-making process. Nine patients with ventromedial prefrontal damage, three with dorsolateral prefrontal damage, and eleven healthy controls were tested with a newly developed decision task in which they had to search actively for the information they needed for their decisions. Our results show that patients with ventromedial prefrontal damage compared to the brain-lesioned dorsolateral prefrontal control group and healthy controls searched less for information with regard to risk defusing operators or consequences of their decisions indicating impairment already in the early stage of the decision-making process.

Justification pressure in risky decision making: search for risk defusing operators.

Under justification pressure, the decision maker knows in advance that the decision has to be justified to somebody afterwards. The effect of justification pressure on the search for risk defusing operators (RDOs) and the role of RDOs in the justification texts were investigated. An RDO is an action intended by the decision maker to be performed in addition to an otherwise attractive alternative to decrease the risk. As predicted, in Experiment 1 participants (60 non-students) under justification pressure searched more RDOs. Additionally, in Experiment 2 (80 non-students) RDO search success was varied. Under justification pressure, persistence of RDO search was higher when no RDO could be detected. In the justification texts, the existence or non-existence of RDOs played a prominent role. Searching for RDOs supports people in their goal to make a good decision and in their attempt to convince the addressee of their justification that the decision was good.

Gambles vs. quasi-realistic scenarios: expectations to find probability and risk-defusing information.

The paper investigates predecisional information search in risky decisions, specifically information concerning the probability of a negative outcome and whether a risk-defusing operator (RDO) is available. Experiment 1 (54 participants) tested the hypothesis that search for such information is triggered by expectations that it can be obtained in the situation. Cues for the availability of information were manipulated. It was predicted that cues mentioning possible information sources raise expectations and consequently increase search activity. Furthermore, gambles were expected to differ from other real world contexts, with lower expectations for RDOs and higher ones for probabilities. The Method of Active Information Search was employed. The number of questions asked about probability and RDOs in different conditions confirmed the hypotheses. Experiment 2 (36 participants) ruled out the alternative interpretation that the expectation to actually find favorable probabilities or applicable RDOs respectively, rather than the expectation to obtain information, determined information search.

Detectability of the negative event: effect on the acceptance of pre- or post-event risk-defusing actions.

In risky decision situations, many decision makers search for risk-defusing operators (RDOs). An RDO is an action intended by the decision maker to be performed additionally to a specific alternative and is expected to decrease the risk. Pre-event RDOs (e.g., vaccination) have to be applied before a negative event (e.g., infection) occurs. Post-event RDOs do not need to be initiated before and unless the event happens (e.g., medical treatment). For the successful application of Post-event RDOs, the negative event must be detected in time. Two experiments investigated the effect of uncertainty in the detection of the negative event. In Experiment 1, only a small minority of subjects noted this uncertainty without a cue, and even with cue, only a minority actively searched for probability information. In Experiment 2, the probability for correctly detecting the negative event was varied. When detection was certain, most subjects chose the alternative with a Post-event RDO, whereas this percentage decreased significantly with decreasing probability of correct detection. Also, in the conditions with a more extreme negative outcome, less decision makers chose the alternative with the Post-event RDO.