Risk Evaluation Signals Code for Economic Risk Preferences

Objective : Our willingness to take risks has a large influence on decisions, such as health choices, financial investments or gambling behavior. It remains unclear, however, how risk preferences are integrated during the different stages of decision making. Here, we investigate how risk preferences are reflected in neural regions known to process risk evaluation in anticipation of risky outcomes.

Methods: We collected functional MR images of 56 subjects during a simple gambling task that involves passive risk anticipation and the corresponding risk prediction error (Preuschoff et al., 2006, 2008). Subjects were grouped into risk averters and risk seekers according to the risk preferences they revealed in a separate lottery task.

Results: During the anticipation of high risk gambles, risk averters show stronger responses in ventral striatum and anterior insula compared to risk seekers. In addition, risk prediction error signals in anterior insula, inferior frontal gyrus and anterior cingulate indicate that risk averters do not dissociate properly between gambles that are more or less risky than expected.

Conclusions: Risk preferences are already reflected in the automatic risk-processing independent of an actual choice. The increased anticipation risk signal implies that risk averters are more sensitive to risk than risk seekers. We suggest that risk averters’ general overestimation of risk may be driven by the altered risk prediction error signal and cause their risk-avoidance behavior. Risk preferences may thus be due to alterations on different steps of risk processing, such as the emotional risk evaluation as well as the cognitive inhibition of risk-taking behavior. This has practical implications: public policies dealing with risky decisions should encompass how the subjective evaluation might bias the actual decision.

Literatur: Preuschoff K, Bossaerts P, Quartz SR (2006) Neural Differentiation of Expected Reward and Risk in Human Subcortical Structures. Neuron 51:381-390. Preuschoff K, Quartz SR, Bossaerts P (2008) Human Insula Activation Reflects Risk Prediction Errors As Well As Risk. J Neurosci 28:2745-2752.