Figure - available from: Journal of Risk and Uncertainty
This content is subject to copyright. Terms and conditions apply.
Preference Changes (S) during IA common ratio tests. (A) Significant positive Preference Change measure S (all P < 0.05; one-sample t-test). For conventions, see Fig. 2. (B) Significant negative Preference Changes S. (C) Insignificant Preference Changes S

Preference Changes (S) during IA common ratio tests. (A) Significant positive Preference Change measure S (all P < 0.05; one-sample t-test). For conventions, see Fig. 2. (B) Significant negative Preference Changes S. (C) Insignificant Preference Changes S

Source publication
Article
Full-text available
Unlabelled: Expected Utility Theory (EUT) provides axioms for maximizing utility in risky choice. The Independence Axiom (IA) is its most demanding axiom: preferences between two options should not change when altering both options equally by mixing them with a common gamble. We tested common consequence (CC) and common ratio (CR) violations of th...

Citations

Article
In a model inspired by neuroscience, we study choice between lotteries as a process of encoding and decoding noisy perceptual signals. The implications of this process for behavior depend on the decision-maker’s understanding of risk. When the aggregation of perceptual signals is coarse, encoding and decoding generate behavioral risk attitudes even for vanishing perceptual noise. We show that the optimal encoding of lottery rewards is S-shaped and that low-probability events are optimally oversampled. Taken together, the model can explain adaptive risk attitudes and probability weighting, as in prospect theory. Furthermore, it predicts that risk attitudes are influenced by the anticipation of risk, time pressure, experience, salience, and availability heuristics.
Article
Behavior-related neuronal signals often vary between neurons, which might reflect the unreliability of individual neurons or a truly heterogeneous code. This notion may also apply to economic ("value-based") choices and the underlying reward signals. Reward value is subjective and can be described by a nonlinearly weighted magnitude (utility) and probability. Defining subjective values relies on the continuity axiom, whose testing involves structured variations of a wide range of reward magnitudes and probabilities. Axiom compliance demonstrates understanding of the stimuli and the meaningful character of choices. Using these tests, we investigated the encoding of subjective economic value by neurons in a key economic-decision structure of the monkey brain, the orbitofrontal cortex (OFC). We found that individual neurons carry heterogeneous neuronal value signals that largely fail to match the animal's choices. However, neuronal population signals matched the animal's choices well, suggesting accurate subjective economic value encoding by a heterogeneous population of unreliable neurons.
Preprint
Full-text available
The past decades have seen tremendous progress in fundamental studies on economic choice in humans. However, elucidation of the underlying neuronal processes requires invasive neurophysiological studies that are met with difficulties in humans. Monkeys as evolutionary closest relatives offer a solution. The animals display sophisticated and well-controllable behavior that allows to implement key constructs of proven economic choice theories. However, the similarity of economic choice between the two species has never been systematically investigated. We investigated compliance with the independence axiom (IA) of expected utility theory as one of the most demanding choice tests and compared IA violations between humans and monkeys. Using generalized linear modeling and cumulative prospect theory (CPT), we found that humans and monkeys made comparable risky choices, although their subjective values (utilities) differed. These results suggest similar fundamental choice mechanism across these primate species and encourage to study their underlying neurophysiological mechanisms.