Affective bias, the tendency to differentially prioritise the processing of negative relative to positive events, is commonly observed in clinical and non-clinical populations. However, why such biases develop is not known. Using a computational framework, we investigated whether affective biases may reflect individuals' estimates of the information content of negative relative to positive even...

Animals and humans learn to approach and acquire pleasant stimuli and to avoid or defend against aversive ones. However, both pleasant and aversive stimuli can elicit arousal and attention, and their salience or intensity increases when they occur by surprise. Thus, adaptive behavior may require that neural circuits compute both stimulus valence--or value--and intensity. To explore how these co...

The Iowa Gambling Task (IGT) involves probabilistic learning via monetary rewards and punishments, where advantageous task performance requires subjects to forego potential large immediate rewards for small longer-term rewards to avoid larger losses. Pathological gamblers (PG) perform worse on the IGT compared to controls, relating to their persistent preference toward high, immediate, and unce...

Individuals with elevated symptoms of depression exhibit deficits in decision-making. Depressed individuals show decreased sensitivity to rewards, but increased sensitivity to punishments. This may be critical to understanding depressionrelated decision-making deficits, yet the computational nature of these effects is poorly understood. Participants (N=161) completed a decision-making task wher...

Mental Capital and Wellbeing. The views expressed do not represent the policy of any Government or organisation. 2 Summary The onset of substance use coincides with a critical maturation period of the neural substrates that are affected by alcohol and other drugs of abuse. Behaviourally, adolescents exhibit distinct patterns of risk-taking. Moreover, neuroimaging studies have shown that these i...

A recent flurry of neuroimaging and decision-making experiments in humans, when combined with single-unit data from orbitofrontal cortex, suggests major additions to current models of reward processing. We review these data and models and use them to develop a specific computational relationship between the value of a predictor and the future rewards or punishments that it promises. The resulti...

Research has increasingly implicated the striatum in the processing of reward-related information in both animals and humans. However, it is unclear whether human striatal activation is driven solely by the hedonic properties of rewards or whether such activation is reliant on other factors, such as anticipation of upcoming reward or performance of an action to earn a reward. We used event-rela...

Recent work shows that both reward and punishment systems increase short-term cooperation in social dilemmas. Yet, a growing body of research finds that punishment systems generate a range of negative side effects, including an undermining of trust in fellow group members’ cooperative intentions. The present work asks whether reward systems can generate the same positive effects as punishment s...

Positive and negative selective incentives are shown analytically to have different structural implications when used to induce collective action. Positive selective incentives are effective for motivating small numbers of cooperators and generate pressures toward smaller, more "elite" actions, unless the incentives have jointness of supply. Negative selective incentives are effective for motiv...