Authors:

YU, R., MOBBS, D. & CALDER, A.

Reference:

Year of publication:

2009

CBU number:

7092

Abstract:

Frustration aggression theory states that frustration, elicited by the unfulfilled appetitive motivation to attain a reward or goal, is an antecedent to aggression. It has been hypothesized that the amount of frustration is a function of the strength of the desire to obtain the goal. Previous studies suggest that motivation increases with increasing proximity to the goal — the ‘goal gradience effect’ — and with the amount of prior expenditure in resources or effort, known as the 'sunk cost effect'. Given the hypothesized link between motivation and frustration, we theorized that the closer one is to a goal, and the larger the effort expended on the goal, the stronger the motivation to reach it, and subsequently the stronger the frustration after goal blockage. We designed a functional magnetic resonance imaging (fMRI) experiment to assess how reward proximity and expended effort affect the motivation to obtain the reward and the frustration when the reward is blocked. As hypothesized, the self reported motivation to obtain the reward and the frustration after reward blockage were enhanced with increasing reward proximity and effort. Our preliminary fMRI results show that increasing motivation was associated with the activation in ventral striatum and caudate. As the reward blockage occurred closer to the final goal, brain activity in amygdala increased while activity in vmPFC decreased. Failure to inhibit the aversive emotion induced by unmet desire may underlie the frustration-evoked aggression.