How can you tell if a decision was impulsive or risky? Using the Cambridge Gambling Task to unpick how different brain regions, different drugs and different dopamine levels impact on decision-making.
The Cambridge Gambling Task (CGT) was designed to measure decision-making under risk. The term decision-making under risk refers to when the outcome of a decision is unknown, but the probability of such an outcome is known (Camerer & Weber, 1992).
The odds of winning or losing are made explicit in the CGT by the ratio of red to blue boxes. The task requires participants to decide whether a token will be hidden behind a red box or a blue box. Participants are then asked to bet a proportion of their points to support this decision.
The CGT separates itself from more traditional gambling tasks with the crucial ability to dissociate risk-taking from impulsivity. This is due to the different bet conditions of the task. In the ascending condition, the bet value incrementally increases on screen so the participant is required to wait (not be impulsive) in order to place a high-stakes bet (take a risk).
Furthermore, the task places limited demands on learning and working memory, as information from one trial does not inform the next. Consequently, the CGT is a clean measure of decision-making under risk, and therefore a good paradigm to explore the neuroscience behind such decision-making. Here we will discuss some key research into this area that has used CGT.