A distributed brain system for decision-making

Recent research on brain mechanisms in decision making is reviewed from studies using the Iowa Gambling Task and similar ones with patients suffering from brain lesions and in normal controls with functional neuroimaging. These studies show that the ventromedial prefrontal cortex and its orbital sector, especially in the right hemisphere play a crucial role in decision-making. However, lesions of the dorsolateral prefrontal cortex and other brain regions will also interfere with the task. Thus, other structures which perform an important role are the anterior cingulate cortex, which is related to anticipation and behaviour choice, the insular cortex, associated to assigning affective values to somatic signals which are a part of anticipation of the affective consequences of decisions, the amygdala, which intervenes in an alert system in response to significant stimuli, particularly those with a negative affective load, and the ventral striatum, when a reinforcing stimulus is expected. We can, therefore, talk about a distributed brain system which intervenes dynamically in decision-making processes.