Choices, it is commonly understood, lead to action – but how does this happen in the brain? Intuitively, we first make a choice between the options. For example, when approaching a yellow traffic light, we need to decide either to hit the breaks or to accelerate the car. Next, the appropriate motor response is selected and carried out, in this case moving the foot to the left or to the right. Traditionally, it is assumed that separate brain regions are responsible for these stages. Now researchers have found evidence that challenges this intuitive division between a 'deciding' and a 'responding' stage in decision making.

Source: Not really a matter of choice?