Enhancing the effects of the brain chemical dopamine influences how people make life choices by affecting expectations of pleasure.

The study, published in Current Biology, confirms an important role for dopamine in how human expectations are formed and how people make complex decisions.

Dopamine is a neurotransmitter produced in several areas of the brain that is found in a wide variety of animals. Its role in reward learning and reward-seeking behaviour is well established by animal studies - however, in humans its role is much less understood.

Lead author Dr Tali Sharot, Wellcome Trust Centre for Neuroimaging at UCL, said: "Humans make much more complex decisions than other animals - such as which job to take, where to go on holiday, whether to start a family - and we wanted to understand the role of dopamine in making these types of decisions.

Our results indicate that when we consider alternative options when making real-life decisions, dopamine has a role in signalling the expected pleasure from those possible future events. We then use that signal to make our choices."

The research team, which included Dr Tamara Shiner and Professor Ray Dolan, examined estimated pleasure of future events before and after the administration of a drug called L-DOPA which is known to enhance dopamine function in the brain and is commonly used to treat patients with Parkinson's disease.

The 61 study participants were asked to rate their expectations of happiness if they were to holiday at each of 80 destinations, from Thailand to Greece. They were then given L-DOPA or a placebo and asked to imagine holidaying in those destinations.

Source: University College London