We study how chemicals in our brain help us motivate ourselves to obtain our goals, in other words, to have willpower. 

Imagine yourself in front of a lovely glass of wine. Now imagine that, just at the moment of your first sip, you receive a phone call from your kids' school telling you that your kid needs to be picked up immediately. You can only get there by car. We study how our brain helps us resist the urge to drink from the glass of wine, in other words to exert willpower, to obtain your ultimate goal of getting your kid home safely. 

Our work is important for people who have problems with willpower, such as those with attention deficit hyperactivity disorder, addiction or eating disorder.

How do we aim to do that? 
Our overarching goal is to understand the neural and neurochemical mechanisms underlying flexible behaviour, which requires motivational and cognitive control as well as reinforcement learning. We aim to characterize: (i) the distinct contribution of the basal ganglia from that of the prefrontal cortex; (ii) the role of neuromodulators, in particular dopamine and serotonin and (iii) individual differences at the level of personality traits, baseline neurotransmitter levels and genotypic variation. To this end, we combine cognitive psychology with psychopharmacology, functional neuroimaging and patient studies (e.g. Parkinson’s disease & ADHD).

Examples of specific questions include:

Why do the same dopaminergic drugs improve flexible behaviour in some individuals, while impairing it in others?
Drugs act on systems with optimal levels of neurotransmitter activity, where too much as well as too little activity impairs behavior. Our recent findings demonstrate that the large variability in dopaminergic drug effects on reinforcement learning and flexible behaviour across different individuals reflects quantitative variation in baseline striatal dopamine function. Next steps include assessing whether this variability in drug effects reflects individual differences in structural and functional fronto-striatal connectivity as a function of genetic variation in dopamine genes.

How is the role of the striatum different from that of the prefrontal cortex?
Abundant evidence indicates a key role not only for the striatum, but also for the PFC in the cognitive control of flexible behaviour. We aim to assess the necessary and unique contribution of dopamine in the prefrontal cortex and dopamine in the striatum to cognitive control.

How does the striatum interact with the PFC to bias cognitive flexibility?
How does the brain know whether or when to be flexible? The striatum does not act alone, but interacts with the prefrontal cortex to bias flexibility. A third aim is to assess whether the prefrontal cortex is critical for controlling flexibility by exerting top-down control over striatal dopamine.

Other topics of interest include receptor-specificity of dopaminergic drug effects on behaviour and the distinct behavioural roles of dopamine and serotonin in reinforcement learning.