When we are motivated we move faster. We studied the effects of a drug that stimulates receptors for the neurotransmitter dopamine (Au Yeung et al. Psychopharmacology 2024). Dopamine may be important for signalling rewards in the brain.
We gave healthy people a course of the drug Pramipexole. Before and after the course, we tested their movement speed. They moved faster after drug, compared to placebo.
People move faster when they expect a reward. We asked whether reward was more effective on pramipexole. Surprisingly, we did not find an effect, suggesting that the dopamine receptors we were studying are important for speed, but not for reward-related speeding. So dopamine may not be as critical as we thought, for motivation.