This study examines the effects of a medication called ropinirole in healthy volunteers rather than in people with a specific disease. The research focuses on understanding how this drug affects a person’s ability to judge their own thinking and performance, which is called metacognition. Metacognition means being aware of how well one is doing on mental tasks and being able to accurately assess one’s own abilities. The study will compare the effects of ropinirole with placebo to see if the medication changes how confident people feel about their answers and how well their confidence matches their actual performance. The medication works by affecting a brain chemical called dopamine, and researchers want to know if changing dopamine levels makes people more overconfident or less able to tell when they have made mistakes.

The purpose of this study is to determine whether a single dose of ropinirole changes metacognitive performance in healthy adults and to understand how brain chemistry affects self-awareness and the ability to monitor one’s own thinking. Participants will receive either ropinirole or placebo on different occasions, and they will complete cognitive tasks that test memory and thinking while rating how confident they are in their answers. The study will measure whether the medication makes people feel more or less confident compared to their actual performance and whether it affects their ability to distinguish correct answers from incorrect ones.

During the study, participants will undergo brain imaging using resting-state fMRI, which is a type of scan that shows how different parts of the brain communicate with each other when a person is not performing any specific task. The researchers will look at specific brain networks including the Default Mode Network and Salience Network to see if ropinirole changes the connections between brain regions. Each participant will take part in sessions where they receive either the medication or placebo, complete cognitive tests with confidence ratings, and have brain scans to examine how the drug affects both brain activity and the ability to judge one’s own performance.