According to a new study published in the first journal of society for neuroscience, jneurosci, the neurotransmitter dopamine, known for its role in reward, is also involved in emotion recognition** People with dopamine disorders, such as Parkinson's disease or schizophrenia, often have social cognitive difficulties.
However, the link between dopamine and specific social behaviors remains elusive, in part because of inconsistent results that do not take into account individual differences in dopamine levels.
In the study, healthy participants took haloperidol, a dopamine receptor inhibitor, one day and placebo the other day before completing the emotion recognition task. They assessed videos of people expressing certain emotions based on their posture and gait (i.e. slow when sad, fast and stiff when angry). The researchers also indirectly measured baseline dopamine levels by testing each person's working memory.
The effect of haloperidol was different according to each person's baseline dopamine level. In people with low levels of dopamine, the drug improved their ability to recognize emotions, while in people with high levels of dopamine, the drug impaired their ability. Next, the researchers will study how changes in dopamine levels in diseases such as Parkinson's disease lead to impairment of social cognition.