among people with disorders such as Parkinson’s disease or
schizophrenia may be affected by changes in the levels dopamine in the
is a chemical messenger – often known as the ‘happy hormone’ – that
carries signals controlling mental and emotional responses in the brain.
Parkinson’s disease and other neurological disorders are known for
their links with low or disrupted dopamine levels that cause those
affected to struggle with a number of social skills. This is the first
time, however, that a positive connection has been made between dopamine
and the ability to recognise emotions in others.
The ability to recognise emotions in others is fundamental to our everyday social interactions and this is often atypical in people with neurological disorders. Our research shows that dopamine medication – even in small doses – can affect these abilities.Dr Bianca Schuster, Centre for Human Brain Health
In a new study, published in the Journal of Neuroscience,
researchers in the University of Birmingham's Centre for Human Brain
Health showed that manipulating levels of dopamine affected emotion
recognition. More specifically, the research showed that while people
with low baseline levels of the chemical messenger became better at
emotion recognition after receiving a dopamine boost, those with higher
baseline levels actually became worse.
Lead author Dr Bianca Schuster said: “The ability to recognise
emotions in others is fundamental to our everyday social interactions
and this is often atypical in people with neurological disorders. Our
research shows that dopamine medication – even in small doses – can
affect these abilities. That has important implications for fine-tuning a
patient’s medicine regime to ensure a balance between controlling their
symptoms and preserving social functions.”
In the study, the team worked with 33 healthy male and female
individuals and assessed their baseline dopamine levels. This was done
by testing people’s working memory, a well-recognised proxy for dopamine
levels that avoids invasive brain imaging.
Individuals were asked to gauge the emotions of a series of figures
in three different video clips in two separate tests. In the first, they
were given a dose of haloperidol, a drug affecting brain dopamine
levels which is commonly used to treat schizophrenia, and in the second
they were given a placebo. The figures were seen walking, in outline
only, and in three different gaits and postures, denoting angry, happy
and sad emotions.
Participants with a lower working memory, and so assumed lower
baseline levels of dopamine, improved their emotion recognition under
haloperidol, whereas those with a higher working memory became worse at
emotion recognition under the drug.
“Individuals with low baseline dopamine also slowed their own walking
pace under haloperidol, and so we think the effects of the drug on
movement and emotion recognition are connected,” says Dr Schuster. “It
is not yet clear, however, why the drug actually impaired emotion
recognition in the participants with high baseline dopamine. It’s likely
that timing and movement are not the only mechanisms that are
More work needs to be done to confirm whether these results predict the effects of dopamine in other emotion recognition tasks.