A small study has suggested that there is a link between the dopamine neurotransmitter system and the ability to recognize different faces. Their findings suggest some sort of connection exists, though the nature of the relationship is less certain.
The study made use of 10 males and 10 female participants, all between the ages of 22 and 30, who were shown a set of 24 faces and asked to remember them. An fMRI scan was then performed while participants were shown the studied faces again, this time with new ones mixed in. A PET scan was also used to determine dopamine availability.
The fMRI showed the largely-expected levels of activity in the fusiform gyrus, the part of the brain that (among other things) is known to be used in facial recognition. The PET scans, meanwhile, showed a correlation between the amount of dopamine being transmitted and the strength of the neurological response.
Since dopamine is involved in the brain’s reward systems, this interaction is thought to be able to help people to become more responsive to social rewards when interacting with familiar faces.
What This Means
Understanding what these findings mean is tricky, since right now it’s just a relatively consistent finding among a very small group of people within a small age range. It could be that the dopamine rates were connected to something else other than facial recognition, and the correlation is coincidence. It could be that the correlation isn’t coincidental, but the dopamine levels were in reaction to some other variable. More work would need to be done to validate the findings regardless, ideally with a larger sample size.
As an aside, it would be interesting to see what the dopamine-fMRI results would be if the tests were performed on someone with prosopagnosia, an inability to recognize faces.
“BrainHealth Scientists Connect Dopamine, Facial Recognition in Study,” UT Dallas web site, September 30, 2016; http://www.utdallas.edu/news/2016/9/30-32211_BrainHealth-Scientists-Connect-Dopamine-Facial-Rec_story-wide.html?WT.mc_id=NewsHomePageCenterColumn, last accessed October 3, 2016.
Rypma, B., et. al., “Dopamine D1 Binding Potential Predicts Fusiform BOLD Activity during Face-Recognition Performance,” Journal of Neuroscience, 2016; 10.1523/JNEUROSCI.1298-15.2015.