The memory hormone?
It’s the hormone that makes people bond with their mates and helps mothers fall in love with their babies. Now researchers have shown that oxytocin plays an essential role in forming social memories.
A dose of oxytocin, administered by nasal spray, made Swiss men much more likely to recognize faces they had seen briefly the day before. But the hormone made no difference when it came to recalling pictures of houses, landscapes or sculptures, according to a study published today in the Journal of Neuroscience.
Scientists from the University of Zurich recruited 41 volunteers and administered three puffs per nostril of either oxytocin or a placebo. After giving the hormone time to reach the brain, volunteers watched 84 black-and-white photographs of faces and 84 images of inanimate objects flash onto a computer screen for 3.5 seconds each.
One day later, the researchers gave a pop quiz: Volunteers were shown the same pictures mixed in with additional images and were asked to identify which were new and which they had seen before.
When it came to recognizing familiar faces, oxytocin made a big difference. The 22 men who inhaled the hormone had an overall "recognition memory rate" of 46% for faces, said psychologist Peter Klaver of University Children’s Hospital Zurich, the study’s senior author. That compared to only 36% for the 19 men who got the placebo. But both groups scored an identical 44% for pictures of houses, landscapes and sculptures, according to the study.
The results suggest oxytocin’s memory-boosting ability works mainly in social situations, the researchers said. That fits well with recent studies showing oxytocin affects other types of human social behavior, such as judgments about whether another person is trustworthy, Klaver said.
-- Karen Kaplan