Nursing faculty need to stay aware of significant changes in our knowledge of human physiology and make current scientific information available to our students. An example of a significant recent discovery involves oxytocin, the posterior pituitary hormone that we have long known stimulates uterine contraction and milk ejection. Psychologist Ulrike Rimmele of the University of Zurich in Switzerland and colleagues have determined that oxytocin helps us determine whether or not a human face is familiar.

The research team gave half of a volunteer group of 44 heterosexual men a nasal spray spiked with oxytocin. The men were asked to view a series of 128 pictures (half of them of people and half of object) for a few seconds. The men then used a Likert scale, ranking from one to ten, to indicate how much they would like to approach each person or object represented by the photographs. The following day, the men were asked to again view the pictures they had viewed the previous day, along with 72 new photos.

The researchers reported that oxytocin influenced whether or not the men recognized previously viewed faces. The men who received the oxytocin nasal spray picked out 46% of the familiar faces, while the control group only recognized 36%. Additionally, the men who received the oxytocin were more accurate in identifying the unfamiliar faces that they had not seen on the previous day.

Thomas Insel, director of the National Institute of Mental Health in Bethesda, has previously shown that oxytocin improves the ability of mice to recognize each other. He adds that the recent Swiss study "...supports the notion that social memory is a unique form of memory, biologically distinct from general object memory."

The co-author of the Swiss study, Markus Heinrichs, already has evidence that treatment with oxytocin is beneficial to people with either social phobias or autism. He and colleagues are further pursing the role of oxytocin in mental disorders that impact social functioning.

So, the next time you give that lecture that mentions oxytocin, add a bit of information about the role of the hormone in social recognition.

Source: Holden, C. January 6, 2009. Haven't I seen you before? ScienceNOW. Available at:http://sciencenow.sciencemag.org/cgi/content/full/2009/106/1?etoc. Accessed on January 21, 2009.