Oxytocin enhances the encoding of positive social memories in humans.
BACKGROUND
In nonhuman mammals, oxytocin has a critical role in social recognition and the development of long-term bonds. There has been limited research evaluating effects of oxytocin on the encoding and recognition of faces in humans.


METHODS
In a double-blind, randomized, placebo-controlled, between-subject design, we administered oxytocin (24 IU) or a placebo to 69 healthy human male volunteers and then presented 36 happy, angry, or neutral human faces. Participants returned the following day to make "remember," "know," or "new" judgments for a mix of 72 new and previously seen faces.


RESULTS
Oxytocin-administered participants were more likely to make remember and know judgments for previously seen happy faces compared with angry and neutral human faces. In contrast, oxytocin did not influence judgments for faces that had not been presented previously.


CONCLUSIONS
This study shows that the administration of oxytocin to male humans enhances the encoding of positive social information to make it more memorable. Results suggest that oxytocin could enhance social approach, intimacy, and bonding in male humans by strengthening encoding to make the recall of positive social information more likely.
Guastella
Adam J
AJ
Brain & Mind Research Institute, University of New South Wales, Sydney, Australia. aguastella@med.usyd.edu.au
Mitchell
Philip B
PB
Mathews
Frosso
F
D000293:Adolescent; D000328:Adult; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D009483:Neuropsychological Tests; D010120:Oxytocics / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology*; D010364:Pattern Recognition, Visual / Q000187:drug effects*; D010775:Photic Stimulation; D012919:Social Behavior
D010120:Oxytocics; D010121:Oxytocin