Abstract

Research suggests that the nonapeptide oxytocin plays an important role in social functioning, and that the intranasal administration of exogenous oxytocin promotes prosocial behaviours. The mechanisms underlying oxytocin’s effects on social cognition and behaviour are not yet well understood. One viable hypothesis is that oxytocin acts upon frontal asymmetry. Relative left frontal neural activation has been consistently associated with approach behaviours and shares a number of other similarities with intranasal oxytocin administration. For the first time, we examined the hypothesis that oxytocin increases relative left frontal neural activation using electroencephalography methodology. In a double-blind within-subject experiment, 48 participants self-administered a 24 I.U. dose of intranasal oxytocin and placebo approximately one week apart. Following drug administration, alpha band power was recorded at frontal and parietal sites during eight 60 second trials. Intranasal oxytocin administration did not produce any significant changes in frontal asymmetry (F(1, 47) = .273, p= .604, partial η2 = .006). This relation did not interact with sex nor measures of depression, which have been shown to moderate the effects of intranasal oxytocin in prior investigations. Oxytocin administration does not appear to increase relative left frontal neural activation. Additional considerations and interpretations are discussed.