Oral, similar to intranasal, administration of oxytocin decreases top-down social attention, but additionally enhances bottom-up control

The neuropeptide oxytocin (OXT) can modulate social cognition by facilitating attention towards social cues and may be a potential therapeutic intervention for social attention impairment in disorders such as autism. Intranasal administration of OXT is widely used to examine its functional effects in both adults and children. However, we have recently shown that administration orally as a lingual spray also modulates neural responses to emotional faces and is potentially better tolerated for therapeutic use. Here, we therefore examined if 24IU OXT administered orally is also effective in facilitating social attention. In a randomized, placebo-controlled, pharmacological study we used a validated emotional anti-saccade eye-tracking paradigm to explore effects of oral OXT on bottom-up and top-down attention processing in 80 healthy male subjects. Our findings showed in terms of top-down attention, oral OXT increased both errors and response latencies for all social stimuli (angry, fearful, happy, sad and neutral emotion faces) but not non-social stimuli (oval shape) in the anti-saccade condition. Comparison with our previous intranasal OXT study using the same task paradigm revealed both routes have a similar effect on increasing anti-saccade errors. However, compared with intranasal OXT, oral OXT significantly decreased error rates for social stimuli in the pro-saccade condition, indicative of increased bottom-up attention processing. Additionally, OXT administration both either route produced an anxiolytic effect evidenced by reduced state anxiety scores. Together, these findings suggest that orally administered OXT has a similar effect on top-down social attention control and anxiety as intranasal administration but more potently influences bottom-up control.