Chronic oxytocin administration in older men modulates functional connectivity during animacy perception

Area of Science:

• Neuroscience
• Social Neuroscience
• Gerontology

Background:

• Aging is linked to social-cognitive changes, with oxytocin crucial for social cognition.
• Oxytocin's impact on the aging social brain, particularly animacy perception mechanisms, is understudied.
• No prior research investigated chronic intranasal oxytocin effects on brain activity during animacy perception in older adults.

Purpose of the Study:

• To investigate the effects of four-week intranasal oxytocin on brain mechanisms of animacy perception in older men.
• To examine functional magnetic resonance imaging (fMRI) changes during the Heider-Simmel task after oxytocin or placebo intervention.
• To determine if oxytocin influences functional connectivity (FC) within social perception networks.

Main Methods:

• A placebo-controlled, randomized, double-blind study with healthy older men (mean age 69).
• Participants received either intranasal oxytocin (24 IU twice daily) or placebo for four weeks.
• fMRI was used during the Heider-Simmel task, comparing social (SOCIAL) vs. random (RANDOM) conditions.

Main Results:

• No significant oxytocin-specific effects on direct brain activation between SOCIAL and RANDOM conditions.
• A greater increase in the SOCIAL-RANDOM difference in functional connectivity (FC) was observed in the oxytocin group compared to placebo.
• This FC change occurred in a network including occipital, temporal, parietal areas, and the superior temporal sulcus.

Conclusions:

• Chronic intranasal oxytocin can modulate brain circuits involved in action observation and social perception in older adults.
• Oxytocin may counteract habituation effects seen in placebo groups during social perception tasks.
• Findings advance understanding of oxytocin's mechanisms within the aging social brain.