Effect of distracting faces on visual selective attention in the monkey

Area of Science:

• Neuroscience
• Cognitive Science
• Primate Behavior

Background:

• Visual stimuli with social and emotional content capture attention in primates.
• Attention can be processed via rapid subcortical or slower cortical pathways.

Purpose of the Study:

• To investigate if irrelevant emotional faces interfere with a covert attention task in macaque monkeys.
• To determine the temporal dynamics and neural mechanisms underlying attentional capture by emotional faces.

Main Methods:

• Macaque monkeys performed a peripheral covert attention task while ignoring facial distracters.
• Distracter face onset time and spatial proximity to the target were manipulated.
• Interference effects on task performance, saccade velocity, and pupillary reflex were measured.
• The effect of intranasal oxytocin on face-induced interference was assessed.

Main Results:

• Irrelevant faces, particularly emotional ones, interfered with the attention task, indicating competition for resources.
• Significant interference occurred only when faces were presented for over 200 ms.
• Emotional faces altered saccade velocity and reduced pupillary reflex.
• Intranasal oxytocin administration ameliorated the interference caused by faces.

Conclusions:

• Attraction of attention by emotional faces in primates is a relatively slow process, likely involving cortical-subcortical interactions.
• Emotional distracters modulate attention through a time-dependent mechanism.
• Oxytocin plays a role in modulating attention to social stimuli, possibly via oxytocinergic pathways.