Brain regions modulated during covert visual attention in the macaque

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Primate Neurophysiology

Background:

• Neurophysiological studies in monkeys show attention modulates visual cortex responses.
• Electrophysiological and fMRI studies indicate attention involves widespread brain networks.

Purpose of the Study:

• To identify brain structures involved in the control of covert visual attention using fMRI in monkeys.
• To extend previous findings and create a more comprehensive list of attention-related brain regions.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used in two monkeys performing covert attention tasks.
• A control experiment with a second-order orientation stimulus was conducted to assess motion independence.

Main Results:

• Attention-related modulation was observed in expected areas: frontal, parietal, visual cortex, superior colliculus, and pulvinar.
• Novel attention-related modulation was found in mid-STS areas (anterior FST, IPa, PGa, TPO) and the caudate nucleus.
• Modulation in a subset of mid-STS areas was independent of visual motion.

Conclusions:

• The mid-STS areas (anterior FST, IPa, PGa, TPO) and caudate nucleus are identified as potentially important for covert visual attention control in monkeys.
• These findings expand the known neural circuitry underlying visual attention.