Low-intensity focused ultrasound modulates monkey visuomotor behavior

Area of Science:

• Neuroscience
• Cognitive Science
• Biomedical Engineering

Background:

• Low-intensity focused ultrasound (FUS) has shown potential for noninvasive brain modulation in anesthetized animals.
• FUS offers advantages over existing methods, including no need for surgery or genetic modification and potentially superior spatial resolution.

Purpose of the Study:

• To assess the feasibility of using noninvasive FUS to causally modulate high-level cognitive behavior in awake nonhuman primates.
• To investigate the effects of FUS on prefrontal activity during a cognitive task.

Main Methods:

• Two awake macaque rhesus monkeys were trained on an antisaccade (AS) task.
• Noninvasive FUS was applied to modulate prefrontal activity during the AS task.
• Changes in AS latencies were measured to assess behavioral modulation.

Main Results:

• Focused ultrasound significantly modulated antisaccade (AS) task latencies.
• The observed effects were dependent on the FUS stimulation hemifield, with ipsilateral stimulation causing the most significant latency increases.
• Results suggest FUS disrupted processing in the frontal eye fields, modulating saccade inhibition.

Conclusions:

• This study demonstrates the first successful causal modulation of behavior in the awake nonhuman primate brain using FUS.
• FUS neurostimulation is a viable noninvasive tool for studying brain function and has potential for exploratory and therapeutic applications.
• The technique offers high spatial resolution for noninvasive brain modulation.