Virginia Tech Carilion Research Institute scientists, led by Professor William Tyler, have demonstrated that ultrasound directed to a specific region of the brain can boost performance in sensory discrimination. This is the first example of low-intensity, transcranial-focused ultrasound modulating human brain activity to enhance perception.
The scientists delivered focused ultrasound to an area of the cerebral cortex that corresponds to processing sensory information received from the hand. To stimulate the median nerve, they placed an electrode on the wrist and recorded brain responses using EEG. Before stimulating the nerve, they began delivering ultrasound to the targeted brain region. The ultrasound decreased the EEG signal and weakened the brain waves responsible for encoding tactile stimulation.
Subjects were then given two neurological tests: the two-point discrimination test, which measures a one’s ability to distinguish whether two nearby objects touching the skin are truly two distinct points, rather than one; and the frequency discrimination task, which measures sensitivity to the frequency of a chain of air puffs. The subjects receiving ultrasound showed significant improvements in their ability to distinguish pins at closer distances and to discriminate small frequency differences between successive air puffs.