Targeting central thalamus with transcranial ultrasound reduces arousal in healthy volunteers.

Low-intensity focused transcranial ultrasound targeted to the central thalamus in 27 healthy volunteers increases lapses and slows responses on the Psychomotor Vigilance Task.

• Why it matters: The study addresses how the central thalamus contributes causally to arousal and how the pulvinar contributes to visuospatial attention in the healthy human brain.
• What they did: In a within-subjects, counterbalanced design, participants completed vigilance and Egly-Driver attention tasks before and after sham, central thalamic, or pulvinar sonication.
• The result: Central thalamic sonication reduces arousal, while pulvinar sonication reduces and slows contralateral visual responses, providing causal evidence for region-specific behavioral effects and noninvasive brain mapping.