This was, of course, a team effort! A huge thank you to all the collaborators: @ben-kop.bsky.social, @reneecabbage.bsky.social, Solenn Walstra, José Marques, @achetverikov.bsky.social, @pmedendorp.bsky.social, @lennartverhagen.bsky.social, and Hanneke den Ouden 💛

💎 Why is this important? This study provides behavioral and neurophysiological evidence for using TUS to directly influence brain circuits, making it a powerful tool to study temporally dynamic brain-behavior relationships, opening new possibilities for neuroscience and clinical applications! 🔊🧠

💡Key highlights:
- TUS modulates saccadic movements with high spatial and temporal precision
- Inhibitory circuits in the FEF play a key role in decision-making
- GABA+ levels drive variability in how individuals respond to TUS
- TUS offers a tool for probing individual differences in brain function

🔊🧠 By targeting the FEF, a brain circuit with a well-characterized link to measurable behavior, and combining behavioral assays with brain imaging, our study shows how TUS can probe fast neural dynamics AND bridges the gap between animal and human research (inspired by the Kubanek et al 2020 paper!)

🙅🏻‍♀️ To ensure our results weren't skewed by auditory or somatosensory confounds, we stimulated the left and right primary motor cortex (M1) as a control site. We found no significant changes in behavior after M1 stimulation, confirming that our observed effects were specific to FEF TUS. 🙌🏽

😮 The twist? Individual differences matter. 🧍🏿🧍🏼‍♀️🧍🏻‍♂️We show that baseline GABAergic inhibitory tone (measured via MRS) predicts the magnitude of the TUS-induced effects. This highlights how neurophysiological state influences the outcomes of neuromodulation.

🔑 Our key finding: TUS over the FEF excites saccadic behavior, effectively biasing saccades towards the contralateral side. 👀 This confirms that TUS can modulate decision-making circuits in humans in real time. 🔊🧠 More on that soon!

🧠 A challenge in neuroscience: How do we establish causal brain-function relationships with spatial and temporal precision? We already know that TUS can target very focally, but now we show it’s also great for studying fast brain dynamics by developing a protocol to explore these effects. 🚀

👀 Look to your left! Look to your right! I just 'stimulated' your frontal eye fields (FEFs)! 🧠 In our latest study, we developed a temporally precise Transcranial Ultrasonic Stimulation (TUS) protocol to modulate the human FEFs & uncover new insights into brain function!👇

doi.org/10.1101/2025...