Dynamic Changes in Human Brain Connectivity Following Ultrasound Neuromodulation

Non-invasive neuromodulation represents a major opportunity for brain and mental health interventions. Based on its ability to target deep-brain structures, transcranial focused ultrasound neuromodulation is the most promising approach, destined to change clinical practice. However, some challenges prevent the community from fully understanding its outcomes and therefore moving to the next research step. Here we addressed one of them and unravelled the temporal dynamics of the ultrasound neuromodulation effects in humans. Our findings reveal that the effects of ultrasound neuromodulation are predominantly time-constrained and spatially distributed in brain regions functionally connected with the directly stimulated area. Furthermore, these biological effects are indicative of behavioural changes that persist for at least an hour following stimulation. Our study provides a detailed understanding of how ultrasound stimulation alters brain function over time. This is a first step towards the future prediction of the dynamic effects of ultrasound neuromodulation in terms of brain activity and behaviour, including both immediate (recorded during the stimulation) and long-term consequences (hours or days after the stimulation) of ultrasound neuromodulation.