From circuit mechanisms to adaptive intervention.
Our projects combine mechanistic neuroscience, multimodal measurement and non-invasive stimulation. Across movement, cognition and methodology, the aim is the same: understand the relevant circuit well enough to intervene more precisely.
ADAPT-PD: Adaptive Non-Invasive Closed-Loop Neuromodulation for Parkinson’s Disease
Parkinson’s disease is a progressive neurological disorder that gradually impairs movement, flexibility and daily functioning. In the Netherlands, around 67,000 people live with Parkinson’s disease or parkinsonism, and recent population-based estimates indicate roughly 3,700 new diagnoses each year.
Slowness, stiffness, freezing and difficulty initiating or adapting movements can make everyday actions unpredictable and effortful. Medication and deep brain stimulation can be highly effective, but benefit can fluctuate across the day and some patients experience insufficient symptom relief or side effects.
Motor symptoms in Parkinson’s disease are closely associated with excessive beta synchronization in cortico-basal ganglia motor circuits. ADAPT-PD develops a personalized, non-invasive strategy designed to reduce this pathological synchrony using closed-loop transcranial alternating current stimulation (tACS). Ongoing brain activity is monitored in real time so that stimulation can be aligned to the patient’s current neural state and delivered when excessive beta activity is present.
The mechanistic rationale is phase-specific opposed-wave stimulation. When stimulation is delivered in opposition to the ongoing rhythm, it can reduce oscillatory synchronization through destructive interference. Our work in healthy participants shows that phase-specific tACS can alter beta activity and motor behaviour, while our ongoing work investigates how cortical stimulation engages deeper motor circuitry.
The central question is whether this approach can reliably suppress pathological beta activity in Parkinson’s disease and whether that neural effect translates into meaningful improvements in movement. We will first compare stimulation strategies to identify the most effective and patient-feasible approach, then evaluate the best-performing strategy in a sham-controlled clinical study. Outcomes will include beta activity in motor circuits as well as movement speed, rigidity, and the ability to initiate and adapt movements.
The long-term aim is a patient-centred, non-invasive treatment that complements existing therapies by responding to the brain state that is present at that moment, rather than stimulating in the same way continuously.
T4TE: TMS-Evoked Potentials and their Link to Alpha Oscillations
How much do methodological choices change what we conclude from TMS–EEG experiments?
Cross-laboratory variability in acquisition and analysis can influence neurophysiological results, making it difficult to know whether differences between studies reflect biology or methodology. This project addresses that problem directly through the international Team for TMS–EEG (T4TE) initiative.
Twenty laboratories will collect TMS–EEG data using a common experimental protocol while retaining their own acquisition procedures, and 21 EEG analysts will independently process the data using their own analysis pipelines. This design allows methodological variability itself to become the object of study rather than an uncontrolled source of noise.
Using Bayesian hierarchical models, the project will quantify how acquisition and analysis decisions influence canonical TMS-evoked potentials (TEPs) and inferences about state dependence, focusing on whether prestimulus alpha oscillations shape the cortical response to TMS.
The goal is to establish practical benchmarks for interpreting TMS–EEG findings across laboratories, improve reproducibility, and help separate robust neurophysiological effects from pipeline-dependent conclusions.
Advanced Neural Control to Restore Brain Function
A joint Maastricht–Radboud programme is building the scientific and technological foundation for a regional Neurocontrol Center focused on non-invasive, personalized brain stimulation.
Within this collaboration, our lab contributes to bringing transcranial focused ultrasound expertise into Maastricht. Ultrasound is particularly exciting because it offers a route to modulate targets that are deeper and more spatially focal than those typically reached with conventional non-invasive electrical or magnetic stimulation.
The programme connects Maastricht strengths in cognitive neuroscience, brain stimulation and high-field imaging with Radboud expertise in neurotechnology, AI and focused ultrasound. For our lab, this creates a platform to test whether mechanistically defined deeper circuits can be engaged non-invasively and to compare ultrasound with other stimulation approaches such as tACS.
The broader collaboration also supports shared training, student exchange, joint methods development and new translational projects across Maastricht and Nijmegen. In practical terms, it gives us the opportunity to develop the infrastructure, expertise and collaborations needed to make ultrasound a sustained part of the Maastricht neuromodulation toolbox.