Sjoerd Meijer


My name is Sjoerd Meijer (PhD student 2020-2024) and I use non-invasive brain stimulation techniques to study the neural mechanisms underlying fear and emotional control in humans.

Focused ultrasound neuromodulation opens up a whole new world for the neuroscientific study of anxiety-related brain circuits. This novel non-invasive brain stimulation technique uses ultrasonic waves, which can travel through the skull and deliver highly focused energy at targets deep inside the human brain. Using this technique, we are now able to non-invasively modulate neural activity with a much stronger spatial focus and depth penetration as compared to any other non-invasive brain stimulation technique. This is an exceptionally important development, because most cognitive disorders (e.g., anxiety and depression) are related to abnormal functioning of deep brain structures. Until recently, however, stimulation of deep brain structures was only feasible in neurological patients who, as part of their treatment, had deep brain electrodes implanted during highly invasive medical procedures. With focused ultrasound neuromodulation, we can investigate the effects of deep brain stimulation in a broad population and overcome many of the existing limitations of (non-)invasive brain stimulation techniques. Cognitive disorders constitute one of the largest global health problems of the 21st century and with non-invasive deep brain stimulation we focus on research that has a large potential for clinical impact.

I aim to use this novel brain stimulation technique to test long-standing hypotheses about the involvement of the bilateral amygdala – also known as the brain’s emotion center – in orchestrating the human fear response. I will use validated behavioral paradigms in combination with psychophysiological (skin conductance response, heart rate, pupil dilation) and neural outcome measures (BOLD response) to capture potential changes related to focused ultrasound neuromodulation of the amygdala. By disrupting the human fear circuit at its core, we gain knowledge that could prove essential for the development of next-generation anxiety disorder treatments.
About me:     
I have a background in Psychology (BSc; Radboud University) and Cognitive Neuroscience (MSc; Donders Institute) and I developed a keen interest in emotion-related brain circuits, non-invasive brain stimulation methods and functional neuroimaging.
Co-promotor: dr. Lennart Verhagen (

Head of the neuromodulation lab at the Donders Centre for Cognition (DCC), Nijmegen.
Contact: s.meijer[at]