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Precision in Space and Time: Brain State-Dependent Stimulation Using Real-Time EEG and TMS

Principal Investigator:
  • Christoph Zrenner, Centre for Addiction and Mental Health
  • Azrieli Foundation

Project Overview

The goal of this project is to develop new principles to treat brain disease and investigate brain function using non-invasive neurostimulation, without the side-effects of drugs. Neurostimulation is already an established treatment for many neurological and psychiatric disorders, such as major depression disorder, but the effectiveness of the method is unreliable, when using today’s methods. Currently, every person receives the same sequence of stimuli, even though every person’s brain is different, and every brain is different from one moment to the next. Instead, we will use a new method to analyze individual brain activity in real-time and apply the stimuli at precisely the right instant to achieve a desired effect.

In this project, we use “time” as a new dimension to interact with specific brain circuits, using naturally occurring brain oscillations. We achieve this by stimulating then brain at only that moment of the oscillation cycle, during which the brain circuit is already active. This project explores whether a fundamental principle of learning and memory at the scale of individual brain cells and even the synaptic connections between the brain cells can be used to investigate the function of the whole brain and to treat brain disease. We will use a non-invasive method to establish an interaction with the brain in both directions and with a high temporal precision: Information about the activity of the brain will be read using electroencephalography (EEG), the brain will be stimulated using trans-cranial magnetic stimulation (TMS).

The experiment proposed in this study is designed to temporarily strengthen or weaken a brain pathway in healthy participants, depending on the millisecond-precise timing of the same stimuli, using the principle of “spike-timing dependent plasticity”, realized with EEG and TMS. If successful, this has direct implications for both basic research and clinical therapeutic protocols.