Ian is wrapping up a study that explores individual differences in the amount of neurotransmitters in the cortex of the brain and how differences in the amounts of these molecules relate to the excitability of the motor system. The primary goal of this research is to better understand if different amounts of molecules in particular brain areas predict how excitable motor pathways are across individuals. Another objective of this work is to test the reliability of the two different measurement methods we use. The first method, magnetic resonance spectroscopy (MRS), is used to estimate concentrations of metabolites in the brain. The second method, transcranial magnetic stimulation (TMS), can be used to measure excitability in the pathway between the motor cortex and muscles in the body.
Ian is also conducting other projects using MRS and TMS to investigate the role of inhibition in the motor system and how this inhibition relates to behavioral control.
Nicki is currently working on several projects to characterize the brain activity during movements. She is interested in studying both how movement is controlled in the healthy brain. For this research she uses non-invasive methods of brain recordings from electrodes placed on the surface of the scalp (electroencephalography, EEG). She is also interested in how brain activity may differ when movements are abnormal – such as in movement disorders (like Parkinson’s Disease). For this research, in addition to EEG, she records brain signals from the cortex (outer part of the brain) using a technique called electrocorticography (ECoG) and the basal ganglia (deep portions of the brain) using local field potentials (LFPs). For these invasive recordings, the patients are receiving a treatment for their disease called Deep Brain Stimulation (DBS), which involves placing electrodes in the brain during a brain surgery.
The goal of all this work is to better understand how the motor system works and how it might go awry in disease. In addition to shedding light on how the healthy brain works, we hope this could also improve treatments for disease. For instance, if we understand more about the brain activity when Parkinson’s Disease patients are having symptoms, we might be able to use their own brain activity to customize how their DBS device works. This is called ‘closed loop DBS’.