[Brainmap]: Aapo Numenma PhD-Towards integrated multichannel arrays for transcranial magnetic stimulation and concurrent brain imaging

Wednesday, June 21, 2017 - 12:00 to 13:00
Building 149 Rm 2204



Transcranial Magnetic Stimulation (TMS) has established its role as one of the most widely used neuromodulation techniques due to its capability to deliver supra-threshold stimulation intensities painlessly. During the past two decades, functional Magnetic Resonance Imaging (fMRI) has become ubiquitous in studies of the human brain function.  Electromagnetic brain mapping methods including magneto- and electroencephalography (MEG/EEG) have been further developed to characterize the spatiotemporal dynamics of brain activations with millisecond resolution.  All of these techniques have gained popularity due to their safe and noninvasive nature in addition to their wide availability. TMS has been applied alone and in conjunction with neuroimaging methods (e.g., fMRI and EEG) to dissect the roles of specific brain regions in a variety of motor, perceptive, and cognitive processes. Most TMS applications so far have utilized single coils stimulating one cortical target at a time, with a smaller number of studies using dual coil setups. However, using a large-scale array of TMS coils would enable general-purpose stimulation of multiple targets simultaneously or in rapid succession purely under electronic control. Furthermore, the multichannel TMS targeting approach becomes especially powerful when combined with concurrent neuroimaging capabilities to probe the network dynamics of the TMS induced activations. The MGH Martinos Center TMS Laboratory is currently working on the development of two such integrated multichannel stimulation/imaging systems funded by the NIH – TMSMEG and TMSMRI. In this talk, we will first present the theoretical background for the multichannel TMS targeting and discuss the system design and construction principles. We will then present rationale and overall motivation behind the TMSMRI and TMSMEG projects and show preliminary data and electromagnetic simulations of expected system performance. We will conclude with our future vision on how this kind of integrated neuromodulation and imaging devices may become transformative for clinical non-invasive brain stimulation applications including TMS treatment of depression as well as for cognitive neuroscience applications.