DYNAMIC IMAGING OF THE WORKING HUMAN BRAIN

Selma Supek, Ph.D.

Magnetoencephalography (MEG) measures weak magnetic fields generated by neuronal activity and allows for a detailed monitoring and tracking of streams of processing in the human cortex. By using spatio-temporal analysis tools and anatomical magnetic resonance imaging (MRI), the underlying neuronal substrates can be identified. However, how many distinct cortical regions can be separated from the data represents a challenging problem not only for MEG but also for all other noninvasive functional brain imaging methods. Neuromagnetic studies examining visual processing, visual and auditory selective attention, imagery mental activity, music and language processing, as well as clinical applications are reviewed to demonstrate the ability of neuromagnetic techniques to provide the neuronal basis and detailed dynamics of sensory and cognitive brain processes in health and disease. Widely available whole-head neuromagnetometers and recently developed specific magnetometers for fetal MEG as well as novel analysis tools are likely to make the use of neuromagnetic techniques more widespread. The unique insight into the dynamics and the interconnectivity of brain regions provided by MEG makes it increasingly important in multi-modality integrations particularly with functional magnetic resonance imaging (fMRI) methods.