Using Magnetic and Electric Fields to Image How Your Brain Functions

Uncovering how the brain functions is what the field of Neuroscience is all about. Looking into the brain, non-invasively by using techniques, based on the principles of physics, such as Magnetoencephalography (MEG), and Electroencephalography (EEG) provide access to the cortical regions and networked pathway used to transmit and receive information throughout the brain. These two techniques are able to detect the electrical activity of the cells in the brain by using sensors placed on and around the scalp. EEG provides frequency information with high temporal resolution (in the millisecond range) while MEG can provide both high temporal and high spatial resolution (in the millimeter range). MEG and EEG are used clinically to investigate abnormal brain activity in patients with epilepsy. These techniques are complementary and when used simultaneously provide unique information. MEG is best suited to detect tangential components while EEG is best suited to detect radial components of the underlying neuronal currents. Epileptic Seizures and Spikes are easily detected and source localized to provide valuable information to the Neurologist and Neurosurgeons who are planning treatment. This talk will cover the complementary aspects of these two brain imaging techniques and how these techniques can be used to understand how your brain processes language, hearing, vision, sensory, and memory functions. Until recently the lack of the technology and computing power made it hard to perform computational analysis of the whole brain as well as to provide an assessment of the interconnectivity and functionality of the entire neural network. Examining the recorded electrical activity from many sensors around the brain lets us look at how the brain is sending and receiving information between multiple regions of the brain as well as how a brain disorder such as epilepsy can disrupt these networks and regions that provide basic sensory input for the brain. Finally, we summarize how neuroimaging can be used in the future to tailor individual brain treatments.