BMED Press’ CEO Christopher Fisher, PhD recently interviewed Rex Cannon, PhD. The topics of this discussion included brain imaging technics, particuarly electroencephalography (EEG) and Low Resolution Brain Electromagnetic Tomography (LORETA) as well as LORETA neurofeedback, the future of EEG and LORETA, and more.
Dr. Rex Cannon has joint research assistant professorships in the Department of Psychology and Graduate School of Medicine at University of Tennessee. Dr. Cannon is a highly regarded and recognized EEG/LORETA researcher. He has published numerous scientific journal articles on these topics.
Dr. Rex Cannon recently wrote the first known book on LORETA. The book is entitled, “Low Resolution Brain Electromagnetic Tomography (LORETA): Basic Concepts and Clinical Applications,” which is published at BMED Press. This important book provides clinicians with the “missing manual” to LORETA. The book also discusses clinical applications of LORETA for specific disorders, such as depression and ADHD, and their treatment via LORETA neurofeedback.
For those unfamiliar with EEG and LORETA, could you provide a brief explanation of these brain imaging technologies?
Dr. Cannon: EEG or the electroencephalogram is the electrical activity of the brain recorded by a simple graphing technique or more complex computerized methods. LORETA is a method used to localize potential sources of the EEG on the scalp. I use cell phones as an example. First, we have satellites in space that orbit around the earth, so we will consider this path as a fixed boundary. Now let us pretend that every person on the earth has a cell phone (signal) and we want to locate one signal out of a potential 7 billion signals. We do have cell phone towers that form sectors and grids over the landscape of the surface (with potential non-signal areas included). In our search for this signal source, we must determine its unique signature as contrasted with all other signals globally and locally. We then triangulate and differentiate to a potential vector and considering the relationship with all surrounding signals we can find this particular phone signal from all other signals. You can watch this magical example on many crime solver shows on television.
How long have you been involved with EEG? In LORETA?
Dr. Cannon: I began working with EEG in my final year of undergraduate study in 2004. I first gained experience with LORETA in the same year and continued on to work with both Dr. Marco Congedo and Dr. Joel Lubar in the brain research and neuropsychology laboratory at UTK.
What was your motivation to write this book?
Dr. Cannon: In my experience it would have been great to have a click and point manual describing how to use the software as well as neuroimaging, EEG and source localization references to help interpret data in both experimental and patient data. I thought it would be fantastic to have such a reference. Thus, this was my purpose in writing the book.
Is EEG still relevant given the widespread availability of brain imaging technologies, such as FMRI, SPECT, etc.?
Dr. Cannon: Yes, in fact EEG is becoming more important to interpreting other imaging techniques. The uncertainty phenomenon does not just apply to EEG, it also applies to all imaging and statistical interpretations of data. This is our Achilles heel.
Is EEG outdated and inaccurate technology?
Dr. Cannon: EEG is not outdated. We do not know with any certainty how these frequencies function and interact within the brain, nor what they mean. Nothing can be irrelevant unless you fully understand it and can rule out its contribution to a particular phenomenon.
What are the advantages of EEG/LORETA?
Dr. Cannon: EEG and LORETA are resource-effective and with proper use can be used in a variety of contexts, including, diagnostic procedures, neurofeedback, monitoring medication effects and so on. It can also be used to monitor individuals longitudinally to evaluate specific changes in the EEG and its sources relative to particular syndromes. Currently, within the contexts of networks and neuroplasticity its advantages and uses are yet to be realized.
Can EEG/LORETA detect specific psychological/psychiatric disorders?
Dr. Cannon: I believe with careful techniques we can begin to detect and classify specific disorders. We are currently engaged in research with two such disorders: Anxiety and