4D technique promises new insights into brain function
January 23, 2009 It’s kind of ironic that the very organ that gives us our intelligence and understanding of the world around us is also the one we understand the least. Now a novel 4D colorimetric technique developed by researchers at Florida Atlantic University, (FAU), that simultaneously maps four dimensions of brain data, (magnitude, 2D of cortical surface and time), in EEG signals could dramatically change the way neuroscientists are able to understand how the brain operates. The technique makes it possible to observe and interpret oscillatory activity of the entire brain as it evolves in time, millisecond by millisecond, so that for the first time, true episodes of brain coordination can be spotted directly in EEG records and carefully analyzed.
For the brain to achieve its intricate functions such as perception, action, attention and decision making, neural regions have to work together yet still retain their specialized roles. Excess or lack of timely coordination between brain areas lies at the core of a number of psychiatric and neurological disorders such as epilepsy, schizophrenia, autism, Parkinson’s disease, sleep disorders and depression. Research carried out at FAU by Drs. J. A. Scott Kelso and Emmanuelle Tognoli demonstrates that coordination involves a subtle kind of ballet in the brain, and like dancers, cortical areas are capable of coming together as an ensemble (integration) while still exhibiting a tendency to do their own thing (segregation).
According to Kelso, “A lot of emphasis in neuroscience these days is on what the parts do, but understanding the coordination of multiple parts in a complex system such as the brain is a fundamental challenge. Using our approach, key predictions of cortical coordination dynamics can now be tested, thereby revealing the essential modus operandi of the intact living brain.” The researchers found that most of the time, activity from multiple brain areas look coordinated; however, in actuality, there is far less synchrony than what appears to be. For a long time, scientists have strictly emphasized one kind of synchronization called ‘inphase’ or ‘zero-lag synchrony’ looking only at who is coordinated with whom and not observing the details of how they are coordinated. Tognoli and Kelso have shown that the brain uses a much wider repertoire of synchronization patterns than just inphase - for example, brain areas may lock their oscillations together but keep a different phase.
“In the future, it may be possible to fluently read the processes of the brain from the EEG like one reads notes from a musical score,” said Tognoli. “Our technique is already providing a unique view on brain dynamics. It shows how activity grows and dies in individual brain areas and how multiple areas engage in and disengage from working together as a coordinated team.” In addition to shedding insight on the way the brain normally operates, Tognoli and Kelso’s research provides a much-needed framework to understand the coordination dynamics of brain areas in a number of psychiatric and neurological disorders thereby opening up new ways to study therapeutic interventions, in particular the effects of drugs.
In article detailing Kelso and Tognoli’s research titled, “Brain coordination dynamics: true and false faces of phase synchrony and metastability,” was published in the January 2009 issue and featured on the cover of Progress in Neurobiology.