Calculating Coherence Levels



Hi there,

In the Neurofeedback literature, there is a term which is known as “Coherence” which is “the measure of the amount of information sharing between two sites. Technically, it is a measure of the amount of measure of how stable the phase relationship is over time. There are many clinically relevant situations in which coherence and phase abnormalities are important. And it is possible for either hyper-coherence or hypo-coherence to introduce symptomatic deviation or a clinical concern (for instance, a hyper-coherent state may indicate excessive dependence between sites and lack of differentiation. Therefore, hyper-coherence may, at times, be seen in clients with impaired cognitive abilities.(…)” (Technical Foundations of Neurofeedback - Thomas F. Collura ).

As far as I could understood, the only method so far for calculating coherence is using FFTs in some math formulas. I am still a newbie on the SDK tools for Windows, but could someone tell me if FFTs in real time are available? Another thing: does anyone knows another method for calculating coherence that does not uses FFTs? (Let’s say, for instance, would it be possible to calculate the coherence levels with the alpha beta gamma etc power results??)

Thanks in advance!