Improvements in the effectiveness and efficiency of Neurotherapy through the use of the Hilbert-Huang Transform in Neurodiagnostics and biofeedback practice.

In the last five years, there have been two very important breakthroughs in our understanding of EEG signals with implications for Neurodiagnostics and neurotherapy practice.
The first of these is the work of Robert T. Knight, and his group at Stanford, that have shown the importance of high gamma signals through their work on intracranial electrocorticography. These workers have also shown phase amplitude coupling between high gamma, and alpha, in visual processing.The second is the work of Ali Mazaheri and Ole Jensen on the visual word processing area, and mismatch negativity. This work has shown clear diagnostic differences between ADHD and non ADHD subjects, in the control of attention and Alpha and Theta amplitude before and after mistakes.

Unfortunately, normal EEG signals greatly suppress high gamma relative to intracortical (brain surface) signals. The low amplitude of high gamma in normal EEG is the single greatest restriction to the use of this new knowledge in neurotherapy practice.
We have now demonstrated that to some extent the low amplitude problem can be overcome by the use of the Hilbert-Huang Transform (HHT), instead of conventional EEG frequency decomposition. We have demonstrated that phase amplitude coupling is observable using the normal EEG signals. We have also shown improved efficiency in treatment when biofeedback is based on the HHT signal decomposition. Although this work is in its infancy, it has very high promise, particularly in areas relating to reading disability, but probably in all areas of neurotherapy.