Traditional approaches to Neurofeedback assume that effective training can only occur in frequency ranges that lie far away from standard sources of "noise" like wall current. In America this means isolating and removing the components of all signal near 60 Hz, whereas, in Europe it means isolating and removing the components of all signal near 50 Hz. However, with recent advances in both hardware and software, it is entirely possible to both detect and feedback shifts in these frequency ranges, if the correct signal detection procedures are used with robust enough computers and amplifiers. This means using 3rd or higher order JTFA-based denoising procedures with an amplifier that rolls off at 61 Hz or higher. JTFA or Joint Time-Frequency Analysis allows for the discernment of various forms of "noise" due to the particular signature of that noise within the joint time-frequency domain, while also preserving the particular characteristics of the EEG that share a frequency range. The NeuroCare Pro(c) Neurofeedback system contains such DSP (Digital Signal Processing) capabilities and was used for the training that will be described.
Beyond the obvious implications of an expanded target range, one can ask whether or not this particular DSP function is useful clinically - and the answer appears to be yes, at least in regard to what has been called "Electro-Smog" in Europe. A large body of clinical work has delineated there a pattern of immune dysfunction that seems to be induced and maintained by sustained contact with line current, which in Europe is 50 Hz. A particular EEG signature can be seen using the NeuroCare Pro(c) Neurofeedback system in clients suffering from "Electro-Smog" and the specifics of this pattern involve a diagonal, time-frequency based "ramping up" of activity along the frequency spectrum culminating in a rapid 50 Hz burst that is not correlated with shifts in the wall current. The signal is somewhat reminiscent of Doppler phenomenon and disappears with successful training. This precise sigature attenuates and/or disappears with effective neurofeedback, especially when a 50 Hz inclusive "inhibit" target is included.
Initial work on American subjects reveal this same pattern but centered around 60 Hz, rather than 50 Hz. Three important implications arise from this work: Signals at or near line current can be detected accurately with specific JTFA techniques and sufficiently powerful EEG amplifiers. Feeding back activity at or near line current can be very important in ameliorating or transforming particular clinical presentations. "Electro-Smog" may be characterized by a particular Joint Time-Frequency signature at or near the frequency value of line current in the environment in which the symptoms manifest.