Please note: This type of neurofeedback training has limited scientific evidence and at this stage is not considered an efficacious treatment for any specific disorders.
What is Z-score training?
Live-score Z-score training usually utilises two, four or more electrodes on the head. Continuous calculations are being computed comparing the way that the brain is functioning on different variables (e.g., power, asymmetries, phase-lag, coherence) to a scientifically developed normative database.
The Z-score system compares this with a database and provides feedback to the client to ‘shift’ their EEG profile toward a ‘normal’ profile.
This feedback consists of observing a DVD reel, where the quality dims and flickers when the person is not performing well and becomes clear and brighter when his/her brain waves are functioning closer to the norms.
Important things to note:
1. The only database available for z-score is the American database, which limits the generalisation to other populations.
2. It trains towards eyes open norms or eyes close norms only. Many times, we see clients whose eyes open and eyes close QEEG are normal. But when they exert mental effort, the abnormality in their EEG appears.
3.Training towards the “norm” may benefit those who are low functioning, with EEG characteristics that are way below the norm. However, certain high functioning brains with special talents can also have characteristics far from the “norm”. As such doing a z-Score training may negate these talents.