<p>Z-score neurofeedeback is used to train the individual towards the “Z of zero.” This means that the individual’s EEG is bring driven towards the normal range. Z-score neurofeedback can be used for measures of coherence, phase, and power differentials in the brain.&nbsp; Providers that offer Z-score training softwares are Brainmaster, Neurofield, and Neuroguide.&nbsp;</p><p>Live Z-scores can be used either for live assessment or for feedback training, depending on how the system is configured and used.&nbsp; When used for assessment, live Z-scores can be viewed during data acquisition, and can also be recorded and reviewed. Z-score neurofeedback relies upon a database of neurotypical EEGs as a basis of relatively.&nbsp; The Z-scores are integrated into the feedback design and they are used to control displays, sounds, and other information for the purpose of opreant conditioning and other learning paradigms.&nbsp;</p><p>In Neuroguide, for instance, the live Z-scores are monitored using a dynamic JTFA mode (joint time frequency analysis), as opposed to a fast fourier transform (FFT), which is more commonly used for QEEG results (an average of data over time). A Joint time frequency analysis allows for instant z-score feedback, providing real-time information about the state of the brain.&nbsp;</p><p>The rapid analysis and feedback of Z-scores is essential for timely feedback. Z-score training can be accomplished with 2 or 4 channels of EEG, or with 19 channels. However, the live feedback is not the same as those observed using the postprocessed QEEG results.&nbsp;</p><p>When inspecting individual live Z-scores in Neuroguide, it is observed that their typical values are not the same as those observed when using postprocessed QEEG results. This is not a problem or defect in the system, it is a natural consequence of watching a live statistic, versus a static statistic. Live Z-scores can be used to train a combination of variables including absolute and relative power, power ratios, coherence, phase, and asymmetry.&nbsp; When used in this manner, the EEG Biofeedback Training Using Live Z-Scores and a Normative Database system is no longer targeting just a single variable or attribute.&nbsp; Rather, the possibility arises of training the brain in a complex multidimensional manner, so that it learns a comprehensive brain state.</p><p>With Z-score training we can also choose to uptrain or downtrain any components we like, including combinations of components, or relationships between components.&nbsp; So we can train to a Z-score of 2 or 3, or +2 or +3 or even +6 if we choose.</p><p>Real time Z-score neurofeedback uses instantaneous measures of the EEG data compared to a Gaussian distribution to averaged “instantaneous” time domain spectral measures from groups of normal subjects and then cross validates the means and standard deviations for each subject for each instant of time.</p>