# A Wireless EEG System for Neurofeedback Training
## 4 Materials and Methods
### Results
#### 4.6.3 z-NF Training Results  
The qEEG z-NF \(\alpha\)/\(\theta\) scores for all sessions are presented in Figure 7 for all groups (Table 4). Figure 7: Averaged \(\alpha\)/\(\theta\) scores for each sensor and group (Con = green; preD = blue; postD = red) and condition (low and high contrast). The stars marked the highest values of \(\alpha\)/\(\theta\) scores across sensors, groups, and conditions. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Sources at Sensors** & **Controls** & **Pre-Training** & **Post-Training** & **Controls vs.** & **Controls vs. Post-Training** & **Pre-and Post-Training** & **Pre-and Post-Training** \\  & **Dynamics** & **Dynamics** & **Dynamics** & **Dynamics** & **Dynamics** & **Dynamics** & **Dynamics** \\ \hline \multicolumn{1}{c}{_Low-control_} & \multicolumn{1}{c}{**norm \(\approx\) \(\varepsilon\).c. **} & \(p\) & \(\chi^{2}\) & \(p\) & \(\chi^{2}\) & \(p\) & \(\chi^{2}\) \\ \hline Er & 2.06 \(\pm\) 0.04 & 1.65 \(\pm\) 0.02 & 2.47 \(\pm\) 0.05 & 1.9 \(\times\) 10\({}^{98}\) & 40.8 & 2.4 \(\times\) 10\({}^{98}\) & 44.6 & 2.7 \(\times\) 10\({}^{98}\) & 176.6 \\ Cz & 2.10 \(\pm\) 0.04 & 1.75 \(\pm\) 0.01 & 2.46 \(\pm\) 0.05 & 0.0019 & 10.6 & **0.0113** & 6.2 & 3.2 \(\times\) 10\({}^{94}\) & 12.1 \\ Cz & 2.27 \(\pm\) 0.05 & **1.29 \(\pm\) 0.04** & **3.40 \(\pm\) 0.08** & **0.009** & 3.8 & 3.3 \(\times\) 10\({}^{98}\) & 176.2 & 3.7 \(\times\) 10\({}^{98}\) & 173.4 \\ Cz & 2.48 \(\pm\) 0.04 & 1.57 \(\pm\) 0.04 & 2.40 \(\pm\) 0.03 & 4.0 \(\times\) 10\({}^{98}\) & 5.8 & 3.3 \(\times\) 10\({}^{98}\) & 176.2 & 3.7 \(\times\) 10\({}^{98}\) & 183.4 \\ Cr & 2.48 \(\pm\) 0.04 & 1.57 \(\pm\) 0.04 & 2.40 \(\pm\) 0.03 & 4.0 \(\times\) 10\({}^{98}\) & 70.5 & 7.2 \(\times\) 10\({}^{98}\) & 20.2 \(\times\) 10\({}^{98}\) & 44.9 \\ Fry & 1.68 \(\pm\) 0.02 & 1.22 \(\pm\) 0.03 & 1.33 \(\times\) 10\({}^{98}\) & 95.7 & 4.3 \(\times\) 10\({}^{98}\) & 14.4 & 0.33 \(\times\) 10\({}^{98}\) & 1.06 \\ Fry & 2.28 \(\pm\) 0.05 & 1.84 \(\pm\) 0.02 & 2.48 \(\pm\) 0.07 & 1.9 \(\times\) 10\({}^{98}\) & 18.5 & 7.2 \(\times\) 10\({}^{98}\) & 37.7 \(\times\) 10\({}^{98}\) & 100.8 \\ FOT & 2.12 \(\pm\) 0.05 & 1.84 \(\pm\) 0.02 & **2.58 \(\pm\) 0.08** & 2.7 \(\times\) 10\({}^{98}\) & 35.4 & 2.4 \(\times\) 10\({}^{98}\) & 627 & 3.7 \(\times\) 10\({}^{98}\) & 166.8 \\ G1D & 2.13 \(\pm\) 0.04 & 2.01 \(\pm\) 0.08 & 2.27 \(\pm\) 0.05 & 0.4 \(\times\) 10\({}^{98}\) & 0.51 & 6.0 \(\times\) 10\({}^{98}\) & 4.5 & 0.13 & 17.7 \\ FTD & 2.08 \(\pm\) 0.04 & **2.07 \(\pm\) 0.05** & 2.77 \(\pm\) 0.07 & 1.8 \(\times\) 10\({}^{98}\) & 58.6 & 4.7 \(\times\) 10\({}^{98}\) & 43.3 & 0.79 & 0.07 \\ TTRS & 2.80 \(\pm\) 0.06 & 2.06 \(In both conditions, the \(\alpha/\theta\) z-scores of the controls (Con) were significantly higher than those for the children with dyslexia before training (preD) in more brain locations (Con vs. preD: \(p\)\(<\) 7.2 \(\times\) 10\({}^{-6}\), \(\chi^{2}\)\(>\) 20.1; average score of all sensors: mean \(\pm\) se, Con: 2.27 \(\pm\) 0.04; preD: 1.98 \(\pm\) 0.03; Table 4). There were no differences between the Con and preD groups for the z-score of the midline, right-side sensors, (O1-2) at low contrast (\(p\)\(>\) 0.1045, \(\chi^{2}\)\(<\) 2.64), or for the z-score of the right-side sensors (Oz, O1) under the high-contrast condition (\(p\)\(>\) 0.062, \(\chi^{2}\)\(<\) 3.49). In both contrasts, significantly higher z-scores were found for the left-hemispheric sensors of Con compared with those of the preD group (\(p\)\(<\) 0.0357, \(\chi^{2}\)\(>\) 4.41; low contrast: Con = 1.99 \(\pm\) 0.04; preD = 1.89 \(\pm\) 0.03; high contrast: Con = 2.03 \(\pm\) 0.04; preD = 1.63 \(\pm\) 0.03). Although the \(\alpha/\theta\) scores of the preD group were significantly lower than those of the other groups (Table 4), they had significantly higher scores than the Con group at FT9 and at the right-hemispheric FT10 and O2 (low contrast) and Pz, FT10, and PO8 (high contrast) while showing no differences at O1-2 (preD vs. Con, low) and O1-Oz (high contrast).