# Use of Covariance Analysis in Electroencephalogram Reveals Abnormalities in Parkinson's Disease
## 4 Results
### General Wavelet Profiles of Control and Parkinson's Disease Patients over 60 Years Old (>60)  
Figure 6 shows the general wavelet profiles of the groups >60. Figure 6A shows the global wavelet curves profile for CL >60 (\(n\) = 6 crossings per channel). A main \(\alpha\) brainwave was identified with a frequency value of 8.99 \(\pm\) 1.36 Hz and a power of 0.93 microV\({}^{2}\). A secondary \(\delta\) brainwave was also observed with a frequency of 2.52 \(\pm\) 0.46 Hz and a power of 0.33 microV\({}^{2}\). Figure 6B shows the main frequencies profile for CL >60; the representative brainwave was \(\alpha\), with frequency values of 8.48 and 8.99 Hz. The 8.48 Hz frequency was found in the Fp and F channels, while the 8.99 Hz frequency was found in the C, T and O channels. Figure 6C shows the power anomalies profile for CL >60; the Fp, T and O channels showed mainly positive anomalies with a mean power of 0.8, 1.2 and 0.6, respectively. Notably, in the T7 channel there is a significant positive anomaly, when compared to the Fp and O channels. The F, C and P channels had mainly negative anomalies with mean power values of \(-\)0.1, \(-\)0.8 and \(-\)0.7, respectively. The F3, F8 and T8 channels had reduced power anomalies near to zero. The anteroposterior gradient was observed from high to low power with slope of \(-\)0.03. The Fp, T and O channels were between 1.2 and 1.7 times higher than the F, C and P channels. Figure 6D shows the brainwave power for CL >60; the highest power was in the \(\alpha\) brainwave, the \(\delta\) brainwavehad almost a half of this wave and the \(\theta\) brainwave had one-third the power; the power values were 0.46 and 0.29 microV\({}^{2}\), respectively. Figure 5: The general wavelet profiles of CL and PD patients \(<\)60. (**A**) The global wavelet curves profile for CL \(<\)60. (**B**) The main frequencies profile for CL \(<\)60. (**C**) The power anomalies profile for CL \(<\)60. (**D**) The brainwave power profile for CL \(<\)60. (**E**) The global wavelet curves profile for PD patient \(<\)60. (**F**) The main frequencies profile for PD patient \(<\)60. (**G**) The power anomalies profile for PD patient \(<\)60. (**H**) The brainwave power profile for PD patients \(<\)60. Figure 6E shows the global wavelet curves profile for PD patients >60 (\(n\) = 10 crossings per channel). A main \(\delta\) brainwave was observed with a frequency value of 2.67 \(\pm\) 0.61 Hz and a power of 0.90 microV\({}^{2}\). A secondary \(\alpha\) brainwave was identified with a frequency of 8.99 \(\pm\) 2.41 Hz and a power of 0.49 microV\({}^{2}\). Figure 6F shows the main frequencies profile for PD patients >60; the representative brainwave was 5, with frequency values of 2.38, 2.52 and 2.67 Hz. Particularly, the P8 channel remained in the \(\alpha\) brainwave with a frequency value of 8.99 Hz. The 2.38 Hz frequency was mainly found in the Fp channels, the 2.52 Hz frequency in the left-frontal channels and the 2.67 Hz frequency was widely distributed in the C and O channels. Figure 6G shows the power anomalies profile for PD patients >60; negative anomalies were only found in the Fp channels with a mean value of \(-1.8\), while positive anomalies were observed in the T, P and O channels with mean power values of 0.2, 0.1 and 1.3, respectively. The F and C channels showed values near to zero. The anteroposterior gradient was observed from low to high power with a slope of 0.12. Figure 6: General wavelet profiles of CL and PD patients >60. (**A**) The global wavelet curves profile for CL >60. (**B**) The main frequencies profile for CL >60. (**C**) The power anomalies profile for CL >60. (**D**) The brainwave power profile for CL >60. (**E**) The global wavelet curves profile for PD patient >60. (**F**) The main frequencies profile for PD patient >60. (**G**) The power anomalies profile for PD patient >60. (**H**) The brainwave power profile for PD patients >60. Figure 6H shows the brainwave power for PD patients >60; the highest power was in the \(\delta\) brainwave.