Week Six - Day One
The poster is mainly completed except one part which was the addition of the graphs that showed the frequencies after the Fast Fourier Transform. The Python program was finished being adjusted to produce graphs that would display nicely. Before the graphs had axis's that would clump together and the graphs would all overlap each other. This was fixed by creating labels for the x-axis and y-axis to show the intervals. By coding the minimum value and maximum value, the intervals could be extracted by taking the difference between the two and finding every fourth one in that interval. This way all the numbers would be spaced out evenly and could easily adjust itself, which it wouldn't be able to do if it was hard coded instead.
By coding x = per[0][100:], a 2D matrix is created which says that the first row is the x-axis and their data points and then only the digits from 100 and beyond are plotted. This was done because when first graphing the points extracted from the Emotiv EPOC. there was possibly white noise and that created a spike that didn't have too much importance. This was called High-Pass Filter in which you filter out the high frequencies that distract from the low frequencies. Also, the frequency was changed to 128 which meant that the Emotiv EPOC recorded 128 brain signals in a second. That allowed the frequency (x-axis) to be changed from an interval of 0.5 to an interval of 70. That shows the full frequency and therefore we could see a small peak at 60 Hz. The small peak could be seen at both the FC5 and F8 which are near the frontal lobe and 60 Hz shows delta waves that mean concentration or focus which would make sense for the action of reading. Another difference found would be that the high peaks are found at the low frequencies for reading and found in the middle frequencies between 30 Hz and 40 Hz for watching cartoons. The band width frequencies show which waves (alpha, delta, theta, etc.) are active and that can be used to determine the action being done.
*Signal Processing with Neuroscience