This week was about the excursion to Aalto behavior laboratory to see a live demo on EEG. Setting up the measurement setup was interesting. I was expecting some kind of salt water sponges to be inserted under the electrodes, but the conductive gel application seemed much more practical in the end. We did a short measurement on reaction time when the test subject was given a visual or aural stimulus.
It was also interesting to do another kind of course assignment related to the measurement by analyzing some of the EEG butterfly plots and topographical maps. Having not done this before took me some time to figure out how to read the graphs and figure out what I was looking specifically in those graphs. Yet the results were in a way kind of fascinating demonstration of visualizing what happens in the brain when we interact with the world.
Watching the noise level on signal made me think that how many variables actually play into setting up the experiment. Considering if all the mechanical factors are eliminated or disregarded being the same every time and the only ones originating from the test subject itself were counted, I wonder how much their mental state or alertness of that time plays into the signal or the end up affecting the data. Or let’s say if the same person would perform 10 measurements during various times, how much the results differ during each time?