Now that I’ve got the ear clip unipolar EEG set up, I’m finally ready to record. I have my subject wear two headbands: one around the head like a normal sweatband and one under the chin and over C3 like in my previous experiments. I had to do a quick test to get the polarity of the electrodes labeled, but now I’ve got a decent setup working. Positive electrode goes over C3, negative goes on the occiput, and the ground gets clipped to the ear. The subject also wears an anti-static cuff, with the alligator clip attached to the barrel jack of the Heart and Brain shield. Here is some preliminary data:
It’s been a good week! Still plenty of work left to do, since there are some issues with alpha waves, and the RP tends to peak slightly after the action itself. Still, this is some exciting progress. I’m using Audacity to manually crop out epochs that occur during enormous DC spikes that max out the recording software. These huge spikes are obviously not EEG data and probably static discharge or issues with grounding. I’m currently working on writing some MATLAB code to automatically remove these trials consistently.
The next step is to verify these initial results using a lot of additional trials. Also I plan to add two more EEG channels to provide some spatial data about the propagation of the readiness potential.
By Patrick Glover