- Experiment 1: Participants will have electrodes placed on the left side of their heads, and will be asked to say aloud as many words as they can think of that begin with certain letters. After the high-density DC polarization current is turned on and run for 10 minutes, participants will say words beginning with a different set of letters and perform reaction time and thinking speed tests. Some participants will receive real polarization and others will not, although all participants will be told that they are receiving the polarization.