Figure 6
Transcranial electric stimulation setup and electrode impedance. (a) Block diagram of the step from personal computer to electrodes, showing a plate electrode on mastoid and a gold-plated tiptrode in the ear canal. The red circle represents a transformer power supply to isolate the power line from the subject and the green rectangle represents a monitoring oscilloscope. (b) Impedance for plate-to-plate electrodes as a function of stimulus frequency (x-axis) and stimulus level (symbols). (c) Impedance for different electrodes (symbols) as a function of stimulus frequency (x-axis) at a fixed 0.1-mA stimulus level.
