You may re-check the quality of the electrode connections at any time by turning the Impedance Meter mode of the EEG NeuroAmp on. Note that during that phase no EEG measurement is possible, because the measurement signals distort the EEG signals.

After you pressed the "Check Impedance" button, your neurofeedback software stops the session and waits until you press the button again. After five minutes, the EEG NeuroAmp will turn back into the previous mode by itself.