Using the headset can be experienced differently among different people. Some people don’t feel anything underneath the electrodes. Some have a comfortable experience.
Some people feel an itchy, slightly tingling sensation. Like a stinging or a mild burning sensation on the forehead. Typically, sensations vary among sessions. It usually feels a little more intense during the first 3 minutes.
A number of factors will affect how you experience Flow, for example, sleep quality and skin sensitivity.