An apparatus is described comprising electrodes (22) configured to be placed upon a portion of a body of a subject, and a user interface device (26). A computer processor (24) applies a neuromodulation treatment to the subject, by driving electrical pulses into the portion of the subject's body via the electrodes, and generates an output on the user interface device that indicates to the subject a physiological effect that the neuromodulation treatment has upon the subject's body.