The present invention relates to a system (100) for modifying a degree of relaxation of a person (10) using biofeedback. The system (100) comprises a first physiological parameter determining unit (20) for determining a first physiological parameter of the person (10), a reference parameter providing unit (60) for providing a reference parameter, a correlation determining unit (30) for determining a degree of correlation between the first physiological parameter and the reference parameter, and a controller (40) for determining a control information based on the determined degree of correlation, wherein the control information is adapted to control an output unit (50) for outputting an output signal for modifying the degree of relaxation of the person (10).