Abstract: A device assembly causes the concentration of a sportsperson in the course of a throwing, kicking, striking and shooting movement and/or the physical movement sequence to increasingly focus on feeling and thereby improve performance. The device assembly has a detector which transmits a signal to a pair of shutter spectacles via a transmitter at a selectable time between the beginning of a throwing, kicking, striking and shooting movement and/or the physical movement sequence and the movement phase commenced in this way. The shutter spectacles have a receiving circuit which converts the lenses of the shutter spectacles from a high transparency to a low transparency when said signal is received.