The project aims to study how the human brain represents the dimension of the upper-limbs (upper-limb metric representation), a representation required for actions and interactions with the environment. In particular, we will focus on the role of reduced sensorimotor experience in altering this representation. Three experiments have been proposed. A first experiment will be dedicated to study the impact of sensorimotor decline, typically occurring during healthy aging, in altering the upper-limb metric representation in healthy older participants. In a second experiment, we will explore the possibility to restore those age-related changes through a sensorimotor stimulation based on a movement training performed with augmented body-related feedback. Finally, we will explore if reduced sensorimotor signals during sleep could affect the upper-limb metric representation at the awakening.