By activating the two cutaneous actuators 802A, 802B with a predetermined time interval, the user perceives motions or actions occurring within the user's body part 824 instead of the user's skin. For example, an illusory sensation such as (i) a bullet or projectile entering from a patch of skin and exiting through another path of skin, (ii) a virtual actuator vibrating inside the body part, (iii) a center point of motion moving gradually from one point to another, (iv) saltation occurring inside the body part can be generated. By controlling parameters such as the amplitude, timing and/or sequence of activation, the motion or action inside the user's body part 824 can be emulated.