The effect of long-term specialized motor experience of the lower limbs on the moving rubber foot illusion

Past research revealed that specialized long-term motor experience in the upper limbs can result in individuals experiencing variants of the rubber hand illusion less vividly than those without such motor experience. However, it remained unclear whether specialized long-term motor experience had an impact on the experience of body ownership illusions involving the lower extremities. Therefore, a moving rubber foot illusion (mRFI) task (real and rubber feet moved identically for 90s), in addition to control conditions, were conducted with two groups of young adult females, one consisting of 24 exceptionally experienced dancers, and a second group of 25 non-dancers. We hypothesized that dancers would experience the mRFI less vividly than non-dancers. Dependent variables included (a) proprioceptive drift (cm), which is the change in the perceived position of the real foot as a result of experiencing a condition, and (b) a rubber foot ownership score, which assessed the ownership participants felt for the rubber foot following a condition. Both groups recorded significant proprioceptive drift toward the rubber foot as a result of the synchronous mRFI condition. Additionally both groups reported higher rubber foot ownerships scores following the synchronous mRFI condition than control conditions. However, the groups did not differ on proprioceptive drift or rubber foot ownership, suggesting that the mRFI was not influenced by long-term specialized motor experience of the lower limb in young women.