Transfer of calibration between hand and foot: functional equivalence and fractal fluctuations

Transfer of competency in a perceptual task often depends on shared information between anatomically different perceptual subsystems. The problem of studying transfer involves isolating conditions of similarity and then trying to account for any resulting differences in transfer. To respect this twofold aspect, this article takes a two-pronged approach to transfer in dynamic touch. The present research first tests the hypothesis that functional equivalence supports the transfer of dynamic touch. Participants were trained to wield unseen objects with the hand or foot and were then tested on anatomically disparate limbs (i.e., the foot or hand, respectively). Next, we examined motion capture of these wielding behaviors for predictors of any asymmetry in transfer. Temporally fractal fluctuations of exploratory behavior can modulate information detection, and we tested whether the fractality of wielding might predict asymmetries in transfer across disparate limbs. Results suggest that transfer of training to anatomically disparate limbs respects functional conditions of similarity and also that the degree of temporally fractal fluctuations predicted limb differences in transfer.