RT Journal Article SR Electronic T1 Symmetric Intralimb Transfer of Skilled Isometric Force Production JF bioRxiv FD Cold Spring Harbor Laboratory SP 491415 DO 10.1101/491415 A1 Rajan, Vikram A A1 Hardwick, Robert M. A1 Celnik, Pablo A YR 2018 UL http://biorxiv.org/content/early/2018/12/11/491415.abstract AB Motor control theories propose that the same motor plans can be employed by different effectors. Skills learned with one effector can therefore ‘transfer’ to others, which has potential applications in clinical situations. However, evidence from visuomotor adaptation suggests this effect is asymmetric; learning can be generalized from proximal-to-distal effectors (e.g. arm to hand), but not from distal-to-proximal effectors (e.g. hand to arm). We propose that skill learning may not be subject to this asymmetry, as it relies on multiple learning processes beyond error detection and correction. Participants learned a skill task involving the production of isometric forces. We assessed their ability to perform the task with the hand and arm. One group trained to perform the task using only their hand, while a second trained using only their arm. In a final assessment, we found that participants who trained with either effector improved their skill in performing the task with both their hand and arm. There was no change in a control group that did not train between assessments, indicating that gains were related to the training, not the multiple assessments. These results indicate that in contrast to visuomotor adaptation, motor skills can generalize from both proximal-to-distal and distal-to-proximal effectors. We propose this is due to differences in the processes underlying skill acquisition in comparison to visuomotor adaptation.New and Noteworthy Prior research indicates that motor learning transfers from proximal-to-distal effectors, but not vice-versa. However, this work focused on adapting existing behavior; we questioned whether different results would occur when learning new motor skills. We found that the benefits of training on a skill task with either the hand or arm transferred across both effectors. This highlights important differences between adaptation and skill learning, and may allow therapeutic benefits for patients with impairments in specific effectors.Author ContributionsRMH, VAR, and PAC conceived the study. VAR collected the data. VAR and RMH analyzed the data. RMH drafted the manuscript. RMH, VAR and PAC finalized the manuscript.