@article {TakagiENEURO.0095-19.2019, author = {A. Takagi and H. Kambara and Y. Koike}, title = {Increase in Grasp Force Reflects a Desire to Improve Movement Precision}, volume = {6}, number = {4}, elocation-id = {ENEURO.0095-19.2019}, year = {2019}, doi = {10.1523/ENEURO.0095-19.2019}, publisher = {Society for Neuroscience}, abstract = {Grasping is an action engraved in the human genome, enabling newborn infants to hang from a monkey-bar immediately after birth. The grasp force provides rich information about the brain{\textquoteright}s control of arm movements. In this study, we tested the hypothesis that the grasp force increases to improve the hand{\textquoteright}s movement precision during reaching. In two reaching experiments, subjects increased grasp force to suppress movement imprecision that arose from both self-generated motor noise and from an unpredictable environment. Furthermore, the grasp force did not increase constantly, but increased specifically along the movement where the hand{\textquoteright}s deviation was greatest. The increased grasp was premeditated and was not a reaction to environmental forces, suggesting that the central nervous system has a predictive, state-dependent model of movement precision during reaching. The grasp force provides a high temporal resolution and calibration-less estimate of movement precision adaptation.}, URL = {https://www.eneuro.org/content/6/4/ENEURO.0095-19.2019}, eprint = {https://www.eneuro.org/content/6/4/ENEURO.0095-19.2019.full.pdf}, journal = {eNeuro} }