In this study, we have investigated the sensorimotor and visuomotor learning of manual torque control when lifting an object with an eccentric weight distribution with the ipsilesional hand in patients with chronic stroke. Unexpectedly, we found that the torque resulting from grip force being applied at different vertical finger positions was biased depending on the location of the center of mass (CoM) of the lifted object in patients with left-hemispheric- and, to a lesser degree, also right hemispheric stroke in favor of an ipsilesional CoM when having to rely on sensorimotor memories. This finding is consistent with a shift of sensorimotor attention and intention away from a deflection to the contralesional- and towards the ipsilesional object side and could represent evidence for an object-centered reference frame of premotor neglect in basic object manipulation.
Schneider, T. R. & Hermdörfer, J. (2022). Object-centered sensorimotor bias of torque control in the chronic stage following stroke. Scientific reports. doi.org/10.1038/s41598-022-18754-z