California Institute of Technology

In three participants with tetraplegia imagining object manipulation, neural activity across several brain regions represented the configuration of the whole hand during imagined grasps. The posterior parietal cortex simultaneously encoded grasp and object properties, largely through distinct neuronal subpopulations. Grasp-related activity varied with motor planning versus imagined execution and with object presence versus absence; some regions also represented object shape during planning. The authors suggest that separating grasp and object information could support more stable BCI grasp control. However, the motor imagery task does not establish restored hand function or improved robotic grasp performance. The study is a preprint that has not been peer reviewed.

A preprint shows that functional ultrasound imaging (fUSI), read through an acoustically transparent cranial-window implant, reliably resolved multi-body-part and single-digit movement encoding in one participant's primary sensorimotor cortex, with maps consistent with classical somatotopy and single-trial decoding supported across sessions; analysis of key decoding voxels suggested different Brodmann areas encode single-digit movement differently. The researchers argue fUSI can map motor representations at submillimeter resolution, filling a key gap in humans between invasive electrophysiology and non-invasive blood-flow imaging; the work has not been peer reviewed.