Sensory Feedback

A University of Pittsburgh team (Bose et al.) tested the crossmodal congruency effect (CCE) task in 15 able-bodied volunteers to see whether it can quantify how intuitive lower-limb sensory feedback feels. At the knee, the task distinguished more natural pneumatic stimulation from less natural electrical stimulation; at the foot, it could not tell the same stimuli apart. The study was posted to bioRxiv on August 10, 2026. Lower-limb amputees often have balance and gait problems because their prostheses give no somatosensory feedback; electrical-stimulation neuroprostheses can partly restore sensation, but there has been no way to quantify how intuitive that sensation is. The authors stress that external factors affecting the CCE must be identified before it can be used with amputees.

An early feasibility study followed five people with spinal cord injury, each implanted with two Blackrock NeuroPort arrays in somatosensory cortex. Across two to 10 years of implantation, more than 168 million intracortical stimulation pulses were delivered over 27 combined implant-years without a serious adverse event or direct harm to electrode health. An average of 64% ± 13% of electrodes still evoked touch, including 60% after 10 years in one participant.