Sensory Feedback

Researchers proposed an attention-driven hybrid interaction model combining brain-computer interfaces and virtual reality, then evaluated it in three rounds of user experiments. The study reported user experience comparable to traditional VR control methods. Named Attention-BrainVerse, the model combines attention-centered input, adaptive processing and visual feedback to address usability challenges. It uses dynamic thresholds and continuous difficulty adjustment, with feedback mechanisms including attention visualization. The reported comparison concerns user experience, not equivalence in neural decoding accuracy, operating speed or hardware cost.

Authors at the University of California, San Francisco and UC Berkeley discuss how continuous closed-loop reinforcement interacts with sensory feedback when people learn to control human-machine interfaces. The Neuron commentary covers BCIs, augmented reality devices and hand prostheses.

A collaboration involving Caltech recorded single-neuron activity in three participants with tetraplegia while applying vibration to a sensate upper-limb region. Primary somatosensory cortex responses tracked stimulus amplitude more closely, while posterior parietal activity was more strongly associated with perception and confidence. Only two participants provided confidence ratings. The preprint distinguishes associations with physical input and subjective perception; it does not establish that one brain region alone generates conscious touch.

Rats implanted with microwire arrays showed an exponential-like fall in intracortical microstimulation (ICMS) perception thresholds from weeks 5 to 12, then held near a fitted asymptote of about 1.1 nC/ph per electrode across 10 stimulating electrodes through week 30 in animals that retained detectable percepts. Correct responses to the conditioned stimulus stabilized at roughly 90%. Neither the arrays' electrophysiological nor their electrochemical properties explained the threshold trend across animals. Gene expression in implanted tissue showed elevated Gfap and Cd68 alongside reduced NeuN and Bdnf, consistent with earlier neuroinflammation findings. Two animals lost sensation over the 30-week period.

Researchers implanted an intracortical brain-computer interface in a participant with complete tetraplegia that reads movement intent from motor cortex to drive muscle electrical stimulation for grasping, while hand-mounted force sensors send touch information back by stimulating the sensory cortex. A separate channel pairs spinal cord stimulation with sensory input to promote neural plasticity. The participant could self-feed and pick up fragile objects. Improvements in elbow flexion strength and wrist sensation persisted after stimulation stopped, suggesting the system may be retraining neural pathways rather than only replacing them.

Purdue University researchers compared sparse and redundant intracortical microstimulation encoding in eight mice. Stimulating more electrodes simultaneously accelerated learning, shortened navigation trials and improved success rates and path efficiency when stimulation was combined with vision. The findings were released as a preprint.

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.