Restoring sight and touch: Could one brain-computer technology transform both?

For decades, scientists have pursued two ambitious goals: restoring vision to people who have lost their sight and returning sensation to people living with paralysis or limb loss. These challenges have largely been tackled as separate fields of research. However, a new review suggests the technologies underpinning both may be far more alike than previously recognised.

Researchers led by Giacomo Valle, Assistant Professor at Chalmers University of Technology in Sweden, argue that artificial vision and artificial touch systems have been evolving along remarkably similar paths for more than 50 years. Their findings, published in Nature Reviews Bioengineering, could help accelerate efforts to develop practical brain-computer interfaces (BCIs) capable of restoring lost sensory function.

Brain-computer interfaces work by creating a direct connection between the brain and external devices. Typically, tiny electrodes are implanted into specific regions of the cerebral cortex, allowing signals to be sent into or received from the brain.

In vision research, these devices are known as visual cortical prostheses (VCPs). They aim to restore some level of sight by stimulating the visual cortex and generating patterns of light or shapes that the brain interprets as visual information. Clinical trials investigating such approaches are already underway.

Meanwhile, somatosensory cortical prostheses (SCPs) seek to restore touch. These systems can create sensations of pressure, texture, movement or contact by stimulating regions of the brain responsible for processing tactile information. Similar clinical studies are investigating how these technologies can assist people with paralysis or advanced prosthetic limbs.

According to Valle, the surprising conclusion is that both technologies are essentially seeking to solve the same biological problem. “Natural vision and touch both collect complex information from the external world and convert it into electrical signals that the brain can understand,” explains Valle. “The engineering challenges are therefore remarkably similar.”

The review, titled Restoring vision and touch with cortical microstimulation, compares visual and tactile prostheses side-by-side for the first time. Historically, researchers working on blindness and those working on paralysis or sensory restoration have rarely interacted.

“People attended different conferences, worked in different hospitals and addressed different patient groups,” says Valle. “There has been parallel development in both fields, but very little cross-fertilisation of ideas.”

Moving beyond simple sensations

One factor driving convergence is increasing technological sophistication. Early sensory prostheses focused on generating simple experiences. For example, visual prostheses attempted to create dots of light, while tactile prostheses sought to generate basic feelings of touch.

Researchers are now attempting something much more ambitious. Instead of merely creating a sensation, scientists want artificial systems capable of reproducing complex sensory experiences. Interestingly, both vision and touch researchers are grappling with identical questions.

Valle explains that his own work on restoring tactile sensations led him to discover that vision researchers were solving many of the same computational challenges.

Companies such as Neuralink, Synchron and Precision Neuroscience have attracted global attention as they develop implantable brain interfaces designed to help patients communicate, control devices or restore lost function. Last year, researchers published findings in Science demonstrating significant advances in cortical stimulation and sensory restoration technologies, highlighting the accelerating pace of progress in neuroengineering.

As investment increases, experts believe that combining knowledge from different areas of sensory restoration could shorten development times and reduce duplication of effort.

A unified framework may also help researchers develop common hardware platforms capable of supporting multiple clinical applications.

Canadian neuroscience

Research institutions such as the University of Toronto, McGill University, the University of British Columbia and the Krembil Brain Institute have established strong programmes in neuroscience, neuroprosthetics and brain-computer interfaces. Canadian researchers have been particularly active in neuroengineering and advanced prosthetics.

Canada has also emerged as a leader in discussions around the ethical implications of direct brain interfaces, including privacy, autonomy and informed consent. These issues are becoming increasingly relevant as implantable technologies move closer to routine clinical use.

Yet somesignificant hurdles remain before sensory restoration technologies become widely available. Technical challenges include long-term electrode stability, reliable signal quality, and device durability.

There are also important ethical questions. For example: Who owns neural data?, How should brain-derived information be protected?, and What safeguards are needed to prevent misuse? Such debates are becoming increasingly prominent as neurotechnology advances from laboratory research into clinical practice.