The brain's backdoor

At the University of Wisconsin-Madison, neuroscientist Paul Bach-y-Rita challenged a fundamental notion of how the brain works. His research provided some of the first experimental evidence for neuroplasticity—the idea that the adult brain can reorganize itself. This led him to pioneer the field of sensory substitution. If one sense is lost, he reasoned, could another be rerouted to take its place? The answer was a device that allowed blind individuals to perceive visual information through their tongues.

The system, eventually commercialized as the BrainPort V100, consists of three parts: a small video camera mounted on a pair of glasses, a handheld controller, and an intra-oral device (IOD). The camera captures the scene in front of the user. The controller, about the size of a mobile phone, converts the video feed into a low-resolution, grayscale image. This image is then translated into patterns of electrical stimulation. These pulses are sent to a square grid of electrodes on the IOD, a small plastic paddle placed on the tongue. Early research prototypes used a 12-by-12 grid of 144 electrodes to "draw" the visual information onto the tongue's surface. Bright pixels from the camera image correspond to strong pulses, while dark pixels result in weaker pulses or no stimulation at all. Users initially describe the sensation as feeling like sparkling water or champagne bubbles.

Repurposing the visual cortex

The true work happens inside the brain. With training, the brain learns to interpret these tactile patterns as spatial information. Functional imaging studies show that while a sighted person's brain processes these tongue sensations in the somatosensory cortex (responsible for touch), a blind person's brain routes them to the visual cortex. The part of the brain that normally processes light from the eyes gets repurposed to interpret touch signals from the tongue. This adaptive reorganization is a direct example of cross-modal plasticity.

After about 10 hours of structured training, users are no longer consciously aware of the tingling on their tongue. Instead, they perceive the outlines and shapes of objects in the space in front of them. The experimental subjects at UW-Madison and in subsequent studies learned to perform remarkable tasks. They could distinguish between different objects on a table with 80% accuracy, navigate hallways, and even catch a ball rolled towards them. The technology is not a replacement for sight, is an augmentation—an entirely new data stream for the brain to learn and use. The research that began at UW-Madison led to the formation of the company Wicab, Inc. in 1998 and eventual FDA approval for the BrainPort V100 device in 2015.

Practical Information

Opening Hours

This location marks the University of Wisconsin-Madison, where the foundational research occurred. The campus grounds are open to the public, but the specific research labs, formerly known as the Tactile Communication and Neurorehabilitation Laboratory (TCNL), are not a public attraction.

Admission

Free to walk the campus.

Accessibility

The university campus has paved pathways and is generally accessible, though some areas may have inclines.

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Seeing with a 144-Pixel Tongue

The brain's backdoor

Repurposing the visual cortex

💡Fun Facts

References

There's more in the app

Practical Information

Seeing with a 144-Pixel Tongue

The brain's backdoor

Repurposing the visual cortex

💡Fun Facts

References

There's more in the app

Practical Information

Nearby curiosities

Nearby curiosities