The faces of others are selectively revealed based on how similar their brainwaves are to the wearer. As two people's brainwaves align, the line of sight between them is clear; but as the wavelengths move apart, the faces are obscured and fade into black.

Mental Block rotates a large polarized filter disk suspended in front of the wearer's face. The angle of the disk is determined by each wearer's brainwaves. When one disk is parallel to another person's disk, light passes through unobstructed and two people can see each other. Perpendicular disk alignment corresponds to brainwaves at opposite ends of the spectrum, or in other words, total obscurity. More subtle brainwave differences are mapped on the gradient between visibility and obscurity.

Mental Block was a final project for Tom Igoe's and Rory Nugent's Physical Computing classes at ITP. The project was displayed at the 2009 ITP Winter Show.

We were dubious about the representational content of our brain wave data — the EEG chipset manufacturer describes the values as "attention" and "meditation" — but in practice, we could not reliably navigate these states with our thoughts. Instead of clinging to the idea of mapping mental affect directly to an acoustic or visual response, we decided to represent the differences in readings between individuals. This approach remains relatively agnostic to what the data might mean, and instead attempts to visualize divergence (or affinity) between two people's brain waves.

Mental Block reads the user's Alpha and Beta waves. It translates the Alpha waves to illumination on the wearer's face. The more mentally present, the brighter the wearer's face. Beta waves are translated to the rotation of a polarized filter disk. If both wearers' beta waves are on the same frequency, they can see each other clearly. The more the wearers' mental states differ from each other, the more obfuscated their faces become from each other.

There are a few applications for brain-control interfaces that we wanted to explore: a performative application, a meditative one and a fun, user-oriented one. This links to the other implementations are See You See Me and Brain Radio.

The GearThe Gear