Brain State Sharing

Is it possible to transfer someone’s mental state to another person through technology? Brain State Sharing is an experimental installation that tried exactly that: broadcasting the live EEG signals of a meditating person to volunteers — as flickering light and binaural sound.

The project grew out of the course “Messing with our Minds” (Willy Sengewald, FH Potsdam), built around a rare resource: real-time brain activity, streamed from an EEG recording device through MATLAB into Processing. Researching what one could do with a live feed of someone’s brain, we found brain machines — glasses with LEDs and headphones that pulse light and sound at fixed frequencies (16, 10, and 7 Hz) to nudge the brain toward relaxed, meditative states. The sound is binaural: the frequency difference between the left and right channel matches the target rhythm.

We first built an Arduino-driven brain machine ourselves — three LEDs on each side of a headphone bow — and ran self-experiments to see whether the effect was real. It was, more for some than for others, but reliably enough to design an experiment around it. That raised the actual question of the project: if stimulation can shape a brain state, can the measured state of one brain be passed on to others?

At the Lange Nacht der Wissenschaften at FU Berlin, the setup scaled up. One person meditated, wired to a 19-electrode EEG. Instead of building many wearable brain machines, we built one big one: a projector flashed the visual signal onto a large screen while the audio played through headphones. Three volunteers at a time sat on the back side of the screen, directly in the projector’s light, wearing diffuser masks we made from transparent spheres with embedded headphone shells. The audience saw only their silhouettes and dangling cables in the flickering light. During the afternoon tryouts, some visitors kept the brain machine on for twenty minutes, others gave up within one; during the broadcast itself, one volunteer fell asleep while the subject meditated.

A live visualization tracked the experiment: the 19 electrodes were laid out as on the head, each shown as a ring-and-pie chart of its dominant frequency band, with a running timeline of peaks and averages along the top — the data through which we watched meditation and machine influence each other. The setup also produced accidental biofeedback loops: while debugging the visualization wired to the EEG myself, I could watch my own brain react to seeing its own data.

For the semester finale the experiment moved into a fulldome. Four participants’ EEG data was translated into a 4×4 matrix, color-coded by the dominant wave type — beta, alpha, or theta — and tiled across the dome ceiling. The whole room pulsed with the subjects’ brain activity, which gave the projection itself a mildly hypnotic side effect.