Brain waves came to mind immediately. (Pun intended.) What better to capture the intersection between biological life and mental experience?
Brain waves, recorded from the surface of the head, measure the electrical activity across local populations of cells inside the brain, neurons, as they exchange signals. Brainwaves were first recorded in humans in the early 1900s[1]. Those early recordings showed the brain is continuously active, even when individuals are resting or sleeping. The pioneering findings have important implications for understanding that activity, underpinning mental experience, does not originate from stimulation from the external environment but instead results from the interplay between incoming external stimulation and the ever-changing internal state of the brain.
I imagined the squiggly lines reflecting the ebb and flow of voltage recorded from the scalp etched along the façade. The idea pleased me, though I worried that the grooves might accumulate grime and cause ugly streak marks to develop over time. Maybe there was a clever way to fill in the etchings with a contrasting material, like a marbling effect. That could work. But the architect, Ingo Braun, had a much better idea. Rather than writing the brain waves into the façade, we could flip them around and use them to undulate the vertical dimension of the façade, like the draping of a curtain. How odd, I thought. But, yes, perfect.
[1] Berger, H. (1929). Über das elektrenkephalogramm des menschen. European archives of psychiatry and clinical neuroscience, 87(1), 527-5
Adrian, E. D., & Matthews, B. H. (1934). The Berger rhythm: potential changes from the occipital lobes in man. Brain, 57(4), 355-385.