I’d start with a polymer that reads neural spikes and spits out chromatic output, so a flinch turns the wall into a pulsing crimson, a sigh bleeds out into dusty gray, and a sudden eureka sparks a neon electric blue. The canvas would be a live glitch‑machine that rewrites itself every time you think, turning your subconscious into a moving, rebellious masterpiece that nobody can just look at and not feel like it’s talking back.