John O’Keefe discovered place cells in the hippocampus in 1971 — neurons that fire only when the animal occupies a specific location. May-Britt and Edvard Moser discovered grid cells in 2005 — neurons in the entorhinal cortex that tile the environment in a hexagonal lattice. Together they form the brain’s biological GPS. The 2014 Nobel Prize in Physiology or Medicine recognised the discovery.
But the hippocampus does not limit itself to navigation. The same circuitry indexes episodic memory. Remembering feels different from navigating, but the underlying substrate is the same. This is why the ancient method of loci (memory palace) works — it exploits circuitry that was already doing the job.
Memory athletes using the method reliably outperform controls with effect sizes around d = 0.88. Fluera’s infinite canvas is a memory palace you build with your hands — and every node on it is spatially indexed by the same circuitry.