[Verse 1] Desert ant walks a crooked line to forage far from home, counts her steps like a metronome, no map, no GPS, no phone, that's dead reckoning, vector math running hot inside her skull, idiothetic cues — that's self-motion whispers, muscle pull and lull. Rodent spins a wheel in darkness, entorhinal cortex keeps the tally, grid cells fire in hexagons, tessellating every alley, humans blindfolded, walking loops, still return to where they started, path integration's the engine — before you're lost, you're charted. [Chorus] Integrate the motion, don't need your eyes to know it, grid cell hums a hex-shaped tune, step by step you show it, Steffenach snipped the wiring, watch the water maze go rotten, path without a compass — the map gets self-begotten. [Verse 2] Two thousand five, Steffenach took the knife to entorhinal tissue, rats still swam but lost precision, that's the lesion's issue, place cells trembled, stability shaken like a loose foundation, proof the cortex isn't decor — it's active computation. Fast forward, Gil in twenty-eighteen, cooling probes not cutting, silence the grid cells mid-task, watch the pathing start gutting, mice still reached the goal by cues but lost the shortcut feeling, inactivate the metric, and the hexagon stops dealing. [Chorus] Integrate the motion, don't need your eyes to know it, grid cell hums a hex-shaped tune, step by step you show it, Steffenach snipped the wiring, watch the water maze go rotten, path without a compass — the map gets self-begotten. [Verse 3] Hardcastle twenty-fifteen tracked the drift like a leaking clock, run without a landmark, and the hexagon starts to rock, error accumulates, variance climbing like a fever, then a wall, a corner, a beacon — resets the deceiver. That's the anchor point, snap the grid back into order, self-motion's a rough draft, vision is the border, without a fix the estimate wanders off like smoke in wind, landmarks are the eraser, integration is the pen. [Bridge] But hold up — maybe grids ain't just an odometer counting paces, McNaughton says universal ruler, measuring all the spaces, a metric for cognition, not tied to legs or wheels, distance, time, or even thought — the same lattice reveals, so is it the engine of the journey or the yardstick on the wall? Both readings hold some water — that's the argument, that's all. [Chorus] Integrate the motion, don't need your eyes to know it, grid cell hums a hex-shaped tune, step by step you show it, Steffenach snipped the wiring, watch the water maze go rotten, path without a compass — the map gets self-begotten. [Outro] Idiothetic whispers, landmark's loud correction, grid cells split the difference between drift and its detection, write the page, argue both sides, let the hexagon decide — path integration's the leading guess, not the final ride.
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