[Verse 1] Fold inward where the hemispheres kiss, a medial wedge the surgeons almost miss, precuneus, cousin to the cingulate's bend, burning fuel like it's got no end. Cavanna and Trimble read the whole chart, glucose pouring in, an effulgent part — glowing hotter than the cortex nearby, picturing mazes with your mind's own eye. Visuospatial sketches, episodes you retrieve, the self looks inward here, hard to believe one gray patch holds your whole autobiography, self and scene and memory. [Chorus] Front is touch, middle is thought, back is sight, precuneus wears three faces, none of them quite right, anterior moves, posterior sees, the center sits and schemes, Margulies drew the gradient, the map of hidden streams. Precuneus, precuneus, quiet hub of me, three zones folded into one, a triptych none can see. [Verse 2] Draw a line from the crown toward the heel, anterior strip answers to the body's feel, sensorimotor whispers, posture and the limb, while the posterior sliver keeps its eye on the rim, wired to the visual cortex, watching color and the edge. Middle ground's the busiest, perched upon the ledge, cognitive and associative, shaking hands all day with prefrontal cortex and the parietal lobe's relay. Monkeys showed the same design, Margulies confirmed, primate brains and human brains, the gradient's pattern learned. [Chorus] [Verse 3] Parvizi went hunting in the macaque's own head, traced posteromedial cortex, here's what the tracer said: heavy wires to association cortex, thalamus, claustrum too, but a whisper-thin connection to the primary view — barely speaks to the touch map, barely to the motor band, this hub prefers the abstract over the feel of a hand. [Verse 4] Slide electrodes under skull, Dastjerdi took the chance, Foster watched the posteromedial cortex dance — high frequency fireworks the instant memory wakes, autobiography unspooling like a palimpsest it makes, old scenes bleeding faintly through the page that's freshly penned. But hand this region arithmetic, and watch the signal end — suppressed the second numbers come, a silence clear and stark, the fingerprint of the default mode, caught cold in the dark. [Bridge] Gusnard and Raichle traced the glow to the waking, thinking frame, Vogt and Laureys watched it dim when consciousness lost its name. Coma, vegetative stillness, hypometabolism's creeping shade, Alzheimer's dims this furnace first before the memory starts to fade. Where the glucose used to flood, now the shadows softly fall, the dimming of this quiet hub is the dimming of it all. [Chorus] [Outro] Front, middle, back — a hub of layered song, precuneus keeps your story threaded all along, remember the gradient, remember the glow, the self stays lit here long after you go quiet and slow.
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