[Verse 1] Deep in the midbrain where the ancient circuits dwell Lives a structure with a story evolutionists tell The Superior Colliculus, layered and wise In fish it's called tectum, the master of eyes Two levels of function stacked neat and clean The most primitive vision machine you've ever seen [Chorus] SC maps the world in layers, superficial and deep Retinotopic on top where the visual signals keep Motor maps below drive the saccades that leap Fast reflexes guard you even when you sleep Superior Colliculus, ancient and true Spinning your eyeballs to capture the view [Verse 2] The shallow layers paint a picture precise Every spot on your retina gets mapped out nice Point to point like a blueprint of sight But venture deeper and you'll find something bright Motor neurons fire when targets appear Commanding quick saccades to bring objects near [Chorus] SC maps the world in layers, superficial and deep Retinotopic on top where the visual signals keep Motor maps below drive the saccades that leap Fast reflexes guard you even when you sleep Superior Colliculus, ancient and true Spinning your eyeballs to capture the view [Bridge] Sound and touch join the party down low Multisensory fusion puts on quite a show Head coordinates, eye coordinates align When danger approaches, the response is divine Blindsight patients can point to what they can't see Their cortex is broken but SC runs free [Verse 3] Orienting responses happen lightning fast Before consciousness knows, the moment has passed Salient stimuli trigger the dance Of microsaccades in a reflexive trance From optic tectum to colliculus grand Evolution's gift helps survival withstand [Verse 4] Inhibition and excitation compete in the race Each neuron voting for where eyes should place Winner takes all in this neural debate While losers are silenced to seal their fate The built-in GPS of your visual brain Keeps tracking on target through sun and through rain [Chorus] SC maps the world in layers, superficial and deep Retinotopic on top where the visual signals keep Motor maps below drive the saccades that leap Fast reflexes guard you even when you sleep Superior Colliculus, ancient and true Spinning your eyeballs to capture the view [Outro] When sudden motion catches your gaze Thank the colliculus for those ancient ways Layered maps working in perfect time The midbrain's rhythm, the visual rhyme
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