[Verse 1]
In the cortex where the neurons dance and fire
Synapses flow one way, that's their desire
But the theory calls for weights that mirror back
Symmetric paths the brain just seems to lack
Energy landscapes need that perfect balance
But biology presents a different challenge
[Chorus]
Weights don't flow both ways in neural streams
Random feedback breaks symmetric dreams
Approximate inverses learned with care
Excitation-inhibition pairs declare
Function over form will find a way
This thread returns throughout our learning day
[Verse 2]
Columns standing tall in organized arrays
Computing through their distributed maze
Each unit holds a piece of greater truth
Mathematical beauty meets biological proof
The awkward gap between what models need
And how the living circuits actually feed
[Chorus]
Weights don't flow both ways in neural streams
Random feedback breaks symmetric dreams
Approximate inverses learned with care
Excitation-inhibition pairs declare
Function over form will find a way
This thread returns throughout our learning day
[Bridge]
Watch the pattern emerge as we explore
Balanced forces opening every door
What seems impossible in cellular design
Gets solved by nature's alternatives divine
The function matters more than perfect form
Adaptation keeps the system warm
[Verse 3]
Unidirectional but functionally sound
Approximations where solutions are found
The cortex teaches us to think beyond
Rigid rules that theory might be fond
Random pathways serve the same true goal
While balanced currents play their vital role
[Verse 4]
Deep within the layers signals propagate
Forward through the network, learning how to calculate
Backprop needs its perfect mirror weights to teach
But evolution found what math said couldn't reach
Feedback alignment shows another way
Making learning work through nature's clever play
[Chorus]
Weights don't flow both ways in neural streams
Random feedback breaks symmetric dreams
Approximate inverses learned with care
Excitation-inhibition pairs declare
Function over form will find a way
This thread returns throughout our learning day
[Outro]
Keep this lesson close as concepts grow
The brain's solutions that we've come to know
Will surface again in every chapter's turn
More patterns and pathways we're bound to learn
[Final Chorus]
Weights don't flow both ways in neural streams
Random feedback breaks symmetric dreams
Function over form will find a way
This thread returns throughout our learning day