BIZNIQUE / CALCULUS / 51
Understand vanishing gradients
Understand vanishing gradients
A chain of small local sensitivities can attenuate a signal dramatically.
BIZNIQUE / CALCULUS / 51
A chain of small local sensitivities can attenuate a signal dramatically.
THE IDEA
The illustration multiplies the same scalar sensitivity a across T steps. If |a| is below one, its magnitude shrinks with depth. Neural-network gradients involve richer chains of Jacobians, but this toy case makes one source of attenuation visible.
Repeated scalar sensitivity = aᵀ
Activation choice, initialisation, residual paths and gated structures can help in suitable models. None removes the need to inspect gradient flow and train under realistic conditions.
TRY IT YOURSELF
What is 0.5¹⁰?
1/1024, approximately 0.000977. A modest local shrinkage has accumulated across ten steps.